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Developing Applications for Event Processing with Oracle Stream

1. 3 9 Create and Register a Map Event Type First identify the event data that the event type carries and then decide the properties the event type requires You create a java util map event type by adding the configuration XML to the application assembly file An event type based on a hash map is called a map based event type e Data Types e To create and register a java util Map event type e Usages Data Types You can use the following Java types for the properties e The fully qualified name of a Java class The name must conform to the Class forName rules and be available in the application class loader 3 12 Developing Applications for Event Processing with Oracle Stream Explorer Create and Register a Map Event Type e A Java primitive such as int or float e An array by appending square brackets to the primitive or class name For example short or java lang Integer The following XML code shows examples of event property declarations in the event repository lt wlevs event type repository gt lt wlevs event type type name AnotherEvent gt lt wlevs properties type map gt lt wlevs property gt lt entry key name value Jjava lang String gt lt entry key employeeId value java lang Integer gt lt entry key salary value float gt lt entry key projectIds value short gt lt wlevs property gt lt wlevs properties gt lt wlevs event type gt lt wlevs event type reposi
2. 8 10 5 2 How to Access a Cache With JMX Using Java The simplest and least error prone way to access a caching system or cache with JMX is to use the Oracle Stream Explorer Visualizer see How to Access a Cache With JMX Using Oracle Stream Explorer Visualizer Alternatively you can access a caching system or cache with JMX using Java code that you write Oracle Stream Explorer creates a St ageMBean for each cache that your application uses as a Stage The Type of this MBean is Stage To access a cache with JMX using Java 1 Connect to the JMX service that Oracle Stream Explorer server provides For more information see Administering Oracle Stream Explorer Geta list of cache StageMbean using either of e CachingSystemMBean getCacheMBeans e ApplicationMBean getStageMBeans Get the Ob ject Name for a given StageMBean that represents a cache in your caching system ObjectName cacheName ObjectName getInstance com bea wlevs Name newCache Type Stage CachingSystem newCachingSystem Application provider i Get a proxy instance for the StageMBean with this Ob jectName StageMBean cache StageMBean MBeanServerInvocationHandler newProxyInstance server cacheName StageMBean class false i Use the methods of the St ageMBean to access the cache Cached Event Data 8 23 Access a Cache from Application Code 8 24 Developing Applications for Event Processing with Oracle Stream Explorer 9
3. Array of depth 1 of char Array of depth 1 of byte Array of depth 1 of char Array of depth 1 of char Array of depth 1 of byte An instance of java math BigDecimal Array of depth 1 of char An instance of java lang Object An instance of java lang Float An instance of java lang Integer For information about processing XMLTYPE data in Oracle CQL see Oracle CQL Language Reference for Oracle Stream Explorer An instance of java sql Time An instance of java sql Timestamp An instance of java lang Integer Array of depth 1 of byte Array of depth 1 of char For more information see Configure a Table Source Events and Event Types 3 5 Event Type Repository 3 4 Event Type Repository Oracle Stream Explorer manages event types in an event type repository The Oracle Stream Explorer server accesses the assembly file at run time to retrieve the information it needs to manage the application The following example shows an event type entry in the repository lt wlevs event type repository gt lt wlevs event type type name TradeEvent gt lt wlevs class gt tradereport TradeEvent lt wlevs class gt lt wlevs event type gt lt wlevs event type repository gt To define and edit event types you can use the Oracle JDeveloper Event tab work in the assembly file directly or call APIs from your application code The Event tab displays when you open the EPN diagram for an Oracle
4. The caching system creates the cache associated with a particular name and returns a reference to the cache The resulting cache bean implements the java util Map interface 4 Configure the third party caching system and its caches by updating the third party caching configuration file or files for the application Refer to your third party cache documentation 5 Optionally override the default third party cache configuration by updating the appropriate configuration file with one or more additional cache element child elements Refer to your third party cache documentation e Specify that a cache is an event sink by configuring it as a listener to another component in the event processing network e Specify that a cache is an event source to which another component in the event processing network listens e Configure a cache loader or store 6 When you assemble your application verify that the META INF MANIFEST MF file includes the following import com bea wlevs cache spi version lt version gt If the MANIFEST MF files does not include this import update the MANIFEST MF file to add this import before deploying your application 8 9 Exchange Data Between a Cache and Another Data Source You can have a cache in an EPN exchange data with another data source including a database For example you can load a cache with data when the application starts or create a read write relationship between the cach
5. The value n for the heartbeat time out on this adapter A heartbeat is generated when n time units go by without any event being generated on this adapter The default time unit is nanoseconds The batch size in terms of events for sending event time stamps to the secondary By default batching is disabled High Availability Applications 17 41 Configure High Availability Adapters 17 42 Developing Applications for Event Processing with Oracle Stream Explorer 18 Scalable Applications You can build scalability into your application design with partitioning and parallel processing and by taking high availability options into consideration Oracle Stream Explorer enables you to use default or custom partitioning and parallel processing settings on channels and the upstream adapter You can also partition an incoming JMS event stream and configure the JSMS Event stream group pattern matching This chapter includes the following sections e Default Channel Scalability Settings e Partition an Incoming JMS Event Stream e Notification Group Naming Conventions e Custom Channel Event Partitioner 18 1 Default Channel Scalability Settings You can configure a channel to use the default event property based event partitioner With this default configuration every time an incoming event arrives the channel selects a listener and dispatches the event to that listener instead of broadcasting every event to every listener
6. lt processor gt lt rules gt lt query id rule2 lt CDATA ISTREAM SELECT FROM StockTradeIStreamChannel ROWS 1 gt lt query gt lt rules gt lt processor gt 6 3 3 Processor Output Control Slides Instead of outputting query results as they happen you can use the SLIDE operator in a subclause to batch the output events You can batch the events based on the number of events when you use the ROW operator or an amount of time time window when you use the RANGE operator Note When a slide value is not specified the query assumes the default value of 1 row for tuple based windows and 1 time tick for time based windows Batch by Number of Events The following example outputs every 2 events 2 4 6 8 SELECT FROM StockTradeIStreamChannel ROWS 3 SLIDE 2 Oracle CQL Processors 6 7 Queries 6 3 4 Views The output from the SLIDE operator includes deleted events When the first two events arrive in the relation the query outputs both events to the stream When the next event arrives there are three events in the relation but output happens next at the fourth event When the fourth event arrives the first event is deleted and output with the third and fourth events The following example shows how to use a slide with the RSTREAM operator In this case when the fourth event arrives events 2 3 and 4 are sent to the output stream The RSTREAM operator sends all events to the output s
7. Id private String itemID private double targetPrice public String getItemID return itemID public void setItemID String itemID this itemID itemID public double getTargetPrice return targetPrice public void setTargetPrice double targetPrice this targetPrice targetPrice 9 3 2 3 PriceTargetLoader java package com oracle cep sample import java util ArrayList 9 8 Developing Applications for Event Processing with Oracle Stream Explorer JPA Coherence Example import import import import import import import public java util List javax persistence EntityManager javax persistence EntityManagerFactory javax persistence Persistence javax persistence Query org springframework beans factory DisposableBean com bea wlevs ede api InitializingBean class PriceTargetLoader implements DisposableBean InitializingBean private static final String PERSISTENCE_UNIT_NAME derby static ArrayList lt PriceTarget gt s_entriesToLoad new ArrayList lt PriceTarget gt j static setUpEntriesToLoad private EntityManagerFactory m_entityMgrFactory private EntityManager m_entityMgr public void afterPropertiesSet m_entityMgrFactory Persistence createEntityManagerFactory PERSISTENCE_UNIT_NAME m_entityMgr m_entityMgrFactory createEntityManager m_entityMgr getTransaction begin try Query q m_entityMgr createQuery SELECT t FROM PriceTarget t WHERE t it
8. 17 3 2 Primary Failure and Failover When a primary server fails as Figure 17 4 shows Oracle Stream Explorer performs a failover that can cause missed or duplicate events depending on the quality of service you choose High Availability Applications 17 3 Deployment Group and Notification Group Figure 17 4 Primary Failure and Failover Input Streams Multi Server Domain Deployment Group and Notification Group Server 1 Server 2 Server 3 Primary Secondary Queue Output Streams During failover Oracle Stream Explorer selects a new primary and the new primary transitions from the SECONDARY state to the BECOMING_PRIMARY state Depending on the quality of service you choose the new primary does not transition to PRIMARY state until a configurable readiness threshold is met For details see the specific quality of service option in Choose a Quality of Service Option 17 3 3 Rejoining the High Availability MultiServer Domain When a new Oracle Stream Explorer server is added to an Oracle Stream Explorer high availability multiserver domain or an existing failed server restarts the server does not fully join the Oracle Stream Explorer high availability deployment and notification groups until all applications deployed to it have fully joined The type of application determines when it can fully join If the application must generate exactly the same sequence of output events as existing secondaries a Type 1 application
9. Note Batching is not supported when you configure a channel with an event partitioner Figure 18 1 shows an EPN that uses an event partitioner property to partition a channel In this example the inbound adapter sends events of type PriceEvent which has two properties stock symbol and stock price The example partitions the channel on the symbol property and shows you how to add multithreading to either the channel or the upstream adapter Figure 18 1 EventPartitioner EPN processor 1 a _ta _B EventPartitionerChannel channel inbound processor2 outbound processor3 Scalable Applications 18 1 Default Channel Scalability Settings Configure Partitioning on the Channel Configure Parallel Processing on the Channel Configure Parallel Processing on the Upstream Adapter Define a Local Partition Channel 18 1 1 Configure Partitioning on the Channel See Customizing Oracle Stream Explorer for information about customizing an event partitioner on a channel 1 Add a channel to your EPN In Figure 18 1 the channel is EventPartitionerChannel Connect the channel to an upstream adapter In Figure 18 1 the upstream adapter is inbound Connect the channel to two or more listeners In Figure 18 1 the channel is connected to Oracle CQL processors processor1 processor2 and processor3 Edit the assembly file to add a partitionByEventProperty instance property to the channel element The value
10. The adapter or event bean that requires JAXB functionality obtains the functionality by injection of a bean that implements the com oracle cep mappers api Mapper interface The Mapper interface follows public interface Mapper Marshaller createMarshaller throws MapperException Unmarshaller createUnmarshaller throws MapperException The adapter or other EPN component code uses the injected bean to create marshalling and unmarshalling objects The com oracle cep mappers api Marshaller and com oracle cep mappers api Unmarshaller interfaces shown below work for most applications Adapters 4 3 JAXB Support public interface Marshaller void marshal Object object javax xml transform Result result throws MapperException public interface Unmarshaller Object unmarshal javax xml transform Source source throws MapperException Some applications might need specialized method signatures for marshalling and unmarshalling such as an unmarshall method that takes the target class as an argument In these cases use the com oracle cep mappers jaxb JAXBMarshalleriImpl and com oracle cep mappers jaxb JAXBUnmarshallerImplinterfaces instead These interfaces provide methods that correspond to the full set of marshall and unmarshall methods that are supported by the javax xml bind Marshaller and javax xml bind Unmarshaller interfaces Assembly File The following assembly file entries call a mapper bean with properties t
11. gt lt wlevs properties gt lt wlevs event type gt lt wlevs event type repository gt Day to second combinations INTERVAL DAY day_precision TO SECOND fractional_seconds_precision day_precision is the number of digits in the DAY date time field Accepted values are 0 to 9 The default is 2 fractional_seconds_precision is the number of digits in the fractional part of the SECOND date time field Accepted values are 0 to 9 The default value is 6 Year to month combinations INTERVAL YEAR year_precision TO MONTH year_precision is the number of digits in the YEAR date time field The default value for year_precisionis2 3 6 2 Time Stamp with Local Time Zone Properties The following assembly file entries show the time stamp with local time zone properties lt wlevs event type repository gt lt wlevs event type type name IntervalDataTypeEvent gt lt wlevs properties gt lt wlevs property name Comment type char length 256 gt lt wlevs property name timestamptzProp type timestamp with time zone gt lt wlevs property name timestampltzProp type timestamp with local time zone gt lt wlevs properties gt Events and Event Types 3 7 Create and Register a JavaBean Event Type lt wlevs event type gt lt wlevs event type repository gt With time zone TIMESTAMP fractional_seconds_precision WITH TIME ZONE fractional_seconds_precision optio
12. lt wlevs adapter gt 6 Configure the Oracle Stream Explorer high availability input adapter Consider using one of the following example configurations This example shows a high availability input adapter configuration using all defaults The mandatory key is based on all event properties and the event property that the high availability input adapter assigns a time value to is an event property named arrivalTime 17 30 Developing Applications for Event Processing with Oracle Stream Explorer Configure High Availability Quality of Service lt wlevs adapter id myHaInputAdapter provider ha inbound gt lt wlevs instance property name timeProperty value arrivalTime gt lt wlevs adapter gt This example shows a high availability input adapter configuration using all defaults The mandatory key is based on all event properties and the event property that the high availability input adapter assigns a time value to is an event property named arrivalTime Because the events are tuple based events you must specify the event type MyEvent Type using the event Type property lt wlevs adapter id myHaInputAdapter provider ha inbound gt lt wlevs instance property name timeProperty value arrivalTime gt lt wlevs instance property name eventType value MyEventType gt lt wlevs adapter gt This example shows a high availability input adapter configuration where the mandatory key is based on one event property
13. public int getAccountID return accountID public setOrderID int accountID this accountID accountID public int hashCode int hash 1 ash hash 31 timeProperty hashCode ash hash 31 accountID null 0 accountID hashCode return hash public boolean equals Object obj if obj this return true if obj null return false if obj instanceof MyCompoundKeyClass return false MyCompoundKeyClass k MyCompoundKeyClass obj return k accountID accountID amp amp k orderID orderID Optionally configure the component configuration file to include the Oracle Stream Explorer high availability input adapter and buffering output adapter as shown lt processor gt lt name gt helloworldProcessor lt name gt lt rules gt lt query id helloworldRule gt lt CDATA select from helloworldInputChannel Now gt lt query gt lt rules gt lt processor gt lt ha ha inbound adapter gt lt name gt myHaInputAdapter lt name gt lt ha ha inbound adapter gt lt ha ha broadcast adapter gt lt name gt myHaBroadcastAdapter lt name gt lt trimming interval units events gt 10 lt trimming interval gt lt ha ha broadcast adapter gt If your application is an Oracle Stream Explorer high availability Type 1 application where the application must generate exactly the same sequence of output events as existing secondaries configure the warm up win
14. then it must be able to rebuild its internal state by processing input streams for some finite period of time the warm up window length period This warm up window length time determines the minimum time it takes for the application to fully join the Oracle Stream Explorer high availability deployment and notification groups If the application does not need to generate exactly the same sequence of output events as existing secondaries a Type 2 application then it does not require a warm up window length time and fully joins the Oracle Stream Explorer high availability deployment and notification groups when it deploys For more information see Choose an Adequate warm up window length Time 17 4 Deployment Group and Notification Group All of the servers in the multiserver domain belong to the same deployment group the deployment group is the group to which you deploy an application For the purposes of Oracle Stream Explorer high availability you must deploy the same application to all of the servers in this group By default all of the servers in the multiserver domain also belong to the same notification group The servers listen to the notification group for membership notifications that indicate when a server fails and exits the group or resumes operation and rejoins the group and for synchronization notifications from the primary 17 4 Developing Applications for Event Processing with Oracle Stream Explorer High
15. 10 4 Supported Platform Senere n aeei A R AA E ARE EEA 10 1 10 2 Invoke a Web Service From an Application ssssssssssssssessesssstessessesnsstessesnnsnentesresnesneneeseess 10 1 10 3 Expose an Application as a Web Service ccccccscecccscesseseststeeseececeseseecaenesesesnsnensseseseeseseseeeeney 10 2 Parameterized Applications 11 1 Application ParametetSuniisisi eni an eee a Ene aE OA VEE A a Ee EEE RERE A 11 1 112 Object Class Definitions osrin en A e Nestea E AAE AE a Eta e SE AEEA 11 2 11 3 Attribute DescriptHhons ises an en A E E AAE A A a ees AOA 11 2 ILA Targeting eiei a e a R A A A A E E A AE EAER 11 2 11 5 Examplemetaty ype Biles s s rcs teins fone Seas tes states Ree E E aan E EAE 11 3 11 6 Where You Can Use Parameterized Applications ccccccecccecsccenetetesestsneieesceeeneseseeenes 11 4 11 6 1 Document an Application iseis eeir eip eatae iniae eiae esken koks 11 4 11 6 2 Channel Configuration ccccccccscesescsesneneseseseeesesescecesescsesnansnssesesnesesescecenesesssnsnanenens 11 4 11 6 3 Oracle CQL Processor QuUETY cccccsssesssecsessneesescsessesesescsesesesesescsesssesesesesessseseseseee 11 5 11 7 Deploy the HelloWorld Application cccccccccceesseeesesteteesescecescseecenenesesesnsensneeceeeeseseenanes 11 5 Internationalization 121 Message Catalogs iims retested iors reads aires etase o EE ree n aaia oaeen le eere ARNEE E 12 1 121A Hierarchy ei eein oieee ahi Ge ae oieee NE Gnd E
16. 399 100 0 private boolean m suspended private Thread m_thread private StreamSender m_sender private Map m_priceTargetCache public void setPriceTargetCache Map cache m_priceTargetCache cache public void afterPropertiesSet pre load PriceTarget cache for PriceTarget target PriceTargetLoader s_entriesToLoad System out println Getting target getItemID m_priceTargetCache get target getItemID public void run m_thread Thread currentThread m_suspended false send random sale events Random random new Random System currentTimeMillis while isSuspended int index random nextInt s_itemIDs length SaleEvent event new SaleEvent s_itemIDs index s_prices index m_sender sendInsertEvent event try synchronized this wait SLEEP_MILLIS catch InterruptedException e if isSuspended EclipseLink JPA and Oracle Coherence 9 11 JPA Coherence Example return public void setEventSender StreamSender sender m_sender sender public synchronized void suspend m_suspended true if m_thread null m_thread interrupt private synchronized boolean isSuspended return m suspended 9 12 Developing Applications for Event Processing with Oracle Stream Explorer 10 Web Services You can use web services platforms to integrate an Oracle Stream Explorer application with other systems This chapter explains h
17. 4 Inthe EPN assembly file update the configuration of the processor that executes the Oracle CQL query that references a cache a Ifthe cache is a processor source you connect the cache directly to the processor on the EPN as Figure 8 1 shows Figure 8 1 Cache as Processor Source DB e 52 cacheProcessor Bean stockCache adapter Update the wlevs processor element a wlevs cache source child element that references the cache For example Cached Event Data 8 19 Access a Cache from Application Code lt wlevs channel id S1 gt lt wlevs processor id cacheProcessor gt lt wlevs source ref S1 gt lt wlevs cache source ref cache id gt lt wlevs processor gt In the example the processor will have data pushed to it from the 1 channel as usual however the Oracle CQL queries that execute in the processor can also pull data from the cache id cache When the query processor matches an event type in the FROM clause to an event type supplied by a cache such as CompanyEvent the processor pulls instances of that event type from the cache b If the cache is a processor sink you must connect the processor to the cache using a channel on the EPN that is there must be a channel between the processor and the cache sink as Figure 8 2 shows Figure 8 2 Cache as Processor Sink an gt gt B channel1 channel2 adapter processor cache id In this case the application assembly file looks like
18. Copy the application library JAR to the appropriate Oracle Stream Explorer server application library directory a If your bundle is a driver you put it in the library extensions directory See Library Extensions Directory b If your bundle is not a driver you can put it in the library directory See Library Directory Stop and start the Oracle Stream Explorer server See Administering Oracle Stream Explorer Assemble and Deploy 13 13 Deploy an OSGi Bundle 13 8 Deploy an OSGi Bundle After you assemble your Oracle Stream Explorer application or library into an OSGi bundle you deploy it to an Oracle Stream Explorer server domain You can deploy an application with Oracle JDeveloper Oracle Stream Explorer Visualizer and with the Deployer utility This section explains how to use the Deployer utility With the Deployer utility you can deploy an application to either a stand alone or multiserver domain You can only deploy to a group when the server is part of a multiserver domain clustering is enabled You cannot deploy to a group when the server is part of a standalone server domain clustering is disabled Oracle Stream Explorer uses the deployments xml file to internally maintain a list of deployed OSGi bundles This file is located in the DOMAIN_DIR servername directory where DOMAIN_DIR refers to the main domain directory corresponding to the server instance to which you are deploying your application and serverna
19. Djava net preferIPv4Stack true parameter to the last line of the startwlevs sh script Note Spatial sample is not supported on AIX Platform EclipseLink JPA and Oracle Coherence 9 1 HelloWorld Example 9 2 HelloWorld Example The HelloWorld example uses EclipseLink to establish a read and write JDBC connection to the data source to access and store HelloWorld events In this example HelloWorld events contain date and time information The example is comprised of the following files which are discussed in this section e persistence xml Configuration File e HelloWorldAdapter java e HelloWorldEvent java e HelloWorldBean java 9 2 1 persistence xml Configuration File The following persistence xml file has one persistence unit persistence unit called helloworld The helloworld persistence unit has a transaction type of RESOURCE_LOCAL because Oracle Stream Explorer is a Java SE environment The EclipseLink properties specify the settings for database read and write operations and logging For this example the managed persistable class that represents objects in the database is com bea wlevs event example helloworld HelloWorldEvent This persistence xml file has entries for JPA logging that are commented out and set to false You can uncomment these settings and set them to t rue to debug or otherwise monitor the application behavior For information on property settings see http eclipse org eclipseli
20. Oracle Stream Explorer does not support QuickFIX dynamic acceptor sessions in the 12c release The QuickFix adapter does not support SSL 4 13 1 Supported QuickFIX Versions and Unsupported Message Types The QuickFIX engine supports a wide range of message types and validates the data in those message types If your Oracle Stream Explorer application requires a message that is not supported by the QuickFIX engine you must create a custom handler by extending the default QuickFIX message handler and overriding the appropriate handler method s The QuickFIX adapter supports the following QuickFIX versions The messages listed under each QuickFIX version are not supported QuickFIX Version 4 0 The following message types are not supported in this version Heartbeat Logon TestRequest ResendRequest Reject SequenceReset Logout QuickFIX Version 4 1 The following message types are not supported in this version Heartbeat Logon TestRequest ResendRequest Reject SequenceReset Logout QuickFIX Version 4 2 The following message types are not supported in this version Heartbeat Logon TestRequest ResendRequest Reject SequenceReset Logout QuickFIX Version 4 3 The following message types are not supported in this version Heartbeat Logon TestRequest ResendRequest Reject SequenceReset Logout Adapters 4 19 QuickFix Adapter QuickFIX Version 4 4 The following message types are not supported in this version He
21. The XMLTYPE property is not supported for table sources 6 5 2 Configuration File 6 10 lt data source gt lt name gt StockDs lt name gt lt connection pool params gt lt initial capacity gt 1l lt initial capacity gt lt max capacity gt 10 lt max capacity gt lt connection pool params gt Developing Applications for Event Processing with Oracle Stream Explorer Configure an Oracle CQL Processor for Parallel Query Execution lt driver params gt lt url gt jdbe derby lt url gt lt driver name gt org apache derby jdbc EmbeddedDriver lt driver name gt lt properties gt lt element gt lt name gt dat abaseName lt name gt lt value gt db lt value gt lt element gt lt element gt lt name gt create lt name gt lt value gt true lt value gt lt element gt lt properties gt lt driver params gt lt data source params gt lt jndi names gt lt element gt StockDs lt element gt lt jndi names gt lt global transact ions protocol gt None lt global transactions protocol gt lt data source params gt lt data source gt After configuration you can define Oracle CQL queries that access the Stock table as if it were another event stream In the following example the query joins the StockTradeIStreamChannel event stream to the Stock table SELECT StockTradeIStreamChannel symbol StockTradeIStreamChannel price StockTradeIStream lastPrice StockTradeIStream percChange StockTradeIStream vol
22. The application class definition can then be a target for multiple designates components of the same type to enable the reuse of definitions To prevent ambiguities each designate can be associated with one object class definition only Oracle Stream Explorer supports the following designates e Adapter Oracle CQL Processor event bean or Spring bean 11 2 Developing Applications for Event Processing with Oracle Stream Explorer Example metatype File e Oracle CQL processor rules such as a query or a view In the case of a rule the designate ID must identify the parent component followed by the subcomponent For example hel loworldProcessor ql Oracle Stream Explorer assigns a parameter to an application component after the call to the afterPropertiesSet life cycle method but prior to the call to afterConfigurationActive life cycle method This timing enables an application to treat an application parameter as a proper application configuration and to distinguish an application parameter from a bean property An ocep binding attribute determines how Oracle Stream Explorer assigns the parameter to the application Put the ocep binding attribute in the OCD or in the AD When you put it in the OCD the meta object is bound to an implementation object such as JMX Ob ject Instance When you put the OCD in an AD the meta attribute is bound to an implementation attribute scoped to the implementation object such as JMX MBean attri
23. adapters channels and event beans Processors and channels always produce events Adapters and event beans must implement the Event Source interface You can configure events from different components in the EPN to be stored in different persistent stores or that all events go to the same store Only events that are output by the component are recorded You enable the recording of events for a component by updating its configuration file and adding the record parameters element Using the child elements of record 15 2 Developing Applications for Event Processing with Oracle Stream Explorer Play Back Events parameters you specify the event store to which the events are recorded an initial time period when recording should take place the list of event types you want to store and so on After you deploy the application and events start flowing through the network recording begins either automatically because you configured it to start at a certain time or because you dynamically start it using administration tools For each component you have configured for recording Oracle Stream Explorer stores the events that flow out of it to the appropriate store along with a time stamp of the time it was recorded 15 4 Play Back Events You can configure playback for any component in the EPN processors adapters streams and event beans Typically the playback component is a stage later in the network than the stage that recorded
24. com bea wlevs channel EventPartitioner interface Click OK A new EventPartitioner class is created Complete the implementation of your EventPartitioner as shown package com acme import com bea wlevs channel EventPartitioner import com bea wlevs ede api EventProcessingException import com bea wlevs ede api EventType public class MyEventPartitioner implements EventPartitioner private final EventType eventType private int numberOfPartitions Override public void activateConfiguration int numberOfPartitions EventType eventType this numberOfPartitions numberOfPartitions this eventType eventType Override public int partition Object event throws EventProcessingException int dispatchToListener 0 Your implementation return dispatchToListener Scalable Applications 18 13 Custom Channel Event Partitioner The activateConfiguration method is a callback that the Oracle Stream Explorer server invokes before ActivatableBean afterConfigurationActive and before your EventPartitioner class s partition method is invoked When you associate this EventPart itioner with a channel the channel will invoke your EventPartitioner class s partition method each time the channel receives an event Your partition method must return the index of the listener to which the channel should dispatch the event The index must be an int between 0 and numberOfPartitions 1 9 Add a cha
25. e nanos wait the specified number of nanoseconds e millis wait the specified number of milliseconds e secs wait the specified number of seconds Default Heartbeats are not sent batch size Specify the number of events in each timing message that the primary broadcasts to its secondaries A value of n means that n key time pairs are sent in each message You can use this property for performance tuning Default 1 disable batching 17 10 2 Configure the Buffering Output Adapter The Oracle Stream Explorer high availability buffering output adapter is implemented by the SlidingWindowQueueTrimmingAdapter interface Assembly File The root element for declaring an Oracle Stream Explorer high availability buffering output adapter is wlevs adapter with provider element set to ha buf fering as the following example shows lt wlevs adapter id mySlidingWindowingAdapter provider ha buffering gt lt wlevs listener gt lt bean class com bea wlevs example cluster ClusterAdapterBean gt lt wlevs listener gt 17 36 Developing Applications for Event Processing with Oracle Stream Explorer Configure High Availability Adapters lt wlevs instance property name windowLength value 15000 gt lt wlevs adapter gt Table 17 6 describes the additional child elements Table 17 6 Child Elements Child Element Description wlevs listener Specify the regular output adapter downstream from this Oracle Stream Ex
26. lt csv adapter gt lt csv adapter gt lt name gt StockTradeCSVOutboundAdapter lt name gt lt csv adapter gt 4 6 EDN Adapters Event Delivery Network EDN inbound and outbound adapters use JAXB to enable an EPN to interface with an Oracle SOA Suite event network The EDN adapters have a raw xml content configuration element that specifies whether to represent the EDN XML data transmission as raw XML if true or as a Java object using JAXB In the JAXB case the adapter expects the Oracle Stream Explorer application bundle to include the appropriate set of schema x jc generated classes on its class path You configure an EDN adapter with an event type and a reference to an EDL file During initialization the adapter searches the EDL file that contains an event definition QName that matches the configured event type If the configured event type is found in the EDL the adapter registers a subscription with EDN for the corresponding QName To learn how to use EDN adapters and an EDL file see Getting Started with Event Processing for Oracle Stream Explorer Adapters 4 7 EDN Adapters 4 6 1 Usage Use an EDNInbound adapter to receive incoming data from the Oracle SOA Suite event network The EDN input adapter subscribes to a specified EDN event type and converts the incoming EDN events to an Oracle Stream Explorer event type for processing by an Oracle Stream Explorer application Use an EDNOutbound adapter to send outbou
27. max threads gt lt channel gt lt channel gt lt name gt helloworldOutputChannel lt name gt lt max size gt 10000 lt max size gt lt max threads gt 2 lt max threads gt lt channel gt lt nl config gt 2 4 Component and Server Configuration Use the ConfigurationPropertyPlaceholderConfigurer class to reference existing configuration file properties in both component configuration and server configuration files using a symbolic placeholder This allows you to define a value in one place and refer to that one definition rather than hard coding the same value in many places Application and Resource Configuration 2 5 Resource Access Configuration You might want to do this if you want to configure Java Message Service JMS without hard coding JMS information such as the factory name in the assembly file for your Oracle Stream Explorer application Use the com bea wlevs spring support ConfigurationPropertyPlaceholderCon figurer class to create a JMS adapter and provide placeholders for the server connection factory name user name password and the location to a separate file that contains the actual factory name user name and password values The ConfigurationPropertyPlaceholderConfigurer class is implemented on top of the Spring framework The server configuration file is used by Oracle Stream Explorer server administrators This file contains configuration information that is specific to a domain and is located i
28. mnegt listapps Lists all deployed applications mnegt listlibs Lists all deployed libraries mngt mbean Retrieves the MBean stage from the local MBean server mnegt shutdown Shuts the server down mngt undeployapp Undeploys the specified application 14 14 Developing Applications for Event Processing with Oracle Stream Explorer EPN Command Interface 14 4 EPN Command Interface The EpnCommand interface is a Java API on top of the Oracle Stream Explorer EPN CQL programming model You can use the EpnCommand interface in a Java application to manipulate EPN components You can programmatically start an EPN session and execute EPN commands similar to using the command line EPN shell described in EPN Shell Use beginSession tostart an EPN session and endSession toend an EPN session Ending a session destroys all EPN components that were created during that session A session is not multithread aware and must be synchronized in your application code To use EPN commands in an Oracle Stream Explorer application first retrieve the EpnCommand OSGi service which registers the service as an OSGi service factory Once you retrieve the OSGi service you can create test cases similar to JUnit test cases for testing EPN components and Oracle CQL statements Only the commands exposed in the EpnCommand class as methods can be use for JUnit like test cases You can also use the EpnCommand interface to create an Oracle Stream Exp
29. named sequenceNo and the event property that the high availability input adapter assigns a time value to is an event property named inboundTime lt wlevs adapter id myHaInputAdapter provider ha inbound gt lt wlevs instance property name keyProperties value sequenceNo gt lt wlevs instance property name timeProperty value inboundTime gt lt wlevs adapter gt This example shows a high availability input adapter configuration where the mandatory key is based on more than one event property properties orderID and account ID and the event property that the high availability input adapter assigns a time value to is an event property named arrivalTime A compound key Java class com acme MyCompoundKeyClass is mandatory and its implementation is shown The hashCode and equals methods are required When you specify a keyClass the keyProperties instance property is ignored Oracle Stream Explorer assumes that the compound key is based on all the getter methods in the keyClass lt wlevs adapter id myHaInputAdapter provider ha inbound gt lt wlevs instance property name timeProperty value arrivalTime gt lt wlevs instance property name keyClass value com acme MyCompoundKeyClass gt lt wlevs adapter gt package com acme public class MyCompoundKeyClass private int orderID private int accountID public MyCompoundKeyClass public int getOrderID return orderID public setOrderID int
30. null return HashMap props new HashMap props put PersistenceUnitProperties NON_JTA_DATASOURCE m_ds props put eclipselink ddl generation create tables props put eclipselink ddl generation output mode database m_entityMgrFactory Persistence createEntityManagerFactory PERSISTENCE_UNIT_NAME props m_entityMgr m_entityMgrFactory createEntityManager public void onInsertEvent Object event if m_shuttingDown return setupEntityManager if event instanceof HelloWorldEvent HelloWorldEvent helloWorldEvent HelloWorldEvent event System out println Message helloWorldEvent getMessage m_entityMgr getTransaction begin try m_entityMgr persist helloWorldEvent m_entityMgr getTransaction commit finally if m_entityMgr getTransaction isActive m_entityMgr getTransaction rollback Query q m_entityMgr createQuery select t from HelloWorldEvent t List lt HelloWorldEvent gt hwlist gq getResultList System out println Stored hwlist size helloworld events m_eventSender sendInsertEvent event Resource name derbyDS public void setDataSource DataSource ds m_ds ds public void destroy m_shuttingDown true if abi m_entityMgr null1 m_entityMgr close m_entityMgr null m_entityMgrFactory null m_entityMgrFactory close m_entityMgrFactory null EclipseLin
31. representing property names and property values For the purpose of this document there is no need to define the domain of property names and property values EPN1 adapterl channell processor channel2 adapter2 adapterl channell channell processor processor channel2 channel2 adapter2 Example 5 2 EPN Example 2 As an EPN node may contain more than one event we define the set E as an ordered sequence of events Note Eis ordered which is different from other cases The runtime state S N E of the EPN can thus be presented as a two place relation from N to E Note that the relation S is not injective meaning that the same event s may be present in more than one node However it is surjective as all events of the total set of events in the EPN must be in at least one node el price 10 volume 200 symbol ORCL e2 pl vl p2 v2 p3 v3 Channels 5 7 Distributed Flows 5 8 Developing Applications for Event Processing with Oracle Stream Explorer 6 Oracle CQL Processors An Oracle CQL Processor processes incoming events from various input channels and other data sources You use Oracle CQL to write the business logic in the form of continuous queries that process incoming events Oracle CQL filters aggregates correlates and processes events in real time Note You can create a Java class with methods that enhance the functionality available in Oracle CQ
32. send helloworld helloworldInputChannel Sevent1l Subscribe to a channel The events subscribed to are sent either to the shell console or to a file when you specify a file name Make sure the channel is advertised by setting the advertise attribute to true in the assembly file The following command subscribes to all output from the helloworld application and send the output to the shell console g subscribe helloworld helloworldOutputChannel List all public advertised stages in the application g introspect helloworld Application helloworld provides the following OCEP services Event Channel helloworldOutputChannel for Event Type HelloWorldEvent Retrieve the CQLProcessorMBean for the helloworld Oracle CQL processor and invoke the getAl1Queries operation g proc mbean helloworld helloworldProcessor CQLProcessor g Sproc allQueries 14 12 Developing Applications for Event Processing with Oracle Stream Explorer EPN Shell helloworldRule select from helloworldInputChannel You can use the retrieved mbean with the mbean command to test and manipulate JMX operations Stop the server g stop 14 3 3 Regression Testing You can automate application testing by running the shell headless and using scripts For example you can execute the following script named send event cep by specifying the gosh args system property in the startwlevs command begin channel a a Long query select from ch0 send 0 a
33. 10 lt trimming interval gt lt warm up window length units minutes gt 6 lt warm up window length gt lt ha ha broadcast adapter gt Table 17 11 describes the additional child elements Table 17 11 Child Elements Child Element Description trimming interval Specify the interval at which trimming messages are broadcast as an integer number of units You can use this property for performance tuning see High Availability Performance Tuning Valid values for attribute units e events broadcast trimming messages after the specified number of events are processed e millis broadcast trimming messages after the specified number milliseconds Default units is events warm up window Specify the length of time it takes the application to rebuild state length after a previously failed secondary restarts or a new secondary is added Valid integer values for the units attribute e seconds wait the specified number of seconds e minutes wait the specified number of minutes Default units is seconds For more information see Choose an Adequate warm up window length Time 17 10 4 Configure the Correlating Output Adapter The Oracle Stream Explorer high availability correlating output adapter is implemented by the CorrelatedQueueTrimmingAdapter interface High Availability Applications 17 39 Configure High Availability Adapters Assembly File The root element to declare an Oracle Stream Explorer high av
34. Configuration sees sesssesssesesssssssssesesesssssseeseseseeeeees 4 13 4 10 3 Outbound Adapter Configuration ccccccccccseseseeseececeneseesenesesesesnsneeeseseeneseseeeenes 4 14 4 11 JMS Custom Message Converter Bean cccscccsesescscesesescsnsnsesesesneesescececesssesnaenesesssneneneseees 4 14 4 11 1 Implement Interfaces sssini eee ceeseeeseeeeceeeseeseesesesssesseesesssssssseesesesseseeeseseseseseeees 4 15 4 11 2 Implement the Inbound JMS Adaptet cccceee sees sssssseseesessssesseesessseeeenees 4 15 4 11 3 Implement the Outbound JMS Adapter 0 cece ee seesessesesesesseseeseneseesesenees 4 16 4 12 Oracle Business Rules Adapter ccccccescsssssessessseescecesesesceneesesesesnenesescececesssesnansnenesesneneneseees 4 17 413 QUICKFIx Adapter sss starteriai ae beckett ate Ee aeeai rana ea e a eS E 4 19 4 13 1 Supported QuickFIX Versions and Unsupported Message Types cccseeeee 4 19 4 13 2 Configure QuickFix Adapters gesprei en taei i ea O EAEE 4 20 4 13 3 Configure a Socket Based Acceptor Failover sssssssssssissestsesesrissestersesresneseenseseesses 4 20 ATA REST Adapteisoi siem Saen E E E E EAN E EEEa EEE 4 21 ANS RMU Adapters isc snema eea a E a e EE A E a E E EEE 4 22 Channels SR Whe nto Usea Chanel ssr crsssisesi ninan ainn i a i As es ed 5 1 5 2 Channel Configuration semean a Ae a e e EE AE E coke E EE A E 5 2 92 ASSEMBLY File mses aee e A N E E E EE AAE E RES 5 2 52 2 Configuration File na
35. E E E E GMa eda ihe Ae Move ste 14 8 14 22 59 Trace Events oitesce cieds sethens dackiu cde iadieh beleecSidive colic adhe tacks Madbotedasbsb ates leibaaeeeed heehee de esecned 14 8 T426 Evet Inspector AP Lorimer niee oiei a eeta osae t hirae etai 14 9 TAS ERN Shelli neiii no a eaat e i e lB Mak oak AES e ane ae a e bel oo ae 14 10 14 3 1 Oracle COL QUEHES aen a a SAR a a 14 11 14 3 2 Management Commands casse sesasi e s EE rea aE E Ee s 14 11 14 3 3 Regression Testing esen iei se e a a a eaaa 14 13 14 34 EPN Variable x i242 5 n asta eiedeetik a Wa nena i oe Man 14 13 14 3 5 EPN Commands 21 ites ic tcosd aii pert hal eee beideieves oh a a i siren eens 14 13 14 3 6 Management Commands ccccccccccscscsssnsiesesesseneeseececesescsnansssessseeeseseseecesesescsnanenens 14 14 15 14 4 EPN Command Interfaces cciicccccegccccosees codec ccagececdsdavcesdesecdescecedasdesdiusocaderaceterstcssuvsecdotiedusevasexaneeess 14 15 14AT Session Variables seiiet tei ba hoe esas aa ee deste dal Lk os ab veg hehe ea eats 14 15 144 2 Method se sisne iedit oeeie fa See Os Nhe Gedo fel Eo eS EE Ea eats 14 15 LA ATS TX AIP LO iir aTe ED ce tte Be SN A eS ial SS Mia tales a esac eusdae api 14 16 Debug with Event Record and Playback T51 VE Verit POW sasdisecvaxthienind deanein ental ha a ne ann ein amet dna ee beans 15 1 T5 2 Berkeley D E E E E edt beab kali ged abate Seep EE 15 2 15 3 Recort BVemts is sete Sel heehee Leh ON AE sie eid EE
36. Explorer provides application design patterns and high availability adapters to enable you to increase the backup and failover processing capabilities of you applications This chapter includes the following sections Oracle Coherence Architecture Life Cycle and Failover Deployment Group and Notification Group High Availability Adapters High Availability and Scalability Choose a Quality of Service Option Design Applications for High Availability Configure High Availability Quality of Service Configure High Availability Adapters 17 1 Oracle Coherence Oracle Stream Explorer high availability options depend on Oracle Coherence You cannot implement Oracle Stream Explorer high availability options without Oracle Coherence When considering performance tuning be sure to evaluate your Oracle Coherence configuration in addition to your Oracle Stream Explorer application For more information see High Availability Performance Tuning Administering Oracle Stream Explorer Oracle Coherence Developer s Guide at http download oracle com docs cd E15357_01 coh 360 e15723 toc htm 17 2 Architecture Oracle Stream Explorer supports an active active high availability architecture This approach has the advantages of high performance simplicity and short failover time to mitigate the likelihood and impact of data and service faults High Availability Applications 17 1 Life Cycle and Failover Deploy high availability app
37. Ingress and Egress Points Preserve What You Need Limit Oracle Stream Explorer Application State Choose an Adequate warm up window length Time Ensure Applications are Idempotent Source Event Identity Externally Understand the Importance of Event Ordering Write Oracle COL Queries with High Availability in Mind Avoid Coupling Servers Plan for Server Recovery 17 8 2 1 Select the Minimum High Availability Your Application can Tolerate Be sure that the extra cost of precise recovery per stage throughput decrease is actually necessary for your application High Availability Applications 17 13 Design Applications for High Availability 17 8 2 2 Use High Availability Components at All Ingress and Egress Points Use a high availability input adapter after each regular input adapter and use a high availability output adapter before each regular output adapter 17 8 2 3 Preserve What You Need Oracle Stream Explorer systems receive a large number of raw input events that are queried to generate a smaller number of relevant events In general it makes sense to preserve the relevant event because there are fewer of them and they are more valuable 17 8 2 4 Limit Oracle Stream Explorer Application State Oracle Stream Explorer systems enable you to query windows of events It can be tempting to build systems with very large windows but this increases the state that needs to be rebuilt when failure occurs In general it is better to
38. Oracle Stream Explorer Notification Group Naming Conventions lt wlevs channel id channel2 event type StockTick gt lt wlevs listener ref myHaCorrelatingAdapter gt lt wlevs channel gt lt wlevs adapter id myHaCorrelatingAdapter provider ha correlating gt lt wlevs instance property name correlatedSource ref clusterCorrelatingOutstream gt lt wlevs instance property name failOverDelay value 2000 gt lt wlevs listener ref JMSOutboundAdapter gt lt wlevs adapter gt lt wlevs adapter id JMSOutboundAdapter provider jms outbound gt lt wlevs adapter gt lt wlevs adapter id JMSInboundAdapter2 provider jms inbound gt lt wlevs adapter gt lt wlevs channel id clusterCorrelatingOutstream event type StockTick advertise true gt lt wlevs source ref JMSInboundAdapter2 gt lt wlevs channel gt lt beans gt Example 18 4 Precise Recovery With JMS Component Configuration Assembly File lt xml version 1 0 encoding UTF 8 gt lt wlevs config xmlns wlevs http www bea com ns wlevs config application xmlns ha http www oracle com ns cep config cluster gt lt processor gt lt name gt processor1 lt name gt lt rules gt lt query id helloworldRule gt lt CDATA select from channell Now gt lt query gt lt rules gt lt processor gt lt jms adapter gt lt name gt JMS InboundAdapter lt name gt lt event type gt StockTick lt event type gt lt
39. Reference for Oracle Stream Explorer The EPN assembly file has a top level root element named beans that contains a sequence of sub elements Each individual sub element contains the configuration data for an Oracle Stream Explorer component lt xml version 1 0 encoding UTF 8 gt lt beans xmlns http www springframework org schema beans xmins xsi http www w3 org 2001 XMLSchema instance xmlns osgi http www springframework org schema osgi xmlns wlevs http www bea com ns wlevs spring xsi schemaLocation http www springframework org schema beans http www springframework org schema beans spring beans xsd http www springframework org schema osgi http www springframework org schema osgi spring osgi xsd http www bea com ns wlevs spring http www bea com ns wlevs spring spring wlevs v12_1_3_0 xsd gt lt wlevs event type repository gt 2 2 Developing Applications for Event Processing with Oracle Stream Explorer Assembly File Structure lt wlevs event type type name HelloWorldEvent gt lt wlevs class gt com bea wlevs event example helloworld HelloWorldEvent lt wlevs class gt lt wlevs event type gt lt wlevs event type repository gt lt wlevs adapter id helloworldAdapter class com bea wlevs adapter example helloworld HelloWorldAdapter gt lt wlevs instance property name message value HelloWorld the current time TS gt lt wlevs adapter gt lt wlevs channel id helloworldInpu
40. Stream Explorer Visualizer Parameterized Applications 11 5 Deploy the HelloWorld Application startwleves sh shell Oracle CEP Shell using Apache Felix Gogo shell gt shell gt deployapp file Users myuserid helloworld jar HelloWorld Sample The helloworld OEP application is a sample application for Oracle OEP Enter Y N default is Y if you would like to set the parameter Max Threads Application parameter Max Threads Description Number of threads generating helloworld messages Type Integer Default value 2 Enter value for Max Threads or empty for default value Using default value of 2 Application parameter Filter Description Message filter Type String Options for parameter Filter are 0 Select all messages starting with Hello 1 Select all messages starting with Hi Select option by entering number 0 1 or empty for default value lt Jan 23 2012 7 20 40 AM EST gt lt Notice gt lt Deployment gt lt BEA 2045000 gt lt The application bundle helloworld was deployed successfully gt lt Jan 23 2012 7 20 41 AM EST gt lt Notice gt lt Spring gt lt BEA 2047000 gt lt The application context for helloworld was started successfully gt Message HelloWorld the current time is 7 20 41 AM Message HelloWorld the current time is 7 20 42 AM 11 6 Developing Applications for Event Processing with Oracle Stream Explorer 12 Internationalization You can use me
41. StreamSink A class that receives events as a stream only receive events that are from the Oracle Stream Explorer standpoint inserted That is because in a stream events are always appended to the end of a sequence Events in a stream are also always received in ascending time order so that their time stamps have non decreasing values from one event to the one that follows Non decreasing time stamps enables the time stamp of one event to be the same as the time stamp of the event that precedes it but not earlier than that preceding time stamp The time stamp is either the same or later As a result the interfaces that support receiving events as a stream have one method each for receiving events The interfaces for receiving events as a relation support receiving multiple kinds of events Implement the St reamS ink interface if your class receives unbatched events as a stream The St reamSink interface has a single method onInsertEvent which the Oracle Stream Explorer server calls to pass in each event from the stream as events leave the upstream stage that is connected to your class In Example 7 1 a simple St reamSink implementation that receives stock trade events where each event is an Object instance and tests to see whether the event is an instance of a particular event type If so then the code retrieves values of properties known to be members of that type 7 4 Developing Applications for Event Processing with Oracle Stream E
42. a Web Service javax xml soap javax xml transform javax xml transform stream javax xml ws javax xml ws spi org xml sax weblogic xml stax 6 Adda glassfish ws element to the Oracle Stream Explorer server DOMAIN_DIR config config xml file that describes your Oracle Stream Explorer domain where DOMAIN_DIR refers to your domain directory lt glassfish ws gt lt name gt JAXWS lt name gt lt http service name gt JettyServer lt http service name gt lt glassfish ws gt 10 4 Developing Applications for Event Processing with Oracle Stream Explorer 11 Parameterized Applications Parameterized Applications contain special parameters variables that must be configured before the application starts Generally you configure a parameterized application when you deploy the application with the Oracle Stream Explorer EPN shell After a parameterized applications is configured it functions as a regular application This chapter includes the following sections e Application Parameters e Object Class Definitions e Attribute Descriptions e Targeting e Example metatype File e Where You Can Use Parameterized Applications e Deploy the HelloWorld Application 11 1 Application Parameters Application parameters define property values that can be set when the user launches an application You can parameterize properties for adapters channels event beans Spring beans and Oracle CQL parameterized queries with and w
43. a set of the nodes vertices and C is a two place relation over N representing the connections arcs from a source node to a destination node This is known as a distributed flow Distributed Flow refers to a set of events in an application A distributed flow serves the same purpose as that of variables or parameters in computer programming languages The distributed flow represents a state that is communicated by a software layer A distributed flow is dynamic in nature A distributed flow expresses the high level logical relationship between parts of distributed protocols A few scenarios in which distributed flows can be used are listed below e Events that are not extremely latency bound e Events that can be logically partitioned e Events that can be logically divided into separate individual components tasks that can be executed in parallel Properties of Distributed Flow A distributed flow usually has the following properties 1 Asynchronous and one way each event represents a single instance 2 Homogeneous and uniform all events in the flow are uniform and are similar in nature Channels 5 5 Distributed Flows 3 Concurrent and distributed the events in the flow occur at different times concurrent and at different nodes distributed 5 7 1 Examples of Distributed Flows A few scenarios in which distributed flow can be used in real life are listed below Word Count In a scenario where you need to coun
44. acommon HTTP pub sub channel and server to trace and inject events Note Do not use the Event Inspector service on a production Oracle Stream Explorer server Use this service during development only A trace event must have its binding attribute set to outbound and an injected event must have its binding attribute set to inbound Using an Event Inspector client you can inject 14 4 Developing Applications for Event Processing with Oracle Stream Explorer Event Inspector Service e A single simple event by type such as the StockTick event The specific event property types that you can use depends on the client e A single event directly to the HTTP pub sub channel as a JSON formatted character string You can use any event property that JSON can represent e Multiple events using a file that contains one or more JSON formatted character strings You can use any event property that JSON can represent The Event Inspector service client parses the file and injects all of its JSON strings to the HTTP pub sub channel You can use the GSON Java library to help you convert Java objects to JSON format when creating your input file For more information see e http www json org e http code google com p google gson The Event Inspector service supports Oracle Stream Explorer Visualizer See Using Visualizer for Oracle Stream Explorer 14 2 1 Event Types The Event Inspector service supports all Oracle Stream Explorer eve
45. and Deploy 13 7 Assemble an OSGi Bundle with bundle sh com bea wlevs ede version 11 1 1 com bea wlevs ede api version 11 1 1 com bea wlevs ede impl version 11 1 1 org osgi framework version 1 3 0 org springframework beans factory version 2 5 6 org apache commons logging version 1 1 0 com bea wlevs spring version 11 1 1 com bea wlevs util version 11 1 1 org springframework beans version 2 5 6 org springframework util version 2 0 org springframework core annotation version 2 5 6 org springframework beans factory version 2 5 6 org springframework beans factory config version 2 5 6 org springframework osgi context version 1 2 0 org springframework osgi service version 1 2 0 e Exported packages Specified with the Export Package header You should specify this header only when you need to share one or more application classes with other deployed applications A typical example is sharing an event bean If possible you should export packages that include only the interfaces and not the implementation classes themselves If other applications use the exported classes you cannot fully undeploy the application that is exporting the classes Exported packages are server wide so be sure their names are unique across the server The following is the MANIFEST MF file from the HelloWorld example application Note Oracle Stream Explorer requires the following MANIFEST MF se
46. and sends the relation to the next EPN stage A relation is a window of time on the stream that has a beginning and an end Events in a relation can be inserted into deleted from and updated in the relation For insert delete and update operations events in a relation must be referenced to a particular point in time to ensure the operation takes place on the correct event All operations on a relation are time based Most applications do not use relation channels You can put a window of time on events coming from a stream channel to create a relation for time based processing operations To find the average price for a particular stock you must determine a time frame window in which to calculate the average When you define a window on a stream you have a collection of data that is not flowing and unlike a stream has a beginning and an end The window is an in memory relation on which you can apply a function such as AVG and also perform insert update and delete operations Operators that put a window of time on a stream are called stream to relation operators The output of stream to relation operations are relations You use relation to stream operators to convert a relation back to a stream to output a stream that contains every event only inserted events or only deleted events Oracle CQL processor output typically goes to a stream channel and on to the next stage in the EPN 6 3 2 1 Stream to Relation Operators The stream
47. back to data in a format that is suitable for the destination which could be for example storage display on a web page or further processing by another application If you are new to Oracle Stream Explorer application development start with Getting Started with Event Processing for Oracle Stream Explorer The getting started guide presents an overview of Oracle Stream Explorer provides hands on walkthroughs and describes the sample applications This guide explains how to create configure and deploy an Oracle Stream Explorer application with the components provided in the platform If you want to build an application with customized adapters or event beans see Customizing Oracle Stream Explorer This chapter includes the following sections e EPN Diagram e Component Configuration e Streams and Relations e Application Scalability and High Availability e Application Life Cycle e API Overview e Spring Framework e OSGi Service Platform 1 1 EPN Diagram Oracle Stream Explorer application development centers on the Event Processing Network EPN application model The EPN diagram represents how event data flows into through and out of an Oracle Stream Explorer application You assemble the EPN diagram in Oracle JDeveloper by selecting and configuring EPN components and providing logic as needed In an EPN diagram event data flows from left to right The figure shows the EPN diagram for the TradeReport application Data enter
48. been sent by the primary at a particular point in time Because events are only trimmed after they have been sent by the current primary this allows the secondary to avoid missing any output events when there is a failover The frequency with which the active primary sends queue trimming messages to active secondaries is configurable e Every n events n gt 0 This limits the number of duplicate output events to at most n events at failover 17 10 Developing Applications for Event Processing with Oracle Stream Explorer Choose a Quality of Service Option e Every n milliseconds n gt 0 The queue trimming adapter requires a way to identify events consistently among the active primary and secondaries The recommended approach is to use application time to identify events but any key value that uniquely identifies events works The advantage of queue trimming is that output events are never lost There is a slight performance overhead at the active primary however for sending the trimming messages that need to be communicated This overhead increases as the frequency of queue trimming messages increases During failover the new primary enters the BECOMING_PRIMARY state and does not transition into the PRIMARY state until its event queue that it was accumulating as a secondary has been flushed During this transition new input events are buffered and some duplicate events can be output When an Oracle Stream Explorer s
49. caching Oracle Stream Explorer local caching and caching solutions provided by third parties You can access the events in the caches with Oracle CQL and Java classes See Cached Event Data Introduction to Application Development 1 9 API Overview Packages e com bea wlevs cache spi package provides interfaces that enable you to create a caching system that can be used by Oracle Stream Explorer applications e com bea wlevs cache spi coherence package provides interfaces that enable you to extend the caching system to include Oracle Coherence caching Cache Loader The com oracle cep cacheloader package provides the CsvCacheLoader class for loading CSV events into a Coherence cache See Cached Event Data Cluster Group Management The com bea wlevs ede api cluster package provides interfaces for managing server groups within multiserver domains clusters You can get information about the configuration implement event beans and adapters to listen for cluster membership changes set the group name for the containing EPN and get information about a group server See Administering Oracle Stream Explorer Management Beans Management beans MBeans enable you to programmatically access configuration and runtime information to perform tasks There are two types of MBeans tasks configuration and run time Configuration MBeans contain information about EPN component configuration Run time MBeans contain information about compone
50. calls the setEvent Sender method to initialize the m_event Sender private variable with a St reamSender instance The onInserEvent method sends the events emitted by the St reamSource instance downstream to St reamSink listeners package com bea wlevs example helloworld import java util HashMap import java util List import javax annotation Resource import javax sql DataSource import javax persistence EntityManager import javax persistence EntityManagerFactory import javax persistence Persistence import javax persistence Query import org springframework beans factory DisposableBean import org eclipse persistence config PersistenceUnitProperties import com bea wlevs ede api StreamSink import com bea wlevs ede api StreamSource import com bea wlevs ede api StreamSender import com bea wlevs event example helloworld HelloWorldEvent public class HelloWorldBean implements StreamSink StreamSource 9 4 Developing Applications for Event Processing with Oracle Stream Explorer DisposableBean HelloWorld Example private private private private private private static final String PERSISTENCE_UNIT_NAME helloworld EntityManagerFactory m_entityMgrFactory EntityManager m_entityMgr DataSource m_ds boolean m_shuttingDown StreamSender m_eventSender public void setEventSender StreamSender sender m_eventSender sender private if void setupEntityManager m_entityMgr
51. can configure any processor adapter channel or event bean in your application to record events This section updates an adapter configuration to record events See Schema Reference for Oracle Stream Explorer for the complete XSD Schema that describes the event recording configuration file elements 1 Open the component configuration file and add a record parameters child element to the component you want to configure to record events as follows lt csv adapter gt lt name gt StockTradeCSVAdapter lt name gt lt record parameters gt lt record parameters gt lt csv dapter gt 2 Add child elements to record parameters to specify a data set name the list of one or more events to be stored the recording start and stop times and so on lt csv adapter gt lt name gt StockTradeCSVAdapter name gt lt record parameters gt lt dataset name gt recplay_sample lt dataset name gt lt event type list gt lt event type gt TradeEvent lt event type gt lt event type list gt lt time range gt lt start gt 2010 01 20T05 00 00 lt start gt lt end gt 2010 01 20T18 00 00 lt end gt lt time range gt lt record parameters gt lt csv adapter gt 15 4 Developing Applications for Event Processing with Oracle Stream Explorer Configure a Component to Record Events Table 15 2 lists the child elements of record parameters that you can specify Only dataset name is required Table 15 2 Child Elements of re
52. com bea wlevs example helloworld HelloWorldBean gt lt property name map ref cache id gt lt bean gt In the example the ref attribute of the property element references the id value of the wlevs cache element Oracle Stream Explorer automatically injects the cache implemented as a java util Map into the business POJO bean In the business POJO bean Java source add a setMap Map method with the code that implements whatever you want the POJO to do with the cache package com bea wlevs example helloworld import java util Map public class HelloWorldBean implements EventSink public void setMap Map map 8 10 4 Access a Cache From an Oracle CQL User Defined Function In addition to standard event streams Oracle CQL rules can also invoke the member methods of a user defined function These user defined functions are implemented as standard Java classes and are declared in the component configuration file of the Oracle CQL processor as shown in the following example Cached Event Data 8 21 Access a Cache from Application Code lt bean id orderFunction class orderFunction impl class gt The processor in which the relevant Oracle CQL rule runs must then be injected with the user defined function using the wlevs function child element referencing the Spring bean with the ref attribute lt wlevs processor id tradeProcessor gt lt wlevs function ref orderFunction gt lt wlevs processor
53. command registers the select query from MyChannel in the implicit Oracle CQL processor for this session You can remove the query from the processor with the remove command The send command dispatches an insert event to MyChannel If the session has a single channel only then the name of the channel is optional For example the following two commands are equivalent send MyChannel msg Hi and send msg Hi The syntax msg Hi creates a map that contains a single key value pair with a key of msg and a value of Hi This matches the event type created in the first line with channel MyChannel msg String You can use the update and delete commands to send an update event and a delete event to a relation based channel The insert command is equivalent to the send command Also you can check the current registered statements in a session with the statement command and find out the channels you have created in a session with the channels command The eventtypes commands enables you to display the structure of all event types in the server For more information about Oracle CQL processor queries see Oracle CQL Processors 14 3 2 Management Commands Management commands enable you to list the deployed Oracle Stream Explorer applications list libraries install an application send events to an existing application subscribe to channel events list all public stages retrieve an OSGi service and call stan
54. create a class that implements com bea cache jcache CacheLoader interface This interface includes the load method to customize loading a single object into the cache Oracle Stream Explorer calls this method when the requested object is not in the cache The interface also includes 1oadA11 methods that you implement to customize the loading of the entire cache In Example 8 1 the local Loader bean loads events into an Oracle Coherence cache when the backing store is read only When working with a Coherence cache note that if you specify a cache loader in your configuration file you must also specify the corresponding class factory method name in your Coherence cache configuration file For a cache loader you specify the get Loader method of com bea wlevs cache coherence configuration SpringFactory For example code see Configure an Oracle Coherence Caching System and Cache Example 8 1 Oracle Coherence Cache EPN Assembly File for a Cache Loader lt wlevs caching system id caching system id gt lt wlevs cache id myCache advertise false gt lt wlevs caching system ref caching system id gt lt wlevs cache loader ref localLoader gt lt wlevs cache gt lt bean id localLoader class com bea wlevs example provider coherence LocalLoader gt Example 8 2 Oracle Coherence Cache LocalLoader Implementation package com bea wlevs example provider coherence import java util Collection import java util HashMap import j
55. e seconds wait the specified number of seconds e minutes wait the specified number of minutes Default units is seconds High Availability Applications 17 37 Configure High Availability Adapters 17 10 3 Configure the Broadcast Output Adapter The Oracle Stream Explorer high availability broadcast output adapter is implemented by the GroupBroadcast QueveTrimmingAdapter class Assembly File The root element to declare an Oracle Stream Explorer high availability broadcast output adapter is wlevs adapter with the provider element set to ha broadcast as shown lt wlevs adapter id myBroadcastAdapter provider ha broadcast gt lt wlevs listener ref actualAdapter gt lt wlevs instance property name keyProperties value time gt lt wlevs instance property name monotonic value true gt lt wlevs adapter gt Table 17 9 describes the additional child elements Table 17 9 Child Elements Child Element Description wlevs listener Specify the regular output adapter downstream from this Oracle Stream Explorer high availability broadcast output adapter wlevs instance Specify one or more instance property element name and property value attributes as Table 17 10 describes Table 17 10 lists the instance properties Table 17 10 Instance Properties Name Value keyProperties Specify a space delimited list of one or more event properties that the Oracle Stream Explorer high availability broadc
56. ena Ea eaaa 1 1 1 2 Component Configuration sisie seo eE E EEE EEE E i a E aa 1 2 1 3 Streams and Relati NS enire an e E ERE EEEE E E E aa 1 4 1 4 Application Scalability and High Availability cececeseecetenesesesesneenesescenesseeeeenenes 1 5 15 Application Lite Cy cle seiere tet E E cna vesesanstanasves eats E E E 1 5 Lon APLOVerview sitiens eaae E E AEE thie Doan oa iat naitas E 1 7 db 7 Spring PramMew Ork iiris isiin raakh teeth eaae Vea AEE EEEa KRE A DAE EE PAEA R EE EE EE E A EEEE EES ett 1 12 TS OSGi Service Plator iSite erae ie pae iea AEAEE a AETAT PREEK AEE AEAEE ASEE EEE EEEa 1 12 Application and Resource Configuration 2 1 Application Configurations iga o eE E a 2 1 22 Assembly File Structure nsession iee a EEE aE ET EEE EE a a 2 2 2 2 1 Nested Stages in an EPN Assembly File cccccscsccscsessesesessesesesceceenescsnansnessseseeneseseeeees 2 3 2 2 2 Foreign Stages in an EPN Assembly File c cccscscccsessetesesceseseseeceesesesesnseseseseeneneaeseees 2 4 2 3 Component Configuration File Structure cccceccscescscssenenesesesneneesescecesesesesnensnesessseeeneseeeees 2 5 2 4 Component and Server Configuration ccccccsccccsescscesesssessensesesesneneesescecesesesssnensnesessseeeneseeeees 2 5 2 5 Resource Access Configuration issie Erni pa e iee eE e AERE DE EEEE KEA EE 2 6 2 5 1 Resource Access Annotations sseeseesseesseesertesstssessertesstsesstettsstsntentettsesseeneetestsneeneenent 2 7 2 5
57. event type gt MyConfigEvent lt event type gt lt default session description default configuration gt lt configuration description identifier message format gt lt config name gt BeginString lt config name gt lt config value gt FIXT 0 1 lt config value gt lt configuration gt lt default session gt lt session description ordertracker configuration gt lt configuration description identifier acceptor gt lt config name gt SenderCompID lt config name gt lt config value gt QA lt config value gt lt configuration gt lt configuration description identifier initiator gt lt config name gt TargetCompID lt config name gt lt config value gt ORACLE lt config value gt lt configuration gt lt session gt lt quickfix adapter gt 4 13 3 Configure a Socket Based Acceptor Failover You can configure a simple failover scheme for socket based acceptors by running two acceptor processes with a shared MessageStore One process is the active acceptor and the other process is the standby for any session When one acceptor process dies 4 20 Developing Applications for Event Processing with Oracle Stream Explorer REST Adapter the client having been configured with failover addresses attempts to log on to the other acceptor Upon successful logon the message store for that session refreshes and the failover session continues normally The following configuration settings are required for a successful failove
58. field you want to do range controlling ocep binding Parameters gt lt Option label remainingQty value remainingQty gt lt Option label totalQty value totalQty gt lt Option label price value price gt lt AD gt lt OCD gt lt Designate pid productProcessor productRule gt lt Object ocdref com oracle cep solution product filter gt lt Designate gt Adda processor element to the config xml file that defines the productProcessor as follows Note that the ADs definitions correspond to query parameters 1 and 2 in the sequence lt processor gt lt name gt productProcessor lt name gt lt rules gt lt query id productRule gt lt CDATA IStream select FROM productInputChannel RANGE 1 on 2 gt lt query gt lt rules gt lt processor gt 11 7 Deploy the HelloWorld Application The following example uses the EPN shell with Apache Felix Gogo to deploy the parameterized HellowWorld application The EPN shell interfaces with OSGi Bundle Repository OBR and uses introspection to locate the available metadata and to form the applicable prompts to the user The following example shows the HelloWorld application output when it is deployed with the EPN shell Note Parametrized applications are not supported on a clustered domain Also you can deploy only through the EPN shell For this release parameterized application deployment is not supported in Oracle JDeveloper or in Oracle
59. generate exactly the same sequence of output events as existing secondaries all tuple based windows must be qualified by time See Choose an Adequate warm up window length Time 17 8 3 3 Partitioned Windows Avoid partitioned windows because there are situations in which a partition cannot be rebuilt If you do use partitioned windows configure a warm up window length time long enough to give the Oracle Stream Explorer server time to rebuild the partition See Choose an Adequate warm up window length Time 17 8 3 4 Sliding Windows Oracle CQL queries should not use sliding windows when new stages that join the multiserver domain are expected to generate exactly the same output events as existing stages See Rejoining the High Availability MultiServer Domain 17 8 3 5 DURATION Clause and Non Event Detection You must use application time when Oracle CQL queries contain a DURATION clause for non event detection See Prefer Application Time 17 8 3 6 Prefer Application Time In Oracle Stream Explorer each event is associated with a point in time at which the event occurred Oracle CQL recognizes two types of time e Application time A time value assigned to each event outside of Oracle CQL by the application before the event enters the Oracle CQL processor e System time A time value associated with an event when it arrives at the Oracle CQL processor essentially by calling System nanoTime Application time is generally the best
60. gt CallCenterActivity lt event type name gt lt metadata gt external_metadata_casel xml lt metadata gt lt jaxb mapper gt lt json mapper gt lt name gt jsonMapperBean lt name gt lt event type name gt CallCenterActivity lt event type name gt lt media type gt application json lt media type gt lt json mapper gt The following configuration file shows the settings for an outbound REST adapter that unmarshalls an event to the XML or JSON content types lt rest adapter gt lt name gt restXmlOutbound lt name gt lt url gt http localhost 9002 testrestadapter lt url gt lt rest adapter gt lt rest adapter gt lt name gt rest JsonOutbound lt name gt lt url gt http localhost 9002 testrestadapter lt url gt lt rest adapter gt lt jaxb mapper gt lt name gt xmlMapperBean lt name gt lt event type name gt CallCenterActivity lt event type name gt lt metadata gt external_metadata_casel xml lt metadata gt lt jaxb mapper gt lt json mapper gt lt name gt jsonMapperBean lt name gt lt event type name gt CallCenterActivity lt event type name gt lt media type gt application json lt media type gt lt json mapper gt Note To support XML content type in the REST inbound and outbound adapters use the XML Mapper Adding XML annotations or generating JAXB bindings file automatically is not supported in this release 4 15 RMI Adapters Use the RMI Inbound and Outbound adapters to read even
61. in a single server domain without high availability In this case the simplest scenario which is an Oracle Stream Explorer application running on one Oracle Stream Explorer server processes an input event stream and produces output events 17 8 Developing Applications for Event Processing with Oracle Stream Explorer Choose a Quality of Service Option High availability scenario The application is configured to use Oracle Stream Explorer high availability options is deployed to the deployment group of a multiserver domain composed of two server and only the primary server outputs events High availability and scalability scenario The high availability application is configured to use the Act iveAct iveGroupBean to define notification groups Each notification group contains two or more servers that function as a single high availability unit In this scenario only the primary server in each notification group outputs events Should the primary server in a notification group go down an Oracle Stream Explorer high availability fail over occurs and a secondary server in that notification group is declared the new primary and resumes outputting events according to the Oracle Stream Explorer high availability quality of service you configure For more information see Configure Partitioning with High Availability 17 7 Choose a Quality of Service Option You can choose any of the quality of service options that Table 17 1 lists Choose
62. jdbc write connections min value 1 gt lt property name javax persistence jdbc driver value org apache derby jdbc EmbeddedDriver gt lt property name javax persistence jdbc url value jdbc derby test1 create true gt lt property name eclipselink ddl generation value create tables gt lt property name eclipselink ddl generation output mode value database gt lt lt property name eclipselink logging timestamp value false gt lt property name eclipselink logging thread value false gt lt property name eclipselink logging session value false gt lt property name eclipselink logging exceptions value false gt lt property name eclipselink logging connection value false gt lt property name eclipselink logging level value FINER gt gt lt properties gt lt persistence unit gt lt persistence gt 9 3 2 Classes The example is comprised of the following classes e CoherenceMapListenerjava e PriceTargetjava e PriceTargetLoader java e SaleEventjava 9 6 Developing Applications for Event Processing with Oracle Stream Explorer JPA Coherence Example e SaleEventsGenerator java In this example an initial set of items go on sale and the requested target prices are set up in a data store The data store is available in the PriceTarget java Coherence cache because it is set up to be used with CacheLoader A stream of SaleEvents is generated from the SaleEvent
63. listen on for client connection test port 9001 server host test host do not change the packetType localhost if not specified test packetType CSV Table 14 1 Load Generator Properties Property Description Data Required Type test csvDataFi Specifies the file that contains the data feed String Yes le values test port The port number to which the load generator Integer Yes sends the data feed Each input adapter must be associated with its own test port test secs Total duration of the load generator run in Integer No seconds The default value is 30 test rate Final data rate in messages per second Integer No The default value is 1 test startRate Initial data rate in messages per second Integer No The default value is 1 test rampUpSec Number of seconds to ramp up from Integer No test startRatetotest rate The default value is 0 14 1 2 Create the Data Feed File A load generator data feed file contains the sample data feed values that correspond to the event type registered for your Oracle Stream Explorer application The following example show an EmployeeEvent and a load generator data feed file corresponding to this event type 14 2 Developing Applications for Event Processing with Oracle Stream Explorer Load Generator and the csvgen Adapter lt wlevs event type repository gt lt wlevs event type type name EmployeeEvent gt lt wlevs properties gt lt wlevs
64. lt CDATA select cusip bid srcId bidQty ask askQty seq from priceStream where sector 3_YEAR gt lt query gt lt query id Yr2Sector gt lt CDATA select cusip bid srcId bidQty ask askQty seq from priceStream where sector 2_YEAR gt lt query gt Channels 5 3 Batch Processing Channels lt query id YrlSector gt lt CDATA select cusip bid srcId bidQty ask askQty seq from priceStream where sector 1_YEAR gt lt query gt lt rules gt lt processor gt If you specify more than one query for an Oracle CQL processor then by default all query results are output to the Oracle CQL processor outbound channel filteredStream in Figure 5 1 Optionally in the component configuration source you can use the channel element selector child element to specify a space delimited list of one or more Oracle CQL query names that can output their results to the channel In the following example query results for query Yr3Sector and Yr2Sector are output to filteredStream but not query results for query Yr1Sector lt channel gt lt name gt filteredStream lt name gt lt selector gt Yr3Sector Yr2Sector lt selector gt lt channel gt You can configure a channel element with a selector before you create the queries in the upstream Oracle CQL processor In this case you must specify query names that match the names in the selector Note The selector child element is only applicable if the upst
65. lt wlevs instance property name mapper ref xmlMapperBean gt lt wlevs instance property name csvMapper ref csvMapperBean gt lt wlevs instance property name eventTypeName value CallCenterActivity gt lt wlevs instance property name contextPath value testhttpadapter gt lt wlevs adapter gt The following assembly file shows the settings for an outbound REST adapter that unmarshalls an event to the XML or JSON content types lt wlevs adapter id restXmlOutbound provider rest outbound gt lt wlevs instance property name mapper ref xmlMapperBean gt lt wlevs instance property name url value http localhost 9002 testadapter gt lt wlevs adapter gt lt wlevs adapter id restJsonOutbound provider rest outbound gt lt wlevs instance property name mapper ref jsonMapperBean gt lt wlevs instance property name url value http localhost 9002 testadapter gt lt wlevs adapter gt Adapters 4 21 RMI Adapters Configuration File The following configuration file shows the rest adapter configuration for receiving POST data and the jaxb mapper configuration for handling incoming XML and JSON data lt rest adapter gt lt name gt rest Inbound lt name gt lt event type name gt CallCenterActivity lt event type name gt lt context path gt testhttpadapter lt context path gt lt rest adapter gt lt jaxb mapper gt lt name gt xmlMapperBean lt name gt lt event type name
66. message text of type DateFormat which is used by the generateHelloMessag method to create events of type HelloWorldEvent The Oracle Stream Explorer framework calls the setEvent Sender method to initialize the event Sender private variable with a St reamSender instance The StreamSender instance sends events emitted by a St reamSource instance toa StreamS ink listener In this example the St reamSink listener is the HellowWorldBean instance package com bea wlevs adapter example helloworld import java text DateFormat import java util Date import com bea wlevs ede api RunnableBean import com bea wlevs ede api StreamSender import com bea wlevs ede api StreamSource import com bea wlevs event example helloworld HelloWorldEvent public class HelloWorldAdapter implements RunnableBean StreamSource private static final int SLEEP_MILLIS 300 private DateFormat dateFormat private String message private boolean suspended private StreamSender eventSender public HelloWorldAdapter super dateFormat DateFormat getTimelInstance public void run suspended false while isSuspended Generate messages forever generateHelloMessage try synchronized this wait SLEEP_MILLIS catch InterruptedException e e printStackTrace public void setMessage String message this message message private void generateHelloMessage String message this message dateFormat for
67. modules b jar e modules 0 my jar starts before module my jar because 0 my jar comes before my jar in lexical order This convention enables you to control the order in which the Oracle Stream Explorer server deploys JAR files by organizing JAR files into appropriately named subdirectories of either the library extensions directory or library directory As soon as the application deploys the Oracle Stream Explorer server creates an application configuration history and the configured adapters start to listen for events 13 5 Configuration History Configuration changes that you make to Oracle CQL rules or to the Oracle Stream Explorer high availability adapter configuration are recorded in the history You can view and roll back undo these changes with the Oracle Stream Explorer Visualizer or wlevs Admin command line tool You can export the change history to a file and use that file to update your application source with changes made at runtime For more information see e Using Visualizer for Oracle Stream Explorer e Administering Oracle Stream Explorer 13 6 Assemble an OSGi Bundle with appC The appC utility is a command line tool that enables you to build validate and compile an application You can create or modify the various files that comprise an Oracle Stream Explorer project The appC tool validates against the following schema versions spring wlevs v12_1_3_0 xsdand spring beans xsdand spring osgi xsd You
68. myHaSlidingWindowAdapter gt lt wlevs source ref helloworldProcessor gt lt wlevs channel gt lt wlevs adapter id myHaSlidingWindowAdapter provider ha buffering gt lt wlevs listener gt lt bean class com bea wlevs example helloworld HelloWorldBean gt lt wlevs listener gt lt wlevs adapter gt 5 Optionally configure the channel downstream from the input adapter helloworldInputChannel to configure an application time stamp based on an appropriate event property as shown For simple failover with buffering you can use system time stamps because events are not correlated between servers However it is possible that slightly different results might be output from the buffer if application time stamps are not used In this example event property arrivalTime is used The wlevs expression should be set to this event property lt wlevs channel id helloworldInputChannel event type HelloWorldEvent gt lt wlevs listener ref helloworldProcessor gt lt wlevs source ref myHaInputAdapter gt lt wlevs application timestamped gt lt wlevs expression gt arrivalTime lt wlevs expression gt lt wlevs application timestamped gt lt wlevs channel gt 6 Configure the Oracle Stream Explorer high availability buffering output adapter Set the instance property windowLength to a value greater than zero 0 as shown 17 22 Developing Applications for Event Processing with Oracle Stream Explorer Conf
69. named MyDeployment Group See Administering Oracle Stream Explorer Configure the Oracle Stream Explorer server configuration file on each Oracle Stream Explorer server to add the appropriate Act iveAct iveGroupBean notification group to the groups child element of the cluster element The Oracle Stream Explorer server configuration file is located in Oracle Middleware my_oep user_projects domains lt domain_name gt lt server_name gt config Table 18 2 shows cluster elements for Oracle Stream Explorer servers ocep server 1 ocep server 2 ocep server 3 and ocep server 4 The deployment group is MyDeploymentGroup and notification groups are defined using default Act iveAct iveGroupBean notification group names Note that ocep server 1 and ocep server 2 use the same notification group name ActiveActiveGroupBean_group1 and ocep server 3 and ocep Scalable Applications 18 7 Partition an Incoming JMS Event Stream server 4 use the same notification group name ActiveActiveGroupBean_group2 Table 18 2 Server Configuration File Groups Element Configuration Partition cluster Element ocep lt cluster gt server l lt server name gt ocep server 1 lt server name gt lt enabled gt coherence lt enabled gt lt groups gt MyDeploymentGroup ActiveActiveGroupBean_groupl lt groups gt lt cluster gt ocep lt cluster gt server 2 lt server name gt ocep server 2 lt server name gt lt enable
70. no class files or properties file being created il8ngen exits with a bad exit status nobuild Parse and validate only debug Debugging mode dates Causes weblogic il8ngen to update message time stamps in the catalog If the catalog is writable and time stamps have been updated the catalog is rewritten filelist Process the files and directories in this list of files If directories are listed the command processes all XML files in the listed directories The names of all files must include an XML suffix All files must conform to the msgcat dtd syntax weblogic il8ngen prints the fully qualified list of names Java source to the stdout log for those files actually generated Create locale specific catalogs as needed for the message catalog you created in Step 1 Run weblogic 110ngen to process the locale specific catalogs you created in Step 3 Code your application to use the Logger or TextFormatter classes you generated in Step 2 Use the OSGi import statements in the application MANIFEST MF file to import the following packages into your Oracle Stream Explorer application weblogic 1i18n logging weblogic logging When your application calls one of the Logger or Text Formatter methods to log or return a message the method writes the localized version of the message text to the target location A Logger method writes the localized version of the message to the localized log files and a Text Formatter method write
71. of this instance property is the name of the event property by which the channel partitions events In this example the channel partitions events by the event property symbol lt wlevs event type repository gt lt wlevs event type type name PriceEvent gt lt wlevs properties gt lt wlevs property name symbol type char gt lt wlevs property name price type long gt lt wlevs properties gt lt wlevs event type gt lt wlevs event type repository gt lt wlevs channel id EventPartitionerChannel event type PriceEvent gt lt wlevs instance property name partitionByEventProperty value symbol gt lt wlevs listener ref processor1i gt lt wlevs listener ref processor2 gt lt wlevs listener ref processor3 gt lt wlevs source ref inbound gt lt wlevs channel gt 18 1 2 Configure Parallel Processing on the Channel If you want the channel to allocate threads set the max threads property to the number of listeners in the EPN If you want to provide increased concurrency downstream from the channel you can associate a thread pool with the channel by setting the max threads property on the channel The best value for the maximum number of threads can depend on many factors including the details of the Oracle CQL queries in downstream processors do the queries allow parallel execution and the behavior observed while running the application are all the CPU cores utilized As a starting poi
72. orderID this orderID orderID public int getAccountID return accountID public setOrderID int accountID this accountID accountID public int hashCode int hash 1 ash hash 31 orderID hashCode ash hash 31 accountID null 0 accountID hashCode High Availability Applications 17 31 Configure High Availability Quality of Service return hash public boolean equals Object obj if obj this return true if obj null return false if obj instanceof MyCompoundKeyClass return false MyCompoundKeyClass k MyCompoundKeyClass obj return k accountID accountID amp amp k orderID orderID 7 Configure the channel downstream from the high availability input adapter channe11 to configure an application time stamp based on the high availability input adapter timeProperty setting as the following example shows The wlevs expression should be set to the timeProperty value lt wlevs adapter id myHaInputAdapter provider ha inbound gt lt wlevs instance property name eventType value HelloWorldEvent gt lt wlevs instance property name keyProperties value sequenceNo gt lt wlevs instance property name timeProperty value inboundTime gt lt wlevs adapter gt lt wlevs channel id channell event type StockTick gt lt wlevs listener ref processorl gt lt wlevs source ref myHaInputAdapter gt lt wlevs application
73. patterns defined by java text MessageFormat Arguments are values that can be dynamically set at runtime These values are passed to routines such as a routine for printing a message A message can support up to 10 arguments numbered 0 9 You can include any subset of these arguments in any text section of the message definition message body message detail probable cause although the message body must include all of the arguments e Only the message body section in a simple text message can include arguments e You must assign a severity level for log messages Log messages are generated through the generated Logger methods as defined by the method attribute You insert message arguments into a message definition during development and these arguments are replaced by the appropriate message content at runtime when the message is logged e Arguments are type St ring or representable as a St ring type e Numeric data is represented as n number e Dates are supported as n date The following excerpt from an XML log message definition shows how to use message arguments The argument number must correspond to one of the arguments specified in the method attribute Specifically 0 with the first argument 1 with the second and so on In the following example 0 represents the file that cannot be opened while 1 represents the file that is opened in its place lt messagebody gt Unable to open file 0 Opening 1 All
74. property name name type char gt lt wlevs property name age type int gt lt wlevs property name birthplace type char length 512 gt lt wlevs properties gt lt wlevs event type gt lt wlevs event type repository gt Lucy 23 Madagascar Nick 44 Canada Amanda 12 Malaysia Juliet 43 Spain Horatio 80 Argentina A load generator data feed file follows a simple format Put each data feed item is on its own line e Separate the fields of a data feed item with commas e Do not include commas in a string field e Do not include extraneous spaces before or after the commas unless the space is literally part of the field value e Include only string and numerical data in a data feed file such as integer long double and float e Keep within the maximum string length of 256 characters or specify a long string length To specify a longer string set the Length attribute of the char property in your event type for the birthplace property Note The load generator does not fully comply with the CSV specification at http www creativyst com Doc Articles CSV CSV01 htm For more information about CSV adapter constraints see Design Constraints 14 1 3 Configure the csvgen Adapter in Your Application When using the load generator utility you must use the csvgen adapter in your application because this Oracle Stream Explorer provided adapter is specifically coded to read the data packets generated by t
75. property name time_stamp type timestamp gt lt wlevs properties gt lt wlevs event type gt lt wlevs event type repository gt 3 6 Developing Applications for Event Processing with Oracle Stream Explorer Interval and Time Stamp Properties 3 6 Interval and Time Stamp Properties Event types also support the day to second and year to month interval properties and the time stamp with local time zone properties 3 6 1 Interval Properties The following assembly file entries show the interval properties lt wlevs event type repository gt lt wlevs event type type name IntervalDataTypeEvent gt lt wlevs properties gt lt wlevs property name Comment type char length 256 gt lt wlevs property name intervalProp type interval day 1 to second 2 gt lt wlevs property name intervalymProp type interval year 2 to month gt lt wlevs property name intervaldhProp type interval day to hour gt lt wlevs property name intervaldmProp type interval day to minute gt lt wlevs property name intervalhsProp type interval hour 1 to second 2 gt lt wlevs property name intervalhmProp type interval hour to minute gt lt wlevs property name intervalmsProp type interval minute 2 to second 2 gt lt wlevs property name intervaldProp type interval day 1 gt lt wlevs property name intervalyProp type interval year 2 gt lt wlevs property name intervalmProp type interval month
76. sGenerator adapter If the sale prices match the target prices they are stored in SaleEvent Coherence cache A Coherence MapListener implementation verifies that the SaleEvents stored in the cache are actually available in the data store as well 9 3 2 1 CoherenceMapListener java The CoherenceMapListener java class listens for events published to the coherence cache package com oracle cep sample import java util List import javax persistence EntityManager import javax persistence EntityManagerFactory import javax persistence Persistence import javax persistence Query import org springframework beans factory DisposableBean import com tangosol util MapListener import com tangosol util MapEvent import com tangosol util ObservableMap import com bea wlevs ede api InitializingBean import com bea wlevs ede api StreamSource import com bea wlevs ede api StreamSender public class CoherenceMapListener implements MapListener InitializingBean StreamSource private static final String PERSISTENCE_UNIT_NAME derby private EntityManagerFactory m_entityMgrFactory private EntityManager m_entityMgr private ObservableMap m_saleEventCache private StreamSender m_sender public void afterPropertiesSet m_saleEventCache addMapListener this public void setEventSender StreamSender sender m_sender sender public void setSaleEventCache ObservableMap cache m_saleEventCache cache public v
77. sections e Create Adapters e Cluster Distribution Service e Password Encryption e JAXB Support e CSV Adapters e EDN Adapters e File Adapter e HTTP Publish Subscribe Adapter e HTTP Publish Subscribe Adapter Custom Converter Bean e JMS Adapters e JMS Custom Message Converter Bean e Oracle Business Rules Adapter e QuickFix Adapter e REST Adapter e RMI Adapters For information about the high availability adapters see High Availability Applications See Testing 1 2 3 for information about how to use the csvgen adapter with the load generator to simulate a data feed to test your application Adapters 4 1 Create Adapters 4 1 Create Adapters The best way to create most adapters is with Oracle JDeveloper The Oracle JDeveloper components window provides the following inbound and outbound adapters CSV EDN RMI HTTP and JMS For the other adapters edit the configuration files directly Each adapter section in this chapter provides example assembly and configuration file configurations so that you can see the settings Before you create an adapter use Oracle JDeveloper to create an event type to assign to the adapter See Getting Started with Event Processing for Oracle Stream Explorer for information about creating adapters event types and other components in Oracle JDeveloper This chapter describes some of the assembly and configuration file settings for the different types of adapters For complete informat
78. sh Bundle Description OCEP example helloworld Bundle SymbolicName helloworld 13 7 3 Include Third Party JAR Files When you create your Oracle Stream Explorer applications you might need to access legacy libraries within existing third party JAR files You can ensure access to this legacy code with any of the following approaches e Bundle Classpath e Operating System Path e Xbootclasspath Bundle Classpath The recommended approach is to package the third party JAR files in your Oracle Stream Explorer application JAR file You can put the JAR files anywhere you want Note This approach gives you little control over the order in which JAR files are loaded and it is possible that dependency conflicts may occur For this reason Oracle recommends that you use the Oracle Stream Explorer server application library approach instead To ensure that your Oracle Stream Explorer application finds the classes in the third party JAR file you must update the application class path by adding the Bundle Classpath header to the MANIFEST MF file Set Bundle Classpath to a comma separate list of the JAR file path names that should be searched for classes and resources Use a period to specify the bundle itself For example Bundle Classpath commons logging jar myExcitingJar jar myOtherExcitingJar jar If you need to access native libraries you must also package them in your JAR file and use the Bundle Nat iveCode header
79. sink an event source or both An event sink receives and works on large quantities of event data An event source sends large quantities of event data In an EPN you can configure event beans and adapters with logic to make them behave as event sources event sinks or both In the case of an event bean the event sink and event source logic comes from its associated JavaBean In the case of an adapter the event sink and event source logic comes from its JavaBean event type See Events and Event Types for information about creating a JavaBean event type You can use JAXB in event bean logic See JAXB Support for information This chapter includes the following sections e Event Beans and Spring Beans e Event Sink Interfaces e Event Source Interfaces 7 1 Event Beans and Spring Beans Event beans and Spring beans are based on Java classes The Java class you use for an event or Spring bean can conform to the JavaBean specification or not conform depending on your application requirements An event bean is an Oracle extension to the regular Spring based bean An event bean can be an event sink event source or both an event sink and an event source You can add event sinks and sources to adapters and event beans e Anevent sink is a JavaBean or Java class that listens for and works on events An event sink can receive events retrieve data from the events and create a new event from the data to send to a downstream component e An ev
80. state names STARTING INITIALIZING RUNNING SUSPENDING SUSPENDED and FAILED correspond to the ApplicationRuntimeMBean method get State return values These states are specific to Oracle Stream Explorer They are not OSGi bundle states Figure 1 1 Oracle Stream Explorer Application Life Cycle State Diagram Start Server With Deployed Application G Deploy Application M M lt Starting lt lt Initializing Resume licati Running Application Error Uninstall Suspend Application l Application lt Suspending H Unregister ApplicationRuntimeMBean amp and Uninstall Completed L gt Failed Note For information on Oracle Stream Explorer server life cycle see Administering Oracle Stream Explorer Introduction to Application Development 1 5 Application Life Cycle This section describes the life cycle of an application deployed to the Oracle Stream Explorer server and the sequence of com bea wlevs ede api API callbacks The information explains how Oracle Stream Explorer manages an application s life cycle so that you can better use the life cycle APIs in your application For a description of these life cycle APIs such as RunnableBean and SuspendableBean see e API Overview e Java API Reference for Oracle Stream Explorer The life cycle description is broken down into actions that a user performs including those described in the follow
81. that is appropriate for the given event type A channel can represent either a stream or a relation A stream or relation channel inserts events into a collection and sends the resulting stream to the next EPN stage Events in a stream can never be deleted from the stream Events in a relation can be inserted into deleted from and updated in the relation For insert delete and update operations events in a relation must always be referenced to a particular point in time See Streams and Relations for more information 1 2 Developing Applications for Event Processing with Oracle Stream Explorer Component Configuration Oracle CQL Processors You configure Oracle CQL processors with Oracle CQL query code to examine events as they pass through The Oracle JDeveloper Components window provides CQL Patterns to facilitate the formation of Oracle CQL queries The wizard for each CQL Pattern prompts you for the correct configuration data to ensure that you form a valid Oracle CQL query Beans A bean defines application event logic written in the Java programming language that conforms to standard Spring based beans An event bean is a Java class that implements logic to listen for and work on events This type of Java class is called a listener Java class A listener that receives events event sink might create new events when it finds a certain type of data and send the new events to the next stage for further processing A listener even
82. the key The value of the key class attribute must be a JavaBean class with public fields that match the fields of the event class The JavaBean class must override the equals and hashCode methods from the java lang Object class The matching is done according to the field name For example lt wlevs cache id myCache key class key class name gt lt wlevs caching system ref caching system id gt lt wlevs cache gt For a cache with a composite key composed of key field1 and key field2 you can execute both of the following queries SELECT stream field2 cache key fieldl from stream NOW cache WHERE stream field2 cache key fieldl AND stream field2 cache key field2 SELECT stream fieldl cache key fieldl from stream NOW cache WHERE stream fieldl cache key fieldl 8 6 Configure a Cache as an Event Source You can configure a cache as an event source To use a cache as an event source you need to implement the com bea wlevs ede api StreamSink interface The configuration follows lt wlevs cache id cache id name alternative cache name caching system caching system id gt lt wlevs listener ref cache listener id gt lt wlevs cache gt Cached Event Data 8 11 Configure a Cache with a Cache Listener 8 7 Configure a Cache with a Cache Listener You can configure a cache as a source of events to which another component in the event processing network listens The listening component can be an adapter or a bea
83. the wlevs cache element Oracle Stream Explorer automatically injects the cache implemented as a java util Map into the adapter In the adapter Java source add a setMap Map method with the code that implements whatever you want the adapter to do with the cache package com bea wlevs example import java util Map public class MyAdapter implements Runnable Adapter EventSource SuspendableBean public void setMap Map map 8 10 3 Access a Cache From a Business POJO A business POJO configured as a standard Spring bean in the EPN assembly file can be injected with a cache using the standard Spring mechanism for referencing another bean In this way the POJO can view and manipulate the cache A cache bean implements the java util Map interface which is what the business POJO uses to access the injected cache A cache bean can also implement a vendor specific sub interface of java util Map but for portability it is recommended that you implement Map First the configuration of the business POJO in the EPN assembly file must be updated with a property child element as shown in the following example based on the Output bean of the FX example see Getting Started with Event Processing for Oracle Stream Explorer lt wlevs caching system id caching system id gt lt wlevs cache id cache id name alternative cache name gt lt wlevs caching system ref caching system id gt lt wlevs cache gt lt bean class
84. think of long term state as something kept in stable storage such as a distributed cache or a database to leverage the high availability facilities of these technologies 17 8 2 5 Choose an Adequate warm up window length Time When a new Oracle Stream Explorer server is added to a high availability multiserver domain or when an existing failed server restarts the server does not fully join the Oracle Stream Explorer high availability deployment and notification groups until all applications deployed to it have fully joined The type of application determines when it fully joins Oracle Stream Explorer high availability applications can be described as Type 1 or Type 2 applications as Table 17 2 shows Table 17 2 Oracle Stream Explorer High Availability Application Types Application Must generate exactly Must be able to rebuild Must wait this period of Type the same sequence of internal state by time before it has fully output events processing input joined streams within a finite period of time Type 1 Yes Yes Yes Type 2 No No No For more information see Rejoining the High Availability MultiServer Domain 17 8 2 5 1 Type 1 Applications A Type 1 application requires the new secondary server to generate exactly the same sequence of output events as existing secondary servers once it fully joins the high availability deployment and notification groups A Type 1 application must be able to rebuild its internal state by p
85. this lt wlevs channel id channell event type StockTick gt lt wlevs listener ref processor gt lt wlevs channel gt lt wlevs processor id processor gt lt wlevs listener ref Cchannel2 gt lt wlevs processor gt lt wlevs channel id channel2 event type StockTick gt lt wlevs listener ref cache id gt lt wlevs channel gt SELECT Sl symbol Sl lastPrice stockCache description FROM S1 Now stockCache WHERE Sl symbol stockCache symbol 8 10 2 Access a Cache from an Adapter An adapter can also be injected with a cache using the standard Spring mechanism for referencing another bean A cache bean implements the java util Map interface which is what the adapter uses to access the injected cache First the configuration of the adapter in the EPN assembly file must be updated with a wlevs instance property child element as shown in the following example lt wlevs caching system id caching system id gt lt wlevs cache id cache id name alternative cache name gt lt wlevs caching system ref caching system id gt lt wlevs cache gt lt wlevs adapter id myAdapter provider myProvider gt lt wlevs instance property name map ref cache id gt lt wlevs adapter gt 8 20 Developing Applications for Event Processing with Oracle Stream Explorer Access a Cache from Application Code In the example the ref attribute of wlevs instance property references the id value of
86. time in nanoseconds to events as they arrive at the adapter and forwards the time values assigned for each event to all secondary servers Because a time value is assigned to each event before the event reaches any downstream channels in the EPN downstream channels should be configured to use application time so that they do not assign a new time value to events as they arrive at the channel Input events must have a key that uniquely identifies each event in order to use this adapter 17 6 Developing Applications for Event Processing with Oracle Stream Explorer High Availability Adapters You can configure the Oracle Stream Explorer high availability input adapter to send heartbeat events The Oracle Stream Explorer high availability input adapter is applicable to all high availability quality of service options However because the high availability input adapter increases performance overhead it is not appropriate for some high availability quality of service options such as Simple Failover and Simple Failover with Buffering For these options you should instead consider using application time with some incoming event property For more information see e Light Weight Queue Trimming e Precise Recovery with JMS e Configure the High Availability Input Adapter 17 5 2 Buffering Output Adapter The Oracle Stream Explorer high availability buffering output adapter implements a buffered queue trimming strategy The buffer i
87. to relation operators are RANGE and ROW RANGE Operator You can specify a window of time with the time based window operator RANGE as follows SELECT AVG price FROM StockTradeIStreamChannel RANGE 1 MINUTE In this example and to keep the example easy to understand the range is 1 minute ticks in seconds and one input event is received every second The query starts averaging the prices contained in the events at zero seconds and outputs a value of 0 because there is no event in the relation at zero seconds When the next event arrives at 1 second the average price is the price in the first event When the next event arrives at 2 seconds the average price is the average of the two events in the relation This continues until 59 seconds 1 minute is reached An important concept with time based window operators is that the window shifts over the event stream based on time When 60 seconds have elapsed the window shifts by one second to average the prices in the events from 1 to 60 seconds and when 60 more seconds are reached the window shifts by one more second to average the prices in the events from 2 to 61 seconds The window shifting over the relation behavior continues as long as the application runs The following configuration file entry shows the query ISTREAM is a relation to stream operator described in Relation to Stream Operators 6 4 Developing Applications for Event Processing with Oracle Stream Explorer Que
88. used under license and are trademarks or registered trademarks of SPARC International Inc AMD Opteron the AMD logo and the AMD Opteron logo are trademarks or registered trademarks of Advanced Micro Devices UNIX is a registered trademark of The Open Group This software or hardware and documentation may provide access to or information about content products and services from third parties Oracle Corporation and its affiliates are not responsible for and expressly disclaim all warranties of any kind with respect to third party content products and services unless otherwise set forth in an applicable agreement between you and Oracle Oracle Corporation and its affiliates will not be responsible for any loss costs or damages incurred due to your access to or use of third party content products or services except as set forth in an applicable agreement between you and Oracle Contents fed oo C ee eee Pa RSE URCHIN COTE PERT AE AE RTE PAAA UOT ME eS EY TE Ee xi AULT CO AS E EESO AAEE EENE EE ESE RS EEEE EESE xi Documentation Accessibility seene a aa NAE corte ata eaS ESERE xi Related Doc N S a e a E E ed au ES SO TEELE EE ESIE ISEAN xi CONVETHONS AAA EE ES AS AEE ESE E ET SAS ROEE E xii What s New in This GUNN cdc ce cc here deseo adie Dred elena aoa and Pe aplad eto vcd caad detalles xiii Part Application Development 2 Introduction to Application Development Ted EPN Diagram iespiesti ee ae E Re ER EE a E E Leggett tat E a
89. which the CQL processor outputs events See Processor Output Control Slides e Views enable you to create an Oracle CQL statement that can be reused by other Oracle CQL queries See Views Event Type Definition The stock trade events used in the examples for this section are type StockTradeEventType with the following field and type definitions e tickerSymbol String e price Double e dailyHigh Double e dailyLow Double e closingValue Double 6 3 1 Stream Channels A stream channel inserts events into a collection and sends the stream to the next EPN stage Events in a stream flow continuously can never be deleted from the stream and have no end You can perform queries on the continuous stream of events flowing into your application A query on the input stream channel StockTradeIChannel1 to retrieve all stock trade events with the Oracle ticker symbol follows SELECT tickerSymbol FROM StockTradeIStreamChannel WHERE tickerSymbol ORCL The following configuration file entry shows the query ISTREAM is a relation to stream operator described in Relation to Stream Operators lt processor gt lt rules gt lt query id rulel lt CDATA ISTREAM SELECT tickerSymbol Oracle CQL Processors 6 3 Queries FROM StockTradeIStreamChannel WHERE tickerSymbol ORCL gt lt query gt lt rules gt lt processor gt 6 3 2 Time Based Relations Windows A relation channel inserts events into a collection
90. with the application in the META INF wlevs mappers jaxb directory Adapters 4 5 CSV Adapters Assembly File Configuration File Description Property Name Element Name metadata metadata The name of the file that contains the EclipseLink Moxy external metadate for mapping customization Package the file with the application in the Meta INF wlevs mappers jaxb directory metadataMap N A The Spring lt map gt element that contains one entry that corresponds to each component of the contextPath For each entry the key is the package name from the contextPath and the corresponding value is the name of a file that contains the EclipseLink Moxy external met adata for that package If the application uses EclipseLink Moxy specific external metadata the location of the metadata is specified by either the metadata property or the metadat aMap property The met adat aMap property is required when there is more than one package on the contextPath There is no support for specifying the met adat aMap property in a component configuration file 4 5 CSV Adapters CSV adapters handle inbound and outbound data that is separated by commas Use a CSVInbound adapter to accept data in the form of comma separated values entering the EPN and use a CSVOutbound adapter to send data in comma separated values out of the EPN You can test an Oracle Stream Explorer Application that uses CSV inbound adapters with the load generator provided
91. within those properties by using standard JavaBean style property access For example the following configuration snippet declares a Student Type event type that is implemented as a JavaBean class The school Student class is a JavaBean with an address property that is an Address JavaBean class The following query suggests how you might access values of the Address object underlying the address property This query selects student addresses whose postal code begins with 97 lt query id studentAddresses gt FOR StudentType SELECT student address FROM StudentType as student WHERE student address postalCode LIKE 97 lt query gt EventRejectedException Behavior in onInsertEvent Implementations You need to explicitly throw EventRejectedException in onInsertEvent implementations for exceptions you do not want to get dropped You can raise an EventProcessingException and it is propagated all the way to the source of the error through a CQL processor An EventRejectedException can chain exceptions from its downstream listeners in case there is more than one exception The CQL processor converts the Event Re jectedException to a soft exception See Fault Handling for more information 3 8 Create and Register a Tuple Event Type First identify the event data that the event type carries and then decide the properties the event type requires When you design your event you must restrict the properties to the data
92. you use a custom fault handler the query state is reset after a fault as if the query had been stopped and restarted In contrast the default behavior stops the query and drops all subsequent events 6 7 1 Implement a Fault Handler Class You create a fault handler class by implementing the com bea wlevs ede api FaultHandler interface After you have written the class you associate it with the stage for which it handles faults by registering it as an OSGi service For more information see Register a Fault Handler Your implementation of the handleFault method receives exceptions for the EPN stage with which the handler is associated The exception itself is either an instance of com bea wlevs ede api EventProcessingException or if there has been a JVM error an instance of java lang Error The method also receives a string array that contains the names of upstream stages or catchers to which the exception goes when your code rethrows it If there is more than one catcher in the array your rethrown exception goes to all of them There are two cases when the catchers array is empty when the exception occurs while executing a temporal query and when the exception is thrown to a channel s fault handler In these cases the fault handler executes in the context of a background thread and there is no linkage to upstream stages An exception that is rethrown from a fault handler travels through upstream EPN stages until it is either ca
93. 0 e Ensure if necessary that a bean receiving the query results is thread aware such as by using synchronized blocks For example you might need to do so if the bean s code builds a list from results received from queries executed on multiple threads 6 6 2 The ordering constraint Attribute You enable parallel query execution by relaxing the default ordering constraint that ensures that events are processed serially You do this by setting the ordering constraint attribute on a query or view element In the following example the ordering constraint attribute is set to UNORDERED so that the query will execute in parallel whenever possible lt query id myquery ordering constraint UNORDERED gt SELECT symbol FROM S WHERE price gt 10 lt query gt The ordering constraint attribute supports the following three values e ORDERED means that the order of output events as implied by the order of input events is important The CQL engine will process events serially This is the default behavior e UNORDERED means that order of the output events is not important to the consumer of the output events This gives the freedom to the CQLProcessor to process events in parallel on multiple threads When possible the query will execute in parallel on multiple threads to process the events e PARTITION_ORDERED means that you re specifying that order of output events within a partition is to be prese
94. 1 send 1 a 2 end Note In a script use double quotes to enclose a String tuple value with the send command For example send msg Enter a value Single quotes do not work in a script To execute the send event oep script when you start the server edit the last line of the startwlevs command as follows SJAVA_HOME bin java Dgosh args send event oep SJVM_ARGS SDEBUG_ARGS Dwlevs home SUSER_INSTALL_DIR Dbea home BEA_HOME jar USER_INSTALL_DIR bin wlevs jar SARGS One approach is to have a test driver script that invokes other scripts and directs their output as follows source send event oep tac test output log send event out source test delete oep tac test output log test delete out 14 3 4 EPN Variable You can set the time stamp format or turn time stamps off for an EPN session OUT_TIME FORMATTED PLAIN OFF To turn off the time stamp on output events enter the following g OUT_TIME OFF To indicate formatted time stamping h OUT_TIME FORMATTED 14 3 5 EPN Commands The EPN commands are shown and described in the following list Testing 1 2 3 14 13 EPN Shell epn begin Begins a new session for invoking EPN commands epn channel Performs different actions based on the parameters e Create a channel with a map based event type e Create a named relation channel with update keys and a Java class event type Create a named channel with a map based event t
95. 1 lt concurrent consumers gt lt jms adapter gt lt jms adapter gt lt name gt JMS InboundAdapter2 lt name gt 17 32 Developing Applications for Event Processing with Oracle Stream Explorer Configure High Availability Quality of Service 10 11 12 13 lt jndi provider url gt t3 localhost 7001 lt jndi provider url gt lt destination jndi name gt Topic2 lt destination jndi name gt lt user gt weblogic lt user gt lt password gt weblogic lt password gt lt work manager gt Jett yWorkManager lt work manager gt lt concurrent consumers gt 1 lt concurrent consumers gt lt jms adapter gt lt wlevs config gt Create a channel to function as the correlated source You must configure this channel with the second regular JMS input adapter as its source The following example shows a correlated source named clusterCorrelatingOutstream whose source is JMSTInboundAdapter2 lt wlevs adapter id JMSInboundAdapter2 provider jms inbound gt lt wlevs adapter gt lt wlevs channel id clusterCorrelatingOutstream event type StockTick advertise true gt lt wlevs source ref JMSInboundAdapter2 gt lt wlevs channel gt Configure the Oracle Stream Explorer high availability correlating output adapter with the correlatedSource The following example shows a correlating output adapter configuration where the correlatedSource is clusterCorrelatingOutstream lt wlevs adapter id myHaCorre
96. 2 Static Resource Injection c ccccccccccscseeceesescesesescecesesesescsnsnesesesseesescecessesssnsnsensseseenensaeeeees 2 7 2 5 3 Dynamic Resource Injection cccccccceseseneneseceensnenesesesseeseseseseeesesenesssseseseeessnaesesees 2 9 3 4 2 5 4 Dynamic Resource Lookup Using JNDI cccccccssssssessstetesesseneneseeeecesesssnsnensneseseseeseneseees 2 9 2 5 5 Resource Name R solution sissisodan a eiela si iini ieia 2 10 Events and Event Types g1 How Events FUNCHON deeree oee a aia E eea aa Ea aaa ei east en eiaa raK 3 1 3 2 Choose a Data Structure for the Event Type s ssssesssrssssissrtssssestissstestesstesstsntesstenttesneentesstersesn ee 3 2 3 3 Design Constraints ais a Tane a ia a A a Aaaa Eei 3 3 FJA Event Type Repository niiina eaae aeaeaie Seane gdvesesbesdladesaesssdesnadpundaseasteesesadsoutsdan 3 6 CROEN 10 015 t E E E EA EE E E 3 6 3 6 Interval and Time Stamp Properties cccccesessesescecesesescstensseseseseeesesescecesesescsnsnenessseseeeneeeseees 3 7 361 Interval Properties iier a eies eara asa e ieda e eera ea oeda Aen Sa SEEE AE eE 3 7 3 6 2 Time Stamp with Local Time Zone Properties cccccessceesesesceneesssesneneeseseeneneseeeees 3 7 3 7 Create and Register a JavaBean Event Type ccccccsssssesssesssssssesesesesssssesesssssssssesesesessesesees 3 8 EAI EEA DET e R EREE A E E E A 3 8 3 7 2 Create a JavaBean Event Type Declaratively 0 cccccesesesesesssssesesesessssseseseseesss
97. 2 in Create a JavaBean Event Type Declaratively Then for step 3 do the following To register a JavaBean event type programmatically use the Event TypeRepository class as shown EventTypeRepository rep getEventTypeRepository rep registerEventType MarketEvent com bea wlevs example algotrading event MarketEvent getClass i For more information see Access the Event Type Repository Once you create a JavBean even type you can reference it in your application Java code The following code references the MarketEvent event type in the onInsertEvent method implementation The onInsertEvent method is from an event sink class that receives events For more information on event sinks see Event Sink Interfaces public void onInsertEvent Object event throws EventRejectedException if event instanceof MarketEvent MarketEvent marketEvent MarketEvent event Events and Event Types 3 9 Create and Register a Tuple Event Type System out printlin Price marketEvent getPrice The following Oracle CQL rule shows how to reference the MarketEvent event type in a SELECT statement It assumes an upstream channel called marketEventChannel with a MarketEvent event type lt query id helloworldRule gt lt CDATA SELECT MarketEvent price FROM marketEventChannel NOW gt lt query gt Also with property data types implemented as JavaBeans Oracle CQL code can get values
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99. Availability Adapters If you need to scale your Oracle Stream Explorer high availability application use the ActiveAct iveGroupBean to define a notification group that allows two or more servers to function as a primary server unit while retaining the convenience of a single deployment group that spans all servers primaries and secondaries You must use Oracle Coherence based clustering to create the multiserver domain deployment group You can use either default groups or custom groups For more information see e High Availability and Scalability e Oracle Coherence e Administering Oracle Stream Explorer 17 5 High Availability Adapters To implement Oracle Stream Explorer high availability add the optional high availability input adapter and the required high availability output adapters to the EPN High Availability Input Adapter The optional high availability input adapter in the primary server communicates with the corresponding high availability input adapters in each secondary server to normalize event time stamps Oracle Stream Explorer high availability provides one type of high availability input adapter See High Availability Input Adapter High Availability Output Adapters To have high availability functionality in your application put a high availability output adapter before each output adapter in your EPN The high availability output adapter in the primary server outputs events to the output streams that conn
100. Channel event type HelloWorldEvent advertise true gt lt wlevs listener gt lt bean class com bea wlevs example helloworld HelloWorldBean gt lt wlevs listener gt lt wlevs source ref helloworldProcessor gt lt wlevs channel gt Alternatively you can define this EPN so that all stages are nested as Example 2 1 shows The hel loworldAdapter the outermost parent stage is the only stage accessible to other stages in the EPN Application and Resource Configuration 2 3 Assembly File Structure Example 2 1 EPN Assembly File with All Stages Nested lt wlevs adapter id helloworldAdapter class com bea wlevs adapter example helloworld HelloWorldAdapter gt lt wlevs instance property name message value HelloWorld the current time is gt lt wlevs listener gt lt wlevs channel id helloworldInputChannel event type HelloWorldEvent gt lt wlevs listener gt lt wlevs processor id helloworldProcessor gt lt wlevs listener gt lt wlevs channel id helloworldOutputChannel event type HelloWorldEvent gt lt wlevs listener gt lt bean class com bea wlevs example helloworld HelloWorl dBean gt lt wlevs listener gt lt wlevs channel gt lt wlevs listener gt lt wlevs processor gt lt wlevs listener gt lt wlevs channel gt lt wlevs listener gt lt wlevs adapter gt 2 2 2 Foreign Stages in an EPN Assembly File You can refer to a stage that is in another Oracle Stream Explorer ap
101. Configure Partitioning on the Channel ccccccccccccssesssesssneneseseenenesescecenesesssesnaneness 18 2 18 1 2 Configure Parallel Processing on the Channel cccccccsscscsessesesesceceseseecenesesesesnenenens 18 2 18 1 3 Configure Parallel Processing on the Upstream Adapter cccccccecssesesesesteteees 18 3 18 1 4 Define a Local Partition Channel ccccccccccsessessessceccecscessecseessecsecseceeceseeeseesenseesees 18 4 18 2 Partition an Incoming JMS Event Stream ccccccseesesecsesssesesescsesssesesescsesesesescseseeseeseees 18 4 18 2 1 Configure Partitioning without High Availability cece es eneneneeeees 18 4 18 2 2 Configure Partitioning with High Availability ceccsenesesescseseneeseeeee 18 6 18 3 Notification Group Naming Conventions ccccccesseseescesesesescenenesesesesneseseseeceeesesesesnensnens 18 11 18 4 Custom Channel Event Partitionerr c ccc cccssccsscesscescesseeecesseesesceeceseeseecseeeeecseesaecseesaeenees 18 12 18 4 1 EventPartitioner Interface cccccccccsccssessscsscesscescesseeceeseeceseeseceseeeeecssecsecsecsaecsueaeenses 18 12 18 4 2 Implement the EventPartitioner Interface ssesssssssesssistestertessissestestessesnesteneeseess 18 13 Audience Preface This document describes how to create deploy and debug Oracle Stream Explorer applications This document is intended for developers who want to create Oracle Stream Explorer applications Documentat
102. EA E KEETE EE 6 10 8 vi 6 6 6 7 Goo Assembly Files iiss ssstss Gosh ei is de teri See tees E EE eTe SAE EEE e s ea 6 10 6 9 2 Configuration Files sere sissies sable eet hase cite gosta cas basa to Abb Ss Doe Ee aban SEa EEAO S Sova Saas 6 10 Configure an Oracle CQL Processor for Parallel Query Execution cccccscseseseseeeseseees 6 11 6 6 1 Set Up Parallel Query Execution Support 0 0 cccscseeeseeeeeeteseecenesesesnsneneseseseeeeeseseeeenes 6 12 6 6 2 The ordering constraint Attribute 0 0 0 ccc ccecccseeteteteseseeeeeseeeecenesesesnenseneseeceeeseseeeanenes 6 12 6 6 3 Using partition order capacity with Partitioning Queries cece eeteeeeeees 6 13 6 04 LMI taHONs e a a eiceksres eases aaa Ee A anda seitoversn A a R ESERE 6 14 Fault Handini T piana een a E E deat E E A E hae REE 6 15 6 7 1 Implement a Fault Handler Class ccccccscssescsesssteseseseeceseseseecesesesescsnseneseeceeeseseseanenes 6 16 6 7 2 Register a Fault Handler hne eiea oes eaea Eases pa ea e ree e 6 17 Event Beans 7 1 7 2 7 3 Event Beans and Spring Beans cccccccsscscscesesssescsneesesescesesescecenesescsesnsnsneseseeeseseseeceneneseseananenees 7 1 Ae Threading Behavior onnies eee a cee Ea Motes aa TE Ea aE ae Bad sey E sale EAA 7 2 7 1 2 Receive Heartbeat Events N sisien Aione ia asses parae Ea aie eRe E REEE ER EERE 7 2 Filed Create BVENE BEAN mner a aon Eae E a Ea A aO Bad A EE 7 2 ZIA Created Spring Be
103. EclipseLink JPA and Oracle Coherence The Oracle Stream Explorer installation includes the EclipseLink 2 4 2 open source mapping and persistence framework to support the use of the Java Persistence API JPA in your applications JPA is the standard for object relational mapping ORM and enterprise Java persistence This chapter presents two sample Oracle Stream Explorer applications HelloWorld and JPA Coherence Sample Code that use EclipseLink and JPA to read from and write to a database The JPA Coherence Sample Code also uses a coherence cache for coordinated data updates in an environment with clustered applications and servers This chapter includes the following sections e High Level Procedure e HelloWorld Example e JPA Coherence Example 9 1 High Level Procedure Use the following high level steps to create an Oracle Stream Explorer application that includes EclipseLink 1 Create your Oracle Stream Explorer application including JPA and Oracle Coherence as needed 2 Create a persistence xml file with the correct JPA configuration This file contains the properties that control runtime operation 3 Put the persistence xml file in the META INF directory of your application 4 Bundle and deploy the application Learn more about EclipseLink at http eclipse org eclipselink Note Coherence socket exception occurs when you run CQL sample on AIX 6 1 Japanese platform To resolve this issue Add the
104. Event TextMessage message session createTextMessage Text message event getString_1 i List lt Message gt messages new ArrayList lt Message gt messages add message return messages 3 Specify the converter in your application EPN assembly file Register the converter class using a bean element Associate the converter class with the JMS adapter by adding a wlevs instance property with name set to converterBean and ref set to the id of bean The following example shows how to register and associate the converter class lt bean id myConverter class com customer MessageConverter gt lt wlevs adapter id jmsInbound provider jms inbound gt lt wlevs instance property name converterBean ref myConverter gt lt wlevs listener ref mySink gt lt wlevs adapter gt 4 11 3 Implement the Outbound JMS Adapter This example shows you how to implement the convert method for the outbound JMS adapter 1 Using the Oracle JDeveloper or your preferred IDE add a Java class to your application project 2 Implement the com bea wlevs adapters jms api OutboundMessageConverter interface The example shows a possible implementation package com customer import com bea wlevs adapters jms api InboundMessageConverter import com bea wlevs adapters jms api MessageConverterException import com bea wlevs adapters jms api OutboundMessageConverter import javax jms JMSException import javax jms M
105. It is an error to configure topic destinations for input distribution A topic configuration generates a warning log message and is ignored In addition to the adapter types listed above you can also configure an event bean to distribute all of the events it receives to all cluster members by specifying the provider for the bean to be clusterGroupDistributor as shown in the following example lt wlevs event bean id distributor bean provider clusterGroupDistributor gt lt wlevs instance property name distributionThreadsCount value 1 gt other event bean properties lt wlevs event bean gt Oracle JDeveloper does not currently provide a component for the Cluster Distribution service However you can create a Cluster Distribution service by adding entries to the assembly and configuration files for your Oracle Stream Explorer application 4 2 Developing Applications for Event Processing with Oracle Stream Explorer Password Encryption 4 3 Password Encryption Some of the adapters have user name and password child elements Oracle Stream Explorer provides the encryptMSAConfig command so that you can encrypt the file that contains the password See Administering Oracle Stream Explorer for information about how to use the encryptMSAConfig command 4 4 JAXB Support Oracle Event Processing provides a simplified interface for using Java Architecture for XML Binding JAXB mapping capabilities in adapters and event beans to m
106. JDeveloper project For more information see Access the Event Type Repository 3 5 Properties When you create an event type you add the lt wlevs properties gt and lt wlevs property gt elements to the lt wlevs event type gt element to define the event type properties Properties have name and type attributes that define the kind of information such as ticker name ticker symbol and closing price and the corresponding data type such as String String and Double For more information about the lt wlevs event type gt element see Schema Reference for Oracle Stream Explorer Assembly File The following assembly file entries show a simple event type with one event type and one property defined by the lt wlevs class gt element The properties for this event type are defined in a JavaBean class lt wlevs event type repository gt lt wlevs event type type name TradeEvent gt lt wlevs class gt tradereport TradeEvent lt wlevs class gt lt wlevs event type gt lt wlevs event type repository gt The following assembly file entries show a message count event type with properties defined by the lt wlevs properties gt element which encloses three lt wlevs property gt elements lt wlevs event type repository gt lt wlevs event type id messagecounts type name SimpleEvent gt lt wlevs properties gt lt wlevs property name msg type char gt lt wlevs property name count type long gt lt wlevs
107. L Within Oracle CQL you reference the compiled class by name and call its methods from a SELECT statement See Oracle CQL Language Reference for Oracle Stream Explorer This chapter includes the following sections e Processor Data Sources e Assembly and Configuration Files e Queries e COL Aggregations e Configure a Table Source e Configure an Oracle CQL Processor for Parallel Query Execution e Fault Handling This chapter presents an overview of Oracle CQL with examples to help you understand the basic concepts See Cached Event Data for information about performing CQL queries on caches See also Oracle CQL Language Reference for Oracle Stream Explorer for a reference to Oracle CQL functions queries views joins pattern recognition capabilities and statements Oracle JDeveloper provides Oracle CQL Pattern components that provide templates for creating common Oracle CQL queries See Getting Started with Event Processing for Oracle Stream Explorer This chapter describes some of the assembly and configuration file Oracle CQL Processor settings For a complete reference see Schema Reference for Oracle Stream Explorer 6 1 Processor Data Sources Oracle CQL queries can define one or more statements to process incoming event data from one or more input sources and send the outgoing event data to one or more Oracle CQL Processors 6 1 Assembly and Configuration Files output channels Each channel input or
108. MANIFEST ME File r a a a eaa a aeea aka aa Eio e ei iaai 13 7 13 7 3 Include Third Party JAR Files sssssesnssnsseessestessessessestessesensnestensesnnsnententessnsnentennessesses 13 9 13 7 4 Access Third Party JAR Files with Xbootclasspath ccscscsessssesescecesesesestenenene 13 10 13 7 9 Reference Foreign Stages esien epa na aa a a itv E EREE 13 10 13 7 6 Assemble an OSGi Bundle that Activates cccccecscssesssssssesceseescessecsecseecsecsseeseenses 13 11 13 8 Deploy an OSGi Bundles ron nerens see pee Ea ea ree AEE Aabar E EE eA aaO EE Ran ORDEA 13 14 Testing 1 2 3 14 1 Load Generator and the csvgen Adapter sessssssssssertsssierttssssesttsntesstenttesterttesntentesnteentesnness 14 1 14 1 1 Create the Properties File cccccscccscseststeeseseesesesescecesesssesnansneseseeceseseseecesesessscananenees 14 2 14 1 2 Create the Data Feed File ccc ccccscessesscessesscescecsessceccecsseseecsecsaecaeceasceeceasseesesesensensees 14 2 14 1 3 Configure the csvgen Adapter in Your Application ssss sessssessesiersessissesresressesses 14 3 14 2 Event Inspector Service te reene aee aE E Aaa e EE eA A a A A EEs 14 4 TAZI VEVEN My pes e aa e e e ea a a E A a A A e Ena 14 5 14 2 2 HTTP Publish Subscribe Channel and Server ccccccccsessecssessecsecesecesceseeseceseeeeseeeees 14 6 14 2 3 Configure a Local or Remote Serve cccccceescsecsesssesesescscesesesescsesssesesescseseseseseseses 14 6 TA 24 gt Unject Events
109. MapEvent event inserted public void entryUpdated MapEvent event updatedt 8 8 Configure a Third Party Caching System and Cache You can configure your application to use a third party caching system and cache Configure a Third Party Caching System and Cache 1 Create a plug in to define the third party caching system as an Oracle Stream Explorer caching system provider e Implement the com bea wlevs cache spi CachingSysten interface e Create a factory that creates caching systems of this type e Register the factory with an attribute that identifies its provider type 2 Declare the caching system in the EPN assembly file 8 12 Developing Applications for Event Processing with Oracle Stream Explorer Configure a Third Party Caching System and Cache Use the wlevs caching system element to declare a third party implementation use the class or provider attribute to specify additional information For simplicity you can include the third party implementation code inside the Oracle Stream Explorer application bundle itself to avoid having to import or export packages and manage the life cycle of a separate bundle that contains the third party implementation In this case the wlevs caching system element appears in the EPN assembly file as shown in the following example lt wlevs caching system id caching system id class third party implementation class gt The class attribute specifies a Java class that must
110. N SERVERNAME The name of the Oracle Stream Explorer server where the EPN stage runs APPLICATIONNAME the name of the Oracle Stream Explorer application STAGENAME the name of the EPN stage DIRECTION one of either e input Event injection e output Event tracing For example server 1 myapp MyInputAdapter input The Event Inspector service uses an HTTP pub sub server This can be any of e Local You configure the server file with an event inspector element and configure its pubsub server name child element with the name of the local pubsub server that is running on this machine e Remote You configure the server file with an event inspector element and configure its pubsub server url child element with a URL to an HTTP pub sub server that is running on a remote machine e Default if there is only one HTTP pub sub server defined in the server file and you do not specify a local or remote HTTP pub sub server the Event Inspector service uses the local HTTP pub sub server by default The Event Inspector service uses the same HTTP pub sub channel and server for tracing and injecting events 14 2 3 Configure a Local or Remote Server You can configure the Event Inspector service with a local or remote HTTP pub sub server You configure the Event Inspector HTTP pub sub server in a component configuration file When there is only one HTTP pub sub server defined in the server 14 6 Developing Applications for Event Processin
111. OCD gt 11 3 Attribute Descriptions Every AD requires the name id and description parameters The following example is an OCD with two ADs The OCD provides a common definition for the channel component and provides parameterized attributes ADs for the maximum number of threads and the maximum buffer size of the channel When the user runs the application the application displays the description and the other information that you provided and waits for the user to enter the requested information and press the Return key lt OCD name Channel Configuration id com oracle cep channel description The channel definition in the OCEP Application ocep binding jmx EventChannel gt lt AD name Max Threads id maxThreads type Integer required true default 0 min 0 max 100 description Number of threads generating messages ocep binding MaxThreads gt lt AD name Max Size id maxSize type Integer required true default 0 min 0 max 100 description The maximum size of the FIFO buffer for this channel ocep binding MaxSize gt lt OCD gt Note To avoid errors always define Max Threads before Max Size in the metatype file For the 12c release the only supported binding is Java Management Extension JMX This means that the AD attributes must be bound to a corresponding JMX attribute See Targeting 11 4 Targeting You can connect an OCD and an application component with the Designate element
112. ORACLE Oracle Fusion Middleware Developing Applications for Event Processing with Oracle Stream Explorer 12c Release 12 2 1 E56587 01 October 2015 How to design and create Oracle Event Processing scalable applications to process streaming events Oracle Fusion Middleware Developing Applications for Event Processing with Oracle Stream Explorer 12c Release 12 2 1 E56587 01 Copyright 2007 2015 Oracle and or its affiliates All rights reserved Primary Authors Madhubala Ponnekanti Oracle Corporation This software and related documentation are provided under a license agreement containing restrictions on use and disclosure and are protected by intellectual property laws Except as expressly permitted in your license agreement or allowed by law you may not use copy reproduce translate broadcast modify license transmit distribute exhibit perform publish or display any part in any form or by any means Reverse engineering disassembly or decompilation of this software unless required by law for interoperability is prohibited The information contained herein is subject to change without notice and is not warranted to be error free If you find any errors please report them to us in writing If this is software or related documentation that is delivered to the U S Government or anyone licensing it on behalf of the U S Government then the following notice is applicable U S GOVERNMENT END USERS Oracle
113. Source lt wlevs event bean id simpleBean class SimpleBean gt lt wlevs resource property dataSource gt lt wlevs event bean gt Example 2 3 Static Resource Injection Using Static Resource Names Annotations import javax annotation Resource public class SimpleBean implements EventBean Resource name StockDs public void setDataSource DataSource dataSource this dataSource dataSource 2 5 2 2 Dynamic Resource Names A dynamic resource name is one that is specified as part of the dynamic or external configuration of an application Using a dynamic resource name the deployer or administrator can change the resource name without requiring that the application developer modify the application code or the Spring application context To add a dynamic resource name to a component such as an adapter or POJO you must first specify custom configuration for your component that contains the resource name lt simple bean gt lt name gt SimpleBean lt name gt lt trade datasource gt StockDs lt trade datasource gt lt simple bean gt To configure static resource injection using dynamic resource names at design time use the standard javax annotation Resource annotation To override design time configuration at deploy time you use Oracle Stream Explorer assembly file XML import javax annotation Resource public class SimpleBean implements EventBean Resource name trade datasource public void setData
114. Source DataSource dataSource this dataSource dataSource lt wlevs event bean id simpleBean class SimpleBean gt lt wlevs resource property dataSource name trade datasource gt lt wlevs event bean gt 2 8 Developing Applications for Event Processing with Oracle Stream Explorer Resource Access Configuration 2 5 3 Dynamic Resource Injection Dynamic resource injection refers to the injection of resources dynamically while the component is active in response to a dynamic configuration change using Spring container method injection To configure dynamic resource injection at design time use the standard javax annotation Resource annotation as Example 2 4 shows The component calls the get DataSource method at runtime whenever it needs to retrieve a new instance of the resource that the resource name trade datasource refers to Typically the component calls the getDataSource method during the Prepare or Activate methods when dynamic configuration changes are handled For more information see Schema Reference for Oracle Stream Explorer Another strategy is to always call the get DataSource prior to using the data source That is the application code does not store a reference to the data source as a field in the component Example 2 4 Dynamic Resource Injection Annotations import javax annotations Resource public class SimpleBean implements EventBean Resource trade datasource public abstract Data
115. Source getDataSource 2 5 4 Dynamic Resource Lookup Using JNDI Oracle Stream Explorer supports the use of JNDI to look up resources dynamically import javax naming InitialContext public class SimpleBean implements EventBean public abstract void getDataSource throws Exception InitialContext initialContext new InitialContext return initialContext lookup StockDs The JNDI name StockDs must exactly match the name of the data source in the Oracle Stream Explorer server file Note You must disable security when starting the Oracle Stream Explorer server in order to use JNDI Oracle does not recommend the use of JNDI for this reason For more information see Administering Oracle Stream Explorer Application and Resource Configuration 2 9 Resource Access Configuration 2 5 5 Resource Name Resolution Oracle Stream Explorer server resolves resource names by examining the naming scopes that Table 2 1 lists Table 2 1 Resource Name Resolution Naming Contents Resolution Scope Behavior Component The property names of the component s custom Mapping configuration Application The names of the configuration elements in the Matching application configuration files Server The names of the configuration elements in the server Matching configuration file JNDI The names registered in the server s JNDI registry Matching Each naming scope contains a set of unique names The name resolution beha
116. Suspend the Application Oracle Stream Explorer performs the following actions 1 Oracle Stream Explorer calls the SuspendableBean suspend method on all SuspendableBeans 1 6 Developing Applications for Event Processing with Oracle Stream Explorer API Overview 2 Application state is now SUSPENDED Resume the Application Oracle Stream Explorer performs the following actions 1 Oracle Stream Explorer calls the ResumableBean beforeResume method on all ResumableBeans 2 For each bean that implements RunnableBean starts it running ina thread 3 Application state is now RUNNING Uninstall the Application Oracle Stream Explorer performs the following actions 1 Oracle Stream Explorer calls the SuspendableBean suspend method on all SuspendableBeans 2 Oracle Stream Explorer unregisters MBeans 3 calls the DisposableBean dispose method on all DisposableBeans 4 Oracle Stream Explorer uninstalls application bundle from OSGI Updating the application This is equivalent to first uninstalling an application and then installing it again See those user actions in this list Call Methods of Stream and Relation Sources and Sinks You cannot call a method on a stream or relation source or sink from a life cycle callback because components might not be ready to receive events until after these phases of the application life cycle completes For example you cannot call St reamSender method sendInsertEvent fr
117. ack configuration file elements 1 Open the component configuration XML file and add a playback parameters child element to the component you want to configure to playback events For example to configure a channel called event Stream lt channel gt lt name gt event St ream lt name gt lt playback parameters gt lt playback parameters gt lt channel gt 2 Add child elements to playback parameters to specify a data set one or more events to be played back and so on For example lt channel gt lt name gt event Stream lt name gt lt playback parameters gt lt dataset name gt recplay_sample lt dataset name gt lt event type list gt lt event type gt SimpleEvent lt event type gt lt event type list gt lt playback parameters gt lt channel gt Table 15 3 lists the child elements of playback parameters that you can specify Only dataset name is required Table 15 3 Child Elements of playback parameters Child Element Description dataset name event type list Berkeley DB Identifies the recorded data and places it in a directory of this name below the directory specified by the do env path setting in the server config xml file Oracle RDBMS based provider Specifies the database area or schema in which the tables that store the recorded events are created When you configure the Oracle RDBMS based provider you must specify this element When you configure the Oracle RDBMS ba
118. ad makes to write to the store buffer The user thread is the thread that creates or updates a cache entry If all attempts by the user thread to write to the store buffer fail it will invoke the store synchronously batch write attempts The default value is 1 e The time in milliseconds the user thread waits before aborting an attempt to write to the store buffer buffer write timeout The attempt to write to the store buffer fails only when the buffer is full After the time out further attempts can be made to write to the buffer based on the value of buf fer write attempts The default value is 100 lt caching system gt lt name gt caching system id lt name gt lt cache gt lt name gt cache id lt name gt lt max size gt 100000 lt max size gt lt eviction policy gt LRU lt eviction policy lt time to live gt 3600 lt time to live gt lt write behind gt lt buffer size gt 200 lt buffer size gt lt buffer write attempts gt 2 lt buffer write attempts gt lt buffer write timeout gt 200 lt buffer write timeout gt lt write behind gt lt cache gt lt caching system gt The following configuration file settings add a listeners child element to configure the behavior of components that listen to the cache The 1istener element has an asynchronous attribute that you can set to either t rue listeners are invoked asynchronously or false listeners are invoked synchronously The work manager name child e
119. ailability correlating output adapter is wlevs adapter with the provider element set to ha correlating as shown lt wlevs adapter id myCorrelatingAdapter provider ha correlating gt lt wlevs listener gt lt bean class com bea wlevs example cluster ClusterAdapterBean gt lt wlevs listener gt lt wlevs instance property name correlatedSource ref clusterCorrOutstream gt lt wlevs instance property name failOverDelay value 2000 gt lt wlevs adapter gt Table 17 12 describes the additional child elements Table 17 12 Child Elements Child Element Description wlevs listener Specify the regular output adapter downstream from this Oracle Stream Explorer high availability buffering output adapter wlevs instance Specify one or more instance property element name and property value attributes as Table 17 13 describes Table 17 13 lists the instance properties Table 17 13 Instance Properties Name Value correlatedSource Specify the event source to correlate against Events seen from this source are purged from the trimming queue Events still in the queue at failover are replayed failOverDelay Specify the delay timeout in milliseconds that is used to decide how soon after failover correlation should restart Default 0 ms Configuration File The root element for configuring an Oracle Stream Explorer high availability correlating output adapter is ha correlating adapter The name ch
120. also allowed to update it e Use acache in a multiserver domain If you build an Oracle Stream Explorer application that uses a cache and you plan to deploy that application in a multiserver domain then you must use a caching system that supports a distributed cache In this case you must use either Oracle Coherence or a third party caching system that supports a distributed cache For more information see Administering Oracle Stream Explorer Configure an Oracle Coherence Caching System and Cache Configure a Third Party Caching System and Cache 8 2 Configure an Oracle Coherence Caching System and Cache You can configure your application to use the Oracle Coherence caching system and cache Use this caching system if you plan to deploy your application to a multiserver domain When you configure with Oracle Coherence only the first caching system can be configured in a server The Oracle Stream Explorer server ignores other caching systems that you have configured Cached Event Data 8 3 Configure an Oracle Coherence Caching System and Cache Note Before you can legally use Oracle Stream Explorer with Oracle Coherence you must obtain a valid Coherence license such as a license for Coherence Enterprise Edition Coherence Grid Edition or Oracle WebLogic Application Grid For more information on Oracle Coherence see http docs oracle com middleware 1213 coherence index html The following assembly and con
121. alue of the HelloWorldAdapter Java class An adapter is created from the Hel loWorldAdapter Java class The OBR adapter configuration includes a message element with the specified message text The He loWorldAdapter class prints the message during application execution In this example the HelloWorldAdapter class is the event source The OBR adapter declaration comes after the channel and Oracle CQL processor configurations lt wlevs adapter id OBRAdapter provider obr gt followed by the decisionFunction and dictionaryURL properties The dictionaryURL property is the path to the OBR dictionary file that contains the rules and decisionFunction property is the OBR function you want to use The handlerl1 property is a handle for other components to access this information Adapters 4 17 Oracle Business Rules Adapter Note The OBR adapter does not handle automatic Fact retraction If the upstream processor outputs a stream retract the Fact in the rule file when appropriate or when the last rule is triggered according to rule priority At the bottom is the Hel loWorldBeand configuration The HelloWorldBean isa Java class that instantiates the Hel loworldEvent and HelloWorldAdapter classes lt wlevs event type repository gt lt wlevs event type type name HelloWorldEvent gt lt wlevs class gt com bea wlevs event example helloworld HelloWorldEvent lt wlevs class gt lt wlevs event type gt lt wle
122. am Explorer application EPN assembly file to add an Oracle Stream Explorer high availability input adapter as shown Adda wlevs adapter element with provider set to ha inbound after the regular input adapter JMSInboundAdapter Adda wlevs listener element to the regular input adapter JMS InboundAdapter that references the ha inbound adapter by its id Add a wlevs source element to the channel channe11 that references the ha inbound adapter by its id lt wlevs event type repository gt lt wlevs event type type name StockTick gt lt wlevs properties gt lt wlevs property name lastPrice type double gt lt wlevs property name symbol type char gt lt wlevs properties gt lt wlevs event type gt lt wlevs event type repository gt lt wlevs adapter id JMSInboundAdapter provider jms inbound gt lt wlevs listener ref myHaInputAdapter gt lt wlevs adapter gt High Availability Applications 17 29 Configure High Availability Quality of Service lt wlevs adapter id myHaInputAdapter provider ha inbound gt lt wlevs adapter gt lt wlevs channel id channell event type StockTick gt lt wlevs listener ref processorl gt lt wlevs source ref myHaInputAdapter gt lt wlevs channel gt 5 Configure your Oracle Stream Explorer application EPN assembly file to add an Oracle Stream Explorer high availability correlating output adapter as shown e Addawlevs adapter element with provide
123. ame of this class is used as the context path when initializing the JAXBContext represented by the mapper bean The configuration must specify either an event TypeName or a contextPath to be used in constructing the context path for the JAXBContext represented by the mapper The packages must exist on the classpath of the application and contain either schema generated classes JAXB annotated classes or classes referenced by Moxy external metadata The classes will be used as the Java object graph for marshalling and unmarshalling operations See Schema Reference for Oracle Stream Explorer for information about the JAXBContext newInstance method A colon separated list of Java package names The specified context path to initialize the JAXBContext represented by the mapper bean The configuration must specify either an eventTypeName ora contextPath to be used in constructing the context path for the JAXBContext represented by the mapper The packages must exist on the classpath of the application and contain either schema generated classes JAXB annotated classes or classes referenced by Moxy external metadata The classes will be used as the Java object graph for marshalling and unmarshalling operations Boolean value that defaults to false When true you must provide the schema Schema validation occurs during marshalling and unmarshalling The file name of the XML schema file used for validation Package the schema file
124. an assembly file entry shows the event bean id associated class and that the event bean listens for events from the upstream BeanOutputChannel component 7 2 Developing Applications for Event Processing with Oracle Stream Explorer Event Sink Interfaces lt wlevs event bean id eventBean class tradereport TradeEvent gt lt wlevs listener ref BeanOutputChannel gt lt wlevs event bean gt Configuration File The following event bean configuration file entry shows an event bean configured with the record parameters child element lt event bean gt lt name gt eventBean lt name gt lt record parameters gt lt dataset name gt t radereport_sample lt dataset name gt lt event type list gt lt event type gt TradeEvent lt event type gt lt event type list gt lt batch size gt 1l lt batch size gt lt batch time out gt 10 lt batch time out gt lt record parameters gt lt event bean gt 7 1 4 Create a Spring Bean You can configure a Java class as a Spring bean to include the class in an event processing network This is a good option if you have an existing Spring bean that you want to incorporate into the EPN or if you want to incorporate Spring features into your Java code In a Spring bean you plan to add to an EPN you can implement the various life cycle interfaces These include InitializingBean DisposableBean and the active interfaces such as RunnableBean The Spring bean event source can also use
125. an event based on the event type name The event is created only when it is available in the Event Type repository MapEventObject createMapEvent EventChannel channel Map lt String Object gt event Create a map event for a metadata based channel void sendInsert String channelName Object event Send an insert event to the channel void sendUpdate String channelName Object event Send an update event to the channel void sendDelete String channelName Object event Send a delete event to the channel void sendHeartbeat Long timestamp String channelName Senda heartbeat to the channel 14 4 3 Example The following example shows a basic JUnit test case Get the OSGI service ServiceReference ref ctx getServiceReference EpnCommand class getName commandSession EpnCommand ctx getService ref Begin a session 14 16 Developing Applications for Event Processing with Oracle Stream Explorer EPN Command Interface commandSession begin Create an Oracle CQL processor Processor pl commandSession createProcessor p1 Create two stream channels from the MyEvent Java class EventChannel chl commandSession createChannel false cl MyEvent class EventChannel ch2 commandSession createChannel false c2 MyEvent class Create a listener to retrieve events that equal event el The MyEventListener class implements the StreamSink or Relat
126. and Deploy 13 11 Assemble an OSGi Bundle with bundle sh Argument Description service INTERFACE fragmenthost HOST stagedir PATH targetdir PATH import PACKAGE REGEX imods REGEX MODS import PACKAGE export PACKAGE REGEX emods REGEX MODS dimport PACKAGE explode verbose An optional argument that specifies a space delimited list of one or more Java interfaces that are used as the object class of each factory object service registration If no interface names are specified or the number of interfaces specified does not match the number of factory classes then each factory object will be registered under the factory class name An optional argument indicating that the resultant bundle is a fragment bundle and specifies the symbolic name of the host bundle This argument is incompatible with the factory argument An optional argument that specifies where to write temporary files when creating the target JAR file Default bundler tmp An optional argument that specifies the location of the generated bundle JAR file Default current working directory A space delimited list of one or more packages or regular expressions that select the packages to exclude from the manifest Import Package attribute By default all dependent packages will be imported except java The import modifiers are applied to the packages matching regular expression Add
127. ane riesene Aae aoao eaea a Ea Raa ERE Ea EERE R AE REEE ERASOA 7 3 Event Sink Intertaces inomin ene e ee e nt e ares lacs Coe ai ae e aa te an ease ea nEn a Saa 7 3 7 2 1 Implement StreamSink neesto eais ipare nisen etere eeri e e aia asai einean a eieae 7 4 7 2 2 Implement RelatonSiikK sertie ais ipare inisee eera e e aiaiai einean a eieae t 7 5 Event SOurce Interlaces s miere ke ce Lae stale cache Hath ene esha hee aah eea eed asda adh coe ot eed 7 6 7 3 1 Implement StreamSender cceccccsesccscsesessesetesescecesesescenenssesesesnenssescecesesesssnanenensseseseneneseees 7 7 7 3 2 Implement RelationSender ccccccccsesessesesesescecesesescenenesesesesenssescecesesesssnananeneseseeseneneeees 7 7 Cached Event Data 8 1 8 2 8 3 8 4 8 5 8 6 8 7 8 8 Caching Defined reris Wks shoe aren hate op Teast ca Hee ts shea deh ee ed ea aea oa aSa s 8 1 8 1 1 Supported Caching Implementations ccccccceccssseststeeseseeseseseeeeeesesssesnasneseseeneneneeees 8 2 8 1 2 USE Cases tonne mee ete tuts i a shes epee a ha Aa ete et ainia aiaa 8 2 Configure an Oracle Coherence Caching System and Cache cccsesceescsseseseseeneesesesnenenens 8 3 8 21 Assembly Filen s sees saecacoss roen sabe Geta to coh shade andes a ed etaith a eacdereeas beh OE 8 4 8 2 2 Configuration Flessen Lo bess th ansat E dosent oth oh a Seka 8 5 8 2 3 Cache Loader Beant i i se si ccevcitie ce nn seie Sateen aetna det eal ieee 8 7 Configure a Local Cac
128. annel to reference the ha buf fering adapter by its id Add a wlevs listener element to the ha buf fering adapter that references the Hel 1oWorldBean class levs event type repository gt lt wlevs event type type name HelloWorldEvent gt lt wlevs class gt com bea wlevs event example helloworld HelloWorldEvent lt wlevs class gt lt wlevs event type gt lt wlevs event type repository gt lt w lt w evs adapter id helloworldAdapter class com bea wlevs adapter example helloworld HelloWorldAdapter gt evs instance property name message value HelloWorld the current time is gt lt wlevs adapter gt lt w evs channel id helloworldInputChannel event type HelloWorldEvent gt lt wlevs listener ref helloworldProcessor gt lt wlevs channel gt lt w lt w lt evs processor id helloworldProcessor gt evs channel id helloworldOutputChannel event type HelloWorldEvent advertise true gt lt wlevs listener ref myHaSlidingWindowAdapter gt lt wlevs source ref helloworldProcessor gt wlevs channel gt lt wlevs adapter id myHaSlidingWindowAdapter provider ha buffering gt lt lt wlevs listener gt lt bean class com bea wlevs example helloworld HelloWorldBean gt lt wlevs listener gt wlevs adapter gt 5 Optionally configure the channel downstream from the input adapter helloworldInputChannel to configure an application time stamp based
129. apacity with Partitioning Queries In general you will probably see improved performance for queries by making more threads available and setting the ordering constraint attribute so that they re able to execute in parallel when possible As with most performance tuning techniques a little trial and error with these settings should yield a combination that gets better results However in some cases where your queries use partitioning and you ve set the ordering constraint attribute to PARTITION_ORDERED you might not see the amount of scaling you d expect For example consider a case in which running with four threads doesn t improve performance very much over running with two threads In such a case you can try using the partition order capacity value to get the most out of COL engine characteristics at work with queries that include partitions The partition order capacity value specifies the maximum amount of parallelism that will be permitted within a given processor instance when processing a PARTITION_ORDERED query When available threads are handling events belonging to different partitions the value sets a maximum number of threads that will be allowed to simultaneously run in the query As with other aspects of performance tuning getting the most out of partition order capacity may take a bit of experimentation When tuning with partition order capacity a good starting point is to set it equal to the maximu
130. approach for applications that need to be highly available The application time is associated with an event before the event is sent downstream so it is consistent across active primary and secondary servers System time can cause application instances to generate different results because the time value associated with an event can be different on each server due to system clocks not being synchronized You can use system time for applications when Oracle CQL queries do not use time based windows Applications that use only event based 17 18 Developing Applications for Event Processing with Oracle Stream Explorer Configure High Availability Quality of Service windows depend only on the arrival order of events rather than the arrival time so you can use system time in this case If you must use system time with Oracle CQL queries that do use time based windows then you must use a Oracle Stream Explorer high availability input adapter that intercepts incoming events and assigns a consistent time that spans primary and secondary servers 17 9 Configure High Availability Quality of Service You configure Oracle Stream Explorer high availability quality of service in the assembly and component configuration files After you make Oracle Stream Explorer high availability configuration changes you must redeploy your Oracle Stream Explorer application This section includes the following procedures e Configure a Simple Failover e Configu
131. arguments must be in body lt messagebody gt lt messagedetail gt File 0 does not exist The server will restore the file contents from 1 resulting in the use of default values for all future requests lt messagedetail gt lt cause gt The file was deleted lt cause gt lt action gt If this error repeats then investigate unauthorized access to the file system lt action gt An example of a method attribute is as follows method logNoFile String name String path The message example expects two arguments 0 and 1 e Both are used in the lt messagebody gt e Both are used in the lt messagedetail gt e Neither is used in lt cause gt or lt action gt Internationalization 12 3 Message Catalogs 12 1 4 Formats The catalog format for top level and locale specific catalog files differs Top level catalogs define the textual messages for the base locale Locale specific catalogs only provide translations of text defined in the top level version Also log message catalogs are defined differently from simple text catalogs Log Message Catalog This example shows the MyUt ilLog xml message catalog that has one log message to show how to use the messagebody messagedetail cause and action elements lt xml version 1 0 gt lt DOCTYPE message_catalog PUBLIC weblogic message catalog dtd http www bea com servers wls90 dtd msgcat dtd gt lt message_catalog 110n_package programs utils i18n_packag
132. arshall and unmarshall event data between XML and Java objects The JAXB interface supports the JAXB 2 2 specification and EclipseLink Moxy provider extensions You can configure the mapping operations in the following ways e Map from an XML schema to Java objects to output a set of annotated Java classes e Map from one set of Java objects to another set of Java Objects or to XML using JAXB annotations e Map from an existing XML schema to an existing predefined Java object representation This approach uses the EclipseLink Moxy extensions and requires an external met adata file that contains the mapping details The met adata file is referenced by the application configuration 4 4 1 EclipseLink Moxy 4 4 2 APIs EclipseLink Moxy provides extensions that enable you to map between an existing XML schema and a predefined set of Java classes without modifying the XML schema or the Java classes without providing annotations You provide the mapping information in an external metadata file using a XPath syntax The flexible EclipseLink Moxy extensions enable you to perform complex operations For example you can map a subset of complex XML data to a much simpler event representation You can also flatten a deeply nested XML document into a flat Java bean event format for processing by Oracle CQL You specify EclipseLink Moxy external met adata in XML Access the schema at http www eclipse org eclipselink xsds eclipselink_oxm_2_2 xsd
133. artbeat Logon TestRequest ResendRequest Reject SequenceReset Logout 4 13 2 Configure QuickFix Adapters Oracle JDeveloper does not currently provide a component for the QuickFix adapter However you can create a QuickFix adapter by adding entries to the assembly and configuration files for your Oracle Stream Explorer application Assembly File lt wlevs adapter id QuickFIXInbound provider quickfix inbound gt Configuration File The configuration requires at least one default session element and can have zero or more session elements The session element represents a group of configuration settings that is used for a particular QuickFix Session If there are more than one sessions required then common configurations are grouped into the default session element All of the session tags by default inherit all of the elements declared in the default session tag The BeginString value in the config name element indicates the FIX message version used BeginString data is not validated by the QuickFIX engine According to the documentation at http quickfixj org quickfixj usermanual 1 5 3 usage configuration html the required and supported identifier fields are BeginString SenderCompID and TargetCompID Other fields such as SenderSubID SenderLocationID Target SubID and Target LocationID are not mandatory and are not supported in release 12 1 3 lt quickfix adapter gt lt name gt quickfixAdpater lt name gt lt
134. articular command type help lt command gt For example to see help about the begin command type the following g help begin begin Begins new session for invoking EPN commands scope epn parameters CommandSession 14 10 Developing Applications for Event Processing with Oracle Stream Explorer EPN Shell Note Some of the Apache Felix Gogo commands have a CommandSession argument which is an internal shell argument that does not execute with the Apache Felix Gogo commands When you do a help listing for some of the EPN shell commands the CommandSession parameter is listed by the help but does not work 14 3 1 Oracle CQL Queries By default an EPN session has an implicit Oracle CQL processor that is connected to an event sink that prints all outputs to the shell console To test Oracle CQL queries create an input channel define the queries and send events as follows g begin g channel MyChannel msg String MyChannel g query select from MyChannel q0 g send MyChannel msg Hi 11 14 26 618 gt insert event msg Hi q end Use the begin command to start an EPN session and the end command to end an EPN session Ending a session destroys all EPN components that were created during that session A session is not multithread aware The channel command creates MyChannel with an event type that has the msg property of type String You can also specify a Java class name for the event type The query
135. as exceptions to the handler There you can handle or rethrow the exception e Allow query processing to continue as your code either handles the exception or rethrows it to the stage that is next upstream e Save event data from being lost while handling a fault For example if you have configured a connection to a data source you could save event data there e Log fault and event information when faults occur e Use multiple fault handlers where needed in an EPN so that exceptions thrown upstream are handled when they reach other Oracle CQL processors and channels Consider associating a fault handler with a stage that does not have its own mechanism for responding to faults including Oracle CQL processors and multithreaded channels Other stages such as custom adapters that have their own exception handling model do not benefit from a fault handler Queries can continue as your fault handling code evaluates the fault to determine what action should be taken including rethrowing the fault to a stage that is upstream from the Oracle CQL processor Oracle CQL Processors 6 15 Fault Handling For example the upstream stage of the Oracle CQL processor could be the JMS subscriber adapter which can roll back the JMS transaction if the session is transacted to allow the event to be redelivered It can also commit the transaction if the event has been redelivered already and found that the problem is not solvable Note that when
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137. ass public int getOrderID return orderID public setOrderID int orderID this orderID orderID public int getAccountID return accountID public setOrderID int accountID this accountID accountID public int hashCode int hash 1 ash hash 31 orderID hashCode ash hash 31 accountID null 0 accountID hashCode return hash public boolean equals Object obj if obj this return true if obj null return false if obj instanceof MyCompoundKeyClass return false MyCompoundKeyClass k MyCompoundKeyClass obj return k accountID accountID amp amp k orderID orderID 7 Configure the channel downstream from the high availability input adapter helloworldInputChannel to configure an application time stamp based on the high availability input adapter timeProperty setting as the following example shows The wlevs expression should be set to the timeProperty value lt wlevs adapter id myHaInputAdapter provider ha inbound gt lt wlevs instance property name keyProperties value id gt 17 26 Developing Applications for Event Processing with Oracle Stream Explorer Configure High Availability Quality of Service lt wlevs instance property name eventType value HelloWorldEvent gt lt wlevs instance property name timeProperty value arrivalTime gt lt wlevs adapter gt lt wlevs channel id helloworldInputChannel ev
138. ast output adapter uses to identify event instances If you specify more than one event property you must specify a keyClass Default all event properties keyClass Specify the fully qualified class name of a Java class used as a compound key By default all JavaBean properties in the keyClass are assumed to be keyProperties unless the keyProperties setting is used A compound key may be monotonic and may be totalOrder monotonic Specify whether the key value is constantly increasing like a time value Valid values are e true the key is constantly increasing e false the key is not constantly increasing Default false 17 38 Developing Applications for Event Processing with Oracle Stream Explorer Configure High Availability Adapters Name Value totalOrder Specify whether event keys are unique Applicable only when instance property monotonic is set to t rue Valid values are e true event keys are unique e false event keys are not unique Default t rue Configuration File The root element for configuring an Oracle Stream Explorer high availability broadcast output adapter is ha broadcast adapter The name child element for a particular adapter must match the id attribute of the corresponding wlevs adapter element in the EPN assembly file that declares this adapter as shown lt ha ha broadcast adapter gt lt name gt myBroadcastAdapter lt name gt lt trimming interval units events gt
139. ation When the inbound JMS adapter is multi threaded event order is not guaranteed To use multiple threads configure the adapter with a work manager with the work manager child element You can specify a dedicated work manager to be used only by the adapter or you can share a work manager among several components such as other adapters and Jetty 4 10 2 2 Configure a JMS Adapter for Durable Subscriptions You can configure an inbound JMS adapter to be a client in a durable subscription to a JMS topic A durable subscription ensures that the adapter receives published messages even when the adapter becomes inactive When the inbound adapter connects to the JMS server it registers the durable subscription and subsequent messages sent to the topic are retained during periods when the subscriber is disconnected unless they expire and delivered when the subscriber reconnects Adapters 4 13 JMS Custom Message Converter Bean A durable subscription assumes that the publisher that is publishing JMS messages to the topic is using the persistent delivery mode Note that publisher might be the Oracle Stream Explorer outbound JMS adapter in other words its delivery mode value must be persistent the default value Create a Durable Subscription in the Adapter 1 Ensure that the JMS message publisher is delivering messages in persistent mode 2 Specify a client ID for the connection factory On Oracle WebLogic Server the client ID can be s
140. ation to remove the previous average and then sends an insert event to the relation to add the new average into the relation The following example uses the ISTREAM operator to update the output stream when a new average is calculated ISTREAM SELECT AVG price FROM StockTradeIStreamChannel RANGE 1 MINUTE The following configuration file entry shows the ISTREAM operator lt processor gt lt rules gt lt query id rule2 lt CDATA ISTREAM SELECT AVG price FROM StockTradeIStreamChannel RANGE 1 MIN gt lt query gt lt rules gt lt processor gt DSTREAM Operator Use the DSTREAM operator to find out when a situation is no longer useful such as when a stock has been delisted from the exchange The following example uses the DSTREAM operator to update the output stream with the old average after the new average is calculated in the relation DSTREAM SELECT AVG price FROM StockTradeIStreamChannel RANGE 1 MINUTE The following configuration file entry shows the DSTREAM operator lt processor gt lt rules gt lt query id rule2 lt CDATA DSTREAM SELECT AVG price FROM StockTradeIStreamChannel RANGE 1 MIN gt lt query gt lt rules gt lt processor gt RSTREAM Operator The RSTREAM operator inserts all events into the output stream regardless of whether events were deleted or updated Use this operator when you need to take downstream action on every output The following examples us
141. ava util HashSet import java util Map import java util Set import com bea wlevs example provider event ProviderData import com tangosol net cache CacheLoader public class LocalLoader implements CacheLoader public static int loadCount 0 public static Set keys new HashSet public LocalLoader public Object load Object key loadCount keys add key return new ProviderData String key public Map loadAll Collection keys Map result new HashMap Cached Event Data 8 15 Exchange Data Between a Cache and Another Data Source for Object key keys result put key load key return result 8 9 2 Exchange Data with a Read Write Data Source Using a cache store you can have a cache in your EPN exchange data with a read write data source A cache store is a Java class that exchanges cache objects with a cache You create a cache store by writing a Java class that implements the appropriate interfaces to enable it to communicate with the data source Then you add the cache store to the EPN by using the wlevs cache store child element of the wlevs cache element to specify the bean that communicates with the data source If the backing store is read only use a cache loader instead see Load Cache Data from a Read Only Data Source When creating a cache store you implement interfaces as follows e To exchange cache data with an Oracle Coherence cache create a class that implements th
142. ave one or more assembly files and one or more configuration files You decide how many configuration files to use and what to name them when you build the EPN Your project must have one configuration file named prcessor xml to contain the Oracle CQL processor configuration settings When you create components such as adapters the processor xml file displays as the default configuration file in the new component wizard If you take the default the component configuration information is stored in the default procesor xml To put all of your adapter configurations in one file named adapter xml change processor xml to adapters xml in the wizard In the component configuration wizard if you specify a new file name such as adapters xm1 but use only default settings Oracle JDeveloper does not generate the new file because there are no configuration settings to store in it You can either create the component again with a custom setting or use the File menu to create a new empty configuration file See Getting Started with Event Processing for Oracle Stream Explorer The assembly and configuration files are stored in the following locations within your project Application and Resource Configuration 2 1 Assembly File Structure e Assembly files lt Project Name gt META INF spring xml y g e Configuration files lt Project Name gt META INF wlevs xml You can modify the configuration by editing the application assembly fi
143. bes the attributes in this file lt endpoints gt lt endpoint gt lt name gt EchoService lt name gt lt implementation class gt com bea wlevs test echo impl EchoServiceImpl lt implementation class gt lt url pattern gt echo lt url pattern gt lt wsdl location gt META INF wsdl echo wsdl lt wsdl location gt lt service name gt http wsdl oracle com examples cep echo EchoService lt service name gt lt port name gt http wsdl oracle com examples cep echo EchoServicePort lt port name gt lt endpoint gt lt endpoints gt Table 10 1 bea jaxws xml File Attributes Attribute Description name The name of the web service implementation The class that implements the service class url pattern The url pattern to access the web service wsdl location Relative path to the wsdl in the bundle service name QName of the service port name QName of the port 4 Reference the bea jaxws xml file in the MANIFEST MF file with the BEA JAXWS Descriptor header BEA JAXWS Descriptor META INF bea jaxws xml 5 Add the Import Package header and packages to the MANIFEST MF file to import the following packages to the application Import Package com ctc wstx stax com bea core ws glassfish jaxws com sun xml bind v2 com sun xml messaging saaj soap com sun xml ws javax jws javax xml bind javax xml bind annotation javax xml namespace Web Services 10 3 Expose an Application as
144. bleBean interface The infrastructure uses a work manager associated with the application for spawning the thread You can associate a work manager to an application by naming the work manager with the same name as the application If you do not explicitly specify a work manager for your application then Oracle Stream Explorer creates a work manager with default values for the minimum MIN and maximum MAX number of threads If you need finer control over the threading a custom event bean can implement the interface com bea wlevs ede spi WorkManagerAware In this case the event bean is injected with the work manager of the application during initialization The work manager can be used to explicitly manage the threading for the event bean instance 7 1 2 Receive Heartbeat Events Implement the com bea wlevs ede api HeartbeatAware interface if you want your event bean to receive heartbeat events A heartbeat event is an event of type heartbeat that you can use to model the advance of time This interface has the onHeartbeat long timestamp callback method to implement 7 1 3 Create an Event Bean An event bean is an EPN component that applies logic to events as they pass through The event bean logic is defined by its JavaBean event type This chapter describes some of the assembly and configuration file event bean settings For a complete reference see Schema Reference for Oracle Stream Explorer Assembly File The following event be
145. bout the high availability adapter 17 2 Developing Applications for Event Processing with Oracle Stream Explorer Life Cycle and Failover Figure 17 2 Oracle Stream Explorer High Availability Life Cycle State Diagram Start Server With Deployed Application Secondary _ _ _ __ Deploy Application Current Primary Fails AA Becoming_Primary Configureable Readiness Threshold Met d Primai 7 Host Fails and Rejoins Domain Unregister Application RuntimeMBean y and Uninstall Completed You cannot specify the initial primary server Initially the first server in the multiserver domain to start up becomes the primary so by starting servers in a particular order you can influence primary selection There is no way to force a particular running server to become the primary If a primary fails and comes back up then it does not automatically become the primary again unless the current primary fails and causes a failover 17 3 1 Secondary Failure In general when a secondary server fails there is no effect on Oracle Stream Explorer application operation as Figure 17 3 shows Regardless of the quality of service you choose there are no missed or duplicate events Figure 17 3 Secondary Failure Input Streams Multi Server Domain Deployment Group and Notification Group Server 1 Server 2 Server 3 Queue Queue Output Streams Primary Secondary
146. bute 11 5 Example metatype File The following code shows the entire metatype file lt MetaData xmlns http www osgi org xmlns metatype v1 1 0 xmlns xsi http www w3 org 2001 XMLSchema instance xsi schemaLocation http www osgi org xmlns metatype vl 1 0 http www osgi org xmlns metatype v1 1 0 metatype xsd gt lt OCD name HelloWorld Sample id com oracle cep sample helloworld description The helloworld OEP application is a sample application for Oracle Event Processing gt lt OCD gt lt OCD name HelloWorld Channel id com oracle cep sample helloworld channel gt lt AD name Max Threads id EventChannel MaxThreads type Integer required true default 0 min 0 max 100 description Number of threads generating helloworld messages gt lt AD name Max Size id maxSize type Integer required true default 0 min 0 max 100 description The maximum size of the FIFO buffer for this channel ocep binding MaxSize gt lt OCD gt lt OCD name HelloWorld Message Filtering id com oracle cep sample helloworld filter gt lt AD name Filter id CQLProcessor parameters type String description Message filter gt lt OCD gt lt Designate pid helloworld gt lt Object ocdref com oracle cep sample helloworld gt lt Designate gt lt Designate pid helloworldInputChannel gt lt Object ocdref com oracle cep sample helloworld channel gt lt Designate gt l
147. ce by using partitioning and batching and includes information specific to high availability performance tuning This chapter includes the following sections e Channel and JMS Performance Tuning e High Availability Performance Tuning 16 1 Channel and JMS Performance Tuning You can tune application performance of by configuring an event partitioner channel batching events and partitioning an incoming Java Message Service JMS stream Event partitioner channel You can improve scalability by configuring an event partitioner channel When you configure a channel to use an event partitioner each time an incoming event arrives the channel selects a listener and dispatches the event to that listener instead of broadcasting each event to every listener for partitioning events on a channel across its output event sinks For more information see Customizing Oracle Stream Explorer Batching channel By default a channel processes events as they arrive Alternatively you can configure a channel to batch events that have the same time stamp and were output from the same query by setting the wlevs channel attribute bat ching to true See Batch Processing Channels for an example Scalability with ActiveActiveGroupBean Use com oracle cep cluster hagroups ActiveActiveGroupBean to partition an incoming JMS stream in Oracle Event Processing applications with the notification groups that the Act iveAct iveGroupBean creates For more information s
148. ce injection using e Static Resource Names e Dynamic Resource Names 2 5 2 1 Static Resource Names When you configure static resource injection using static resource names the resource name you use in the Resource annotation or Oracle Stream Explorer assembly XML file must exactly match the name of the resource as you defined it The resource name is static in the sense that you cannot change it without recompiling To configure static resource injection using static resource names at design time you use the standard javax annotation Resource annotation as shown in the example below To override design time configuration at deploy time you use Oracle Stream Explorer assembly file XML In the following examples the resource name St ockDs exactly matches the name of the data source in the Oracle Stream Explorer server file lt wlevs event bean id simpleBean class SimpleBean gt lt wlevs resource property dataSource name StockDs gt lt wlevs event bean gt If the name of the EventBean set method matches the name of the resource then the Resource annotation name attribute is not needed Similarly in this case the wlevs resource element name attribute is not needed Application and Resource Configuration 2 7 Resource Access Configuration import javax annotation Resource public class SimpleBean implements EventBean Resource public void setStockDs DataSource dataSource this dataSource data
149. ched Your implementation of the RelationSource setEvent Sender method receives a sender instance that you can cast to one of the types described in Table 7 3 Use the sender instance to send events to the downstream stage Keep in mind the following constraints for handling the sender instance your class receives e For sendDeleteEvent you must send an instance of the same event type as that configured for the channel Event Beans 7 7 Event Source Interfaces For sendInsertEvent a unique constraint violation exception is raised and the input event discarded if an event with the same primary key is already in the relation For sendUpdateEvent an invalid update tuple exception will be raised and the input event will be discarded if an event with the given primary key is not in the relation In the following example a simple Relat ionSource implementation receives a StreamSender then casts the sender to a RelationSender to send events as a relation This class creates anew TradeEvent instance from the event type configured in the repository but the sendEvent s method could as easily have received an instance as a parameter from another part of the code package com oracle cep example tradereport import com bea import com bea import com bea import com bea import com bea import com bea levs ede api EventType levs ede api EventTypeRepository levs ede api RelationSender levs ede api Relatio
150. cheme gt lt replicated scheme gt lt class scheme gt lt scheme name gt my local scheme lt scheme name gt lt class name gt com tangosol net cache LocalCache lt class name gt lt eviction policy gt LRU lt eviction policy gt lt high units gt 100 lt high units gt lt low units gt 50 lt low units gt lt class scheme gt lt local scheme gt lt scheme name gt test loader scheme lt scheme name gt lt eviction policy gt LRU lt eviction policy gt lt high units gt 100 lt high units gt lt low units gt 50 lt low units gt lt A cachestore scheme element that gets a loader starts here gt lt cachestore scheme gt lt class scheme gt lt class factory name gt com bea wlevs cache coherence configuration SpringFactory lt class factory name gt lt method name gt get Loader lt method name gt lt init params gt lt init param gt lt param type gt java lang String lt param type gt lt param value gt myCoherenceCache lt param value gt lt init param gt lt init param gt lt param type gt java lang String lt param type gt lt param value gt cachel lt param value gt lt init param gt lt init params gt lt class scheme gt lt cachestore scheme gt lt The cachestore scheme element ends here gt lt local scheme gt lt local scheme gt lt scheme name gt test store scheme lt scheme name gt lt eviction policy gt LRU lt eviction policy gt lt high units gt 100 lt high unit
151. cle Stream Explorer EventPartitioner Channels channel exceptions thrown to the channel are received by the handler which contains code to either handle the fault or throw it again If your fault handling code throws the exception again the exception is logged but events related to the exception are lost If you want to keep track of events involved in these exceptions you must persist them with your code such as by writing the event data to a data source connected to your EPN Note To handle an exception thrown by a multithreaded channel the fault handler must be registered in a component that is upstream from the channel such as a processor If you do not register the fault handler with an upstream component the exception is passed upstream but the fault handler is not invoked For information on writing fault handlers see Fault Handling 5 6 EventPartitioner Channels By default a channel broadcasts each event to every listener When you configure a channel to use an EventPartitioner each time an incoming event arrives the channel selects a listener and dispatches the event to that listener instead of broadcasting each event to every listener You can use an EventPartitioner ona channel to improve scalability For more information see Customizing Oracle Stream Explorer 5 7 Distributed Flows The static relationship of an EPN can be represented as an acyclic directed graph that is any pair N C where N is
152. cle Stream Explorer server configuration file on each Oracle Stream Explorer server to add the appropriate Act iveAct iveGroupBean notification group to the groups child element of the cluster element 18 4 Developing Applications for Event Processing with Oracle Stream Explorer Partition an Incoming JMS Event Stream The Oracle Stream Explorer server configuration file is located in Oracle Middleware my_oep user_projects domains lt domain_name gt lt server_name gt config Table 18 2 shows cluster elements for Oracle Stream Explorer servers ocep server 1 ocep server 2 ocep server 3 and ocep server 4 The deployment group is MyDeploymentGroup and the notification groups are defined using default Act iveAct iveGroupBean notification group naming Optionally you can specify your own group naming convention as Notification Group Naming Conventions describes Table 18 1 Server Configuration File Groups Element Configuration Partition cluster Element ocep lt cluster gt server 1 lt server name gt ocep server 1 lt server name gt lt enabled gt coherence lt enabled gt lt groups gt MyDeploymentGroup ActiveActiveGroupBean_group1 lt groups gt lt cluster gt ocep lt cluster gt server 2 lt server name gt ocep server 2 lt server name gt lt enabled gt coherence lt enabled gt lt groups gt MyDeploymentGroup ActiveActiveGroupBean_group2 lt groups gt lt cluster gt ocep lt cluste
153. clients to trace events flowing out of any stage of your EPN To trace events you can either use the Oracle Stream Explorer Visualizer to configure tracing or you can edit a component configuration file in your application to specify trace settings that are in place when the application is deployed or redeployed 14 8 Developing Applications for Event Processing with Oracle Stream Explorer Event Inspector Service Configure event tracing in Oracle Stream Explorer Visualizer with settings that can be discarded when the application is redeployed See Using Visualizer for Oracle Stream Explorer For event tracing configuration settings that are in place when the application is deployed or redeployed configure tracing by editing component configuration settings for the stage from which you want to trace For example the component configuration excerpt shown in the example illustrates how you might configure a processor for event tracing The trace parameters element s active child element specifies that tracing is on while the channel name element specifies the HTTP pub sub channel to which traced elements should be sent lt processor gt lt name gt FindCrossRates lt name gt lt trace parameters gt lt active gt true lt active gt lt channel name gt NonClusteredServer fx FindCrossRates output lt channel name gt lt trace parameters gt lt rules gt lt Query rules omitted gt lt rules gt lt processor gt For r
154. condaries use to trim their output queues If JMS is configured for reliable delivery we can be sure that the stream of events seen by the secondary is precisely the stream of events output by the primary and so failover allows the new primary server to output precisely those events not delivered by the old primary server High Availability Applications 17 11 Design Applications for High Availability Figure 17 7 Precise Recovery with JMS Input Streams Server 1 Server 2 Server 3 Secondary Primary Secondary Queue Queue Output Streams Trim Event Trim Event JMS Provider During failover the new primary server enters the BECOMING_PRIMARY state and does not transition into the PRIMARY state in its event queue that was accumulating as a secondary has been flushed During this transition new input events are buffered and no duplicate events are output When an Oracle Stream Explorer server rejoins the multiserver domain if your application is an Oracle Stream Explorer high availability Type 1 application the application must generate exactly the same sequence of output events as existing secondaries it must wait the warm up window length time you configure for the Oracle Stream Explorer high availability output adapter before it is available as a secondary server To implement the precise recovery with JMS high availability quality of service you configure your EPN with a high availability input adapter after each input adapt
155. configuration metadata annotations such as Prepare Rollback and Activate A Spring bean is a Java class managed by the Spring framework You add a class as a Spring bean by configuring it in the EPN assembly file using the standard bean element A Spring bean is not an Oracle Stream Explorer stage You cannot monitor a Spring bean with the Oracle Stream Explorer monitoring framework you cannot use the configuration metadata annotations in a Spring bean and you cannot set a Spring bean to record and play back events that pass through it Assembly File In the assembly file you use the bean element to declare a custom Spring bean as a component in the event processor network For example lt bean id TradeListenerBean class com oracle cep example tradereport TradeListener gt lt bean gt 7 2 Event Sink Interfaces You create an event sink to receive events in an EPN and apply logic that responds to the event data A Java class that is an event sink implements one of the interfaces described in this section Each of these interfaces provides methods that the Oracle Event Processing server uses to pass events to the class as the events exit the EPN stage connected upstream from the Java class which is typically a channel Event Beans 7 3 Event Sink Interfaces The interfaces described here provide support for events arriving either as streams or relations However interfaces for relations also support receiving events arr
156. cord parameters Child Element Description dataset name event type list time range Berkeley DB Identifies the recorded data and places it in a directory of this name below the directory specified by the do env path setting in the server config xml file Oracle RDBMS based provider Specifies the database area or schema in which the tables that store the recorded events are created When you configure the Oracle RDBMS based provider you must specify this element Berkeley DB Specifies the event types that are recorded to the event store If this element is not specified then Oracle Stream Explorer records all event types that flow out of the component Oracle RDBMS based provider You must specify this element Specifies the time period during which recording takes place Configure the time period with a start child element to specify a start time and an end child element to specify the end time Express the start and end time as XML Schema dateTime values of the form yyyy mm ddThh mm ss For example to have recording start on January 20 2010 at 5 00 am and end on January 20 2010 at 6 00 pm enter the following lt time range gt lt start gt 2010 01 20T05 00 00 lt start gt lt end gt 2010 01 20T18 00 00 lt end gt lt time range gt For complete details of the XML Schema dat eTime format see http www w3 org TR xmlschema 2 dateTime lexical representation If you do not specify a t
157. ctory gt lt user gt weblogic lt user gt lt password gt welcomel lt password gt lt edn adapter gt 4 7 File Adapter The File adapter reads data from a file into the EPN and converts the data to an event Oracle JDeveloper does not currently provide a component for the File adapter However you can create a File adapter by adding entries to the assembly and configuration files for your Oracle Stream Explorer application Assembly File The path property provides the location of the input file As the adapter reads the data from the input file it converts the incoming data to an event of type OrderArrivalEvent There is an initialDelay of 5000 nanoseconds before the File adapters starts to read the file The downstream OrderArrival channel listens for events of type OrderArrivalEvent lt wlevs adapter id inputAdapter provider file gt lt wlevs instance property name path value wlevs domain home inpOrderArrival txt gt lt wlevs instance property name eventType value OrderArrivalEvent gt lt wlevs instance property name initialDelay value 5000 gt lt wlevs listener ref OrderArrival gt lt wlevs adapter gt Configuration File lt adapter gt lt name gt inputAdapter lt name gt lt adapter gt 4 8 HTTP Publish Subscribe Adapter Use the HTTP Publisher adapter to send JavaScript Object Notation JSON event data out of the EPN to a web based user interface Use the HTTP Subscriber adapt
158. d gt coherence lt enabled gt lt groups gt MyDeploymentGroup ActiveActiveGroupBean_groupl lt groups gt lt cluster gt ocep lt cluster gt server 3 lt server name gt ocep server 3 lt server name gt lt enabled gt coherence lt enabled gt lt groups gt MyDeploymentGroup ActiveActiveGroupBean_group2 lt groups gt lt cluster gt ocep lt cluster gt server 4 lt server name gt ocep server 4 lt server name gt lt enabled gt coherence lt enabled gt lt groups gt MyDeploymentGroup ActiveActiveGroupBean_group2 lt groups gt lt cluster gt 3 Create an Oracle Stream Explorer high availability application For more information see High Availability Applications 4 Add an ActiveActiveGroupBean element to the assembly file as shown lt bean id clusterAdapter class com oracle cep cluster hagroups ActiveActiveGroupBean gt lt bean gt 5 Edit the component configuration file to configure a jms adapter element for the inbound JMS adapters as shown You must set each inbound JMS adapter to listen to a different topic and set session transactedto true lt xml version 1 0 encoding UTF 8 gt lt wlevs config xmlns wlevs http www bea com ns wlevs config application xmlns ha http www oracle com ns cep config cluster gt lt jms adapter gt lt name gt JMS InboundAdapter lt name gt lt event type gt StockTick lt event type gt 18 8 Developing Applications for Event Proces
159. dard Java methods perform JMX operations and shut down the server Testing 1 2 3 14 11 EPN Shell List all deployed Oracle Stream Explorer applications in the running server g listapps com bea wlevs dataservices List all Oracle Stream Explorer libraries This commen lists all of the bundles that are unzipped in the modules directory to run the EPN shell g llistlibs org apache felix bundlerepository org apache felix gogo runtime com oracle cep shell org apache felix gogo command org apache felix gogo shell Install a new application The following example deploys and immediately starts the application g deployapp file Users oepapps hwlloworld jar Undeploy an application g deployapp file Users oepapps hwlloworld jar g undeployapp file Users oepapps hwlloworld jar Send events to an existing Oracle Stream Explorer application by specifying the full name of the channel when you use the send insert update and delete commands This example sends an event to the hel loworldInputChannel in the helloworld application For this to work you must advertise the channel so the EPN shell can find it To advertise the channel set the advertise attribute to true in the assembly file first Assembly file setting lt wlevs channel id helloworldInputChannel event type HelloWorldEvent advertise true gt EPN shell commands g eventl createevent HelloWorldEvent g Seventl message Hi Shell g
160. data structure that defines the data contained in an event Event types are the foundation of the EPN because they determine how event data funnels through the EPN and the operations that can be performed on it When you start your application the first thing to do is to create the event type or types for your EPN because you will need to configure components such as adapters channels relational database tables and big data storage with the appropriate event type Adapters Oracle Stream Explorer provides a selection of input and output adapters to accommodate every type of data that might flow into and out of the EPN For example you can access Java Message Service JMS objects an HTTP Publish Subscribe server and financial market feeds You can also develop your own adapters to integrate systems that are not supported by default See Using Visualizer for Oracle Stream Explorer You configure adapters with an event type and other relevant configuration information The specific configuration depends on whether the adapter handles event input or output and the source of the data For example in the TradeReport application the input CSV adapter configuration specifies the location of the CSV file and values that tell the adapter when to start reading the CSV file and how long to wait between consecutive readings Channels You configure a channel with an event type so that it can transfer events of that type to the next stage in the EPN
161. der ha broadcast gt lt wlevs listener gt lt bean class com bea wlevs example helloworld HelloWorldBean gt lt wlevs listener gt lt wlevs adapter gt Configure the Oracle Stream Explorer high availability input adapter Consider using one of the following example configurations This example shows a high availability input adapter configuration using all defaults The mandatory key is based on all event properties and the event property that the high availability input adapter assigns a time value to is an event property named arrivalTime lt wlevs adapter id myHaInputAdapter provider ha inbound gt lt wlevs instance property name timeProperty value arrivalTime gt lt wlevs adapter gt This example shows a high availability input adapter configuration using all defaults The mandatory key is based on all event properties and the event property that the high availability input adapter assigns a time value to is an event property named arrivalTime Because the events are tuple based events you must specify the event type MyEvent Type using the event Type property lt wlevs adapter id myHaInputAdapter provider ha inbound gt lt wlevs instance property name timeProperty value arrivalTime gt lt wlevs instance property name eventType value MyEventType gt lt wlevs adapter gt This example shows a high availability input adapter configuration where the mandatory key is based on one event pr
162. directory with basedir to indicate the root of the project workspace help Prints help information for the command options and arguments to the command line basedir The root of the project workspace that you set up previous to using the appC utility cp The class path to use to compile the bundle classes config The full path to the component configuration file context The full to the assembly file manifest An optional input manifest file When no manifest file is specified the appC utility generates one Note The underlying BND package used in Oracle Stream Explorer to generate the manifest cannot find reflection usage name The name of the project OSGi bundle name destdir The full path to the directory for the output JAR file The default is basedir srcdir The full path to the source root directory excludedirs A comma separated list of directory names to exclude from the source tree These directories are subdirectories of the source directory root srcdir Examples Compile the input source files and generate the OSGi MANIFEST MF file java jar appC jar cmd generateManifest basedir Assemble and Deploy 13 5 Assemble an OSGi Bundle with bundle sh Create the template generate the MANIFEST MF file and validate the component configuration file and the assembly file java jar appC jar cmd buildALL basedir 13 7 Assemble an OSGi Bundle with bundle sh Oracle Stream E
163. dow length for the broadcast output adapter Oracle Stream Explorer automatically selects one of the Oracle Stream Explorer servers as the primary 17 9 4 Configure Precise Recovery With JMS You configure precise recovery with JMS using the Oracle Stream Explorer high availability input adapter and correlating output adapter 17 28 Developing Applications for Event Processing with Oracle Stream Explorer Configure High Availability Quality of Service This procedure describes how to create the example EPN that Figure 17 12 shows For more information about this Oracle Stream Explorer high availability quality of service see Precise Recovery with JMS Note The JMS destination used by JMS adapters for precise recovery must be topics rather than queues Figure 17 12 Precise Recovery With JMS EPN B IMSInboundAdapter B B Y a B channel channel2 myHalInputAdapter processor myHaCorrelatingAdapter IMSOutboundAdapter clusterCorrelatingOutstream IMSInboundA dapter2 Configure precise recovery with JMS 1 Create a multiserver domain using Oracle Coherence For more information see Administering Oracle Stream Explorer Create an Oracle Stream Explorer application Edit the MANIFEST MF file to add the following Import Package entries com bea wlevs ede api cluster com oracle cep cluster hagroups com oracle cep cluster ha adapter com oracle cep cluster ha api Configure your Oracle Stre
164. down the Oracle Stream Explorer server performs an Oracle Stream Explorer high availability failover to the standby Oracle Stream Explorer server in that ActiveActiveGroupBean group Example 18 3 Precise Recovery With JMS EPN Assembly File lt xml version 1 0 encoding UTF 8 gt lt beans gt lt wlevs event type repository gt lt wlevs event type type name StockTick gt lt wlevs properties gt lt wlevs property name lastPrice type double gt lt wlevs property name symbol type char gt lt wlevs properties gt lt wlevs event type gt lt wlevs event type repository gt lt wlevs adapter id JMSInboundAdapter provider jms inbound gt lt wlevs listener ref myHaInputAdapter gt lt wlevs adapter gt lt wlevs adapter id myHaInputAdapter provider ha inbound gt lt wlevs instance property name keyProperties value sequenceNo gt lt wlevs instance property name timeProperty value inboundTime gt lt wlevs adapter gt lt wlevs channel id channell event type StockTick gt lt wlevs listener ref processorl gt lt wlevs source ref myHaInputAdapter gt lt wlevs application timestamped gt lt wlevs expression gt inboundTime lt wlevs expression gt lt wlevs application timestamped gt lt wlevs channel gt lt wlevs processor id processorl gt lt wlevs listener ref channel2 gt lt wlevs processor gt 18 10 Developing Applications for Event Processing with
165. e Coherence to call into Oracle Stream Explorer and retrieve a reference to the loader or store that is configured for the cache The only difference between configuring a loader or store is that the method name element has a value of get Loader when a loader is used and get Store when a store is being used You pass the cache name to the factory as an input parameter lt cache config gt lt caching scheme mapping gt lt cache mapping gt lt cache name gt myCoherenceCache lt cache name gt lt scheme name gt new replicated lt scheme name gt lt cache mapping gt lt cache mapping gt lt cache name gt myLoaderCache lt cache name gt lt scheme name gt test loader scheme lt scheme name gt lt cache mapping gt lt cache mapping gt lt cache name gt myStoreCache lt cache name gt lt scheme name gt test store scheme lt scheme name gt lt cache mapping gt lt cache mapping gt lt cache name gt cachel lt cache name gt lt scheme name gt new replicated lt scheme name gt lt cache mapping gt lt caching scheme mapping gt lt caching schemes gt lt replicated scheme gt lt scheme name gt new replicated lt scheme name gt lt service name gt ReplicatedCache lt service name gt lt backing map scheme gt lt class scheme gt Cached Event Data 8 5 Configure an Oracle Coherence Caching System and Cache lt scheme ref gt my local scheme lt scheme ref gt lt class scheme gt lt backing map s
166. e programs utils subsystem MYUTIL version 1 0 baseid 600000 endid 600100 lt log_message messageid 600001 severity warning method logNoAuthorization String arg0 java util Date argl int arg2 lt messagebody gt Could not open file 0 on 1 date after 2 number attempts lt messagebody gt lt messagedetail gt The configuration for this application will be defaulted to factory settings Custom configuration information resides in file 0 created on 1 date but is not readable lt messagedetail gt lt cause gt The user is not authorized to use custom configurations Custom configuration information resides in file 0 created on 1 date but is not readable The attempt has been logged to lt cause gt the security log lt action gt The user needs to gain approriate authorization or learn to live with the default settings lt action gt lt log_message gt lt message_catalog gt Simple Text Catalog This example shows the MyUtilLabels xml text catalog with one text definition lt xml version 1 0 gt lt DOCTYPE message_catalog PUBLIC weblogic message catalog dtd http www bea com servers wls90 dtd msgcat dtd gt lt message_catalog gt 110n_package programs utils i18n_package programs utils subsystem MYUTIL version 1 0 lt message gt messageid FileMenuTitle lt messagebody gt File lt messagebody gt lt message gt lt message_catalog gt 12 4 Developing App
167. e the Oracle Stream Explorer server injects an instance of a stream sender class com bea wlevs ede api RelationS Implement this interface to send events as a ource relation or stream At runtime the Oracle Stream Explorer server injects an instance of a relation sender class Extends St reamSource so it also supports stream events The interfaces listed in Table 7 3 are implemented by sender classes your event source class receives from the Oracle Stream Explorer server Table 7 3 Interfaces Implemented by Sender Classes Interface Description com bea wlevs ede api StreamSender Provides a method to send events as a stream 7 6 Developing Applications for Event Processing with Oracle Stream Explorer Event Source Interfaces Interface Description com bea wlevs ede api RelationSender Provides methods to send events as a relation Extends St reamSender so it also support stream events com bea wlevs ede api BatchStreamSen Provides a method with which your code der can send batched events as a stream You might send events batched by time stamp if the downstream stage to which you re sending them is a channel configured for batched events Extends St reamSender so it also provides support for sending events unbatched com bea wlevs ede api BatchRelationS Provides a method to send batched events ender as a relation You can send events batched by time stamp when the downstream stage is a channel configured
168. e Stream Explorer Service annotation to initialize a property in your Java source import com bea wlevs util Service import com bea wlevs ede api EventTypeRepository Service setEventTypeRepository EventTypeRepository etr 3 11 Share Event Types Between Application Bundles Each Oracle Stream Explorer application gets its own Java classloader and loads application classes using that class loader This means that by default one application cannot access the classes in another application However because the event type repository is a singleton service you can configure the repository in one bundle and then explicitly export the event type classes so that applications in separate bundles deployed to the same Oracle Stream Explorer server can use these shared event types The event type names in this case are scoped to the entire Oracle Stream Explorer server instance This means that you will get an exception if you try to create an event type that has the same name as an event type that has been shared from another bundle but the event type classes are different To share event type classes add their package name to the Export Package header of the MANIFEST MF file of the bundle that contains the event type repository you want to share Be sure you deploy the bundle that contains the event type repository before all bundles that contain applications that use the shared event types or you will get a deployme
169. e and a database If the cache will only be reading data including when the backing store is read only you should use a cache loader If the cache will read and write data use a cache store In both cases creating the relationship involves specific configuration and a Java class that knows how to communicate with the data source 8 9 1 Load Cache Data from a Read Only Data Source Using a cache loader you can have a cache in your EPN load data from a read only data source A cache loader is a Java class that loads cache objects into a cache You create a cache loader by writing a Java class that implements the appropriate interfaces to enable the loader class to communicate with the cache Then you configure a cache 8 14 Developing Applications for Event Processing with Oracle Stream Explorer Exchange Data Between a Cache and Another Data Source loader by using the wlevs cache loader child element of the wlevs cache element to specify the bean that does the loading work If the backing store is read write use a cache store instead see Exchange Data with a Read Write Data Source When creating a cache loader you implement interfaces as follows e To load cache data into an Oracle Coherence cache create a class that implements the appropriate Oracle Coherence specific Java interfaces including com tangosol net cache CacheLoader See Example 8 2 for an example e To load cache data into an Oracle Stream Explorer local cache
170. e appropriate Oracle Coherence specific Java interfaces including com tangosol net cache CacheStore See Example 8 4for an example e To exchange cache data with an Oracle Stream Explorer local cache create a class that implements the com bea cache jcache CacheStore interface This interface includes the st ore method that stores the data in the backing store using the passed key Oracle Stream Explorer calls this method when it inserts data into the cache The interface also includes the storeAl1 method for storing a batch of data to a backing store in the case that you have configured asynchronous writes for a cache with the write behind configuration element In Example 8 3 the local Store bean loads events into the cache when the backing store is read write Note that if you specify a cache store in your Spring configuration file you must also specify the corresponding class factory method name in your Coherence cache configuration file For a cache store you specify the get Store method of com bea wlevs cache coherence configuration SpringFactory For example code see Configure an Oracle Coherence Caching System and Cache Example 8 3 Oracle Coherence Cache EPN Assembly File for a Cache Store lt wlevs caching system id caching system id gt lt wlevs cache id myCache advertise false gt lt wlevs caching system ref caching system id gt lt wlevs cache store ref localStore gt lt wlevs cache gt lt bean id localSto
171. e gt lt wlevs event type repository gt JavaBeans also enable you to closely control event type instantiation by implementing an event type builder class For more information on event type builder classes see Control Event Type Instantiation with an Event Type Builder Class Table 3 1 compares JavaBean classes tuples and java util Map classes Table 3 1 Data Types for Event Types Data Type Description Benefits and Limitations JavaBean A Java class written to JavaBean Benefits This type is the best practice conventions In addition to being because it provides the greatest used by logic you write the type s flexibility and ease of use for application accessor get and set methods will logic that handles events You access be used by the Oracle Stream property values directly through Explorer server and Oracle CQL accessor methods A JavaBean class is processor to retrieve and set event more likely to be useful when integrating property values your Oracle Stream Explorer application with other systems For control over how the type is instantiated you can implement an event type builder class Limitations Requires writing a JavaBean class rather than simply declaring the event type in a configuration file Oracle COL does not support JavaBean properties in GROUP BY PARTITION BY and ORDER BY although you can work around this by using an Oracle CQL view 3 2 Developing Applications for Event Processing with Oracle S
172. e gt lt jndi provider url gt t3 ppurich pc 7001 lt jndi provider url gt Scalable Applications 18 9 Partition an Incoming JMS Event Stream lt destination jndi name gt Topicl lt destination jndi name gt lt session transacted gt true lt session transacted gt lt jms adapter gt lt jms adapter gt lt name gt JMS InboundAdapter2 lt name gt lt event type gt StockTick lt event type gt lt jndi provider url gt t3 ppurich pc 7001 lt jndi provider url gt lt destination jndi name gt Topic2 lt destination jndi name gt lt session transacted gt true lt session transacted gt lt jms adapter gt lt jms adapter gt lt name gt JMSOutboundAdapter lt name gt lt event type gt StockTick lt event type gt lt jndi provider url gt t3 ppurich pc 7001 lt jndi provider url gt lt destination jndi name gt Topic2 lt destination jndi name gt lt session transacted gt true lt session transacted gt lt jms adapter gt lt wlevs config gt 8 Deploy your application to the deployment group of your multiserver domain At runtime each Oracle Stream Explorer server configures its instance of the application with the message selector that corresponds to its ActiveActiveGroupBean notification group This partitions the JMS topic so that each instance of the application processes a subset of the total number of messages in parallel If the active Oracle Stream Explorer server in an Act iveAct iveGroupBean group goes
173. e messages that your application displays to the user e Locale message catalogs A collection of locale specific messages that correspond to a top level log message catalog or a simple text catalog that contains the English version of the messages There are corresponding locale specific catalogs with one catalog for each additional supported locale The top level English version catalog has all of the information needed to define the message The locale specific catalogs contain only the message ID the date changed and the translation of the message for the specific locale You create your own catalog of log or simple text messages and use Oracle WebLogic utilities to generate Java classes that have logging methods You import the Java classes into your application code and implement your application code to supply runtime values to the logging methods The log messages generated by the logging Internationalization 12 1 Message Catalogs methods are integrated with and treated in the same way as log messages that are generated by the Oracle Stream Explorer server The message catalog files are defined by one of the following XML document type definition DTD files e msgcat dtd Describes the syntax of top level default catalogs e 110n_msgcat dtd Describes the syntax of locale specific catalogs The DTDs are stored in Oracle Middleware wlevserver modules com bea core il8n generator_VERSION jar VERSION points to a particu
174. e repository Events and Event Types 3 11 Create and Register a Map Event Type public void setEventTypeRepository EventTypeRepository etr etr_ etr Called by the server to pass in the event type instance public void onInsertEvent Object event throws EventRejectedException Get the event type for the current event instance EventType eventType etr_ getEventType event Get the event type name String eventTypeName eventType getTypeName Get the event property names String propNames eventType getPropertyNames See if property you re looking for is present if eventType isProperty fromRate Get property value Object propValue eventType getProperty fromRate getValue event Throw com bea wlevs ede api EventRejectedException to have an exception propagated up to senders Other errors will be logged and dropped 3 8 3 Use a Tuple Event Type Instance in Oracle CQL Code The following Oracle CQL rule shows how to reference the CrossRateEvent ina SELECT statement FxQuoteSt ream is a channel with the CrossRateEvent event type lt query id FindCrossRatesRule gt lt CDATA select a price b price 0 05 as internalPrice a fromRate as crossRatel b toRate as crossRate2 from FxQuoteStream range 1 as a FxQuoteStream range 1 as b where NOT a price IS NULL and NOT b price IS NULL and a toRate b fromRate gt lt query gt
175. e that contains the rules and decision function you want to use The decision function element specifies the name of the OBR decision function you want to use lt processor gt lt name gt helloworldProcessor lt name gt lt rules gt lt query id helloworldRule gt lt CDATA select from helloworldInputChannel range 10 slide 5 J gt select from helloworldInputChannel now lt query gt 4 18 Developing Applications for Event Processing with Oracle Stream Explorer QuickFix Adapter lt rules gt lt processor gt lt obr adapter gt lt name gt OBRAdapter lt name gt lt dictionary url gt file helloworld rules lt dictionary url gt lt decision function gt handlerl lt decision function gt lt obr adapter gt 4 13 QuickFix Adapter The QuickFix Adapter is a full featured messaging engine for handling the real time electronic exchange of securities transactions according to the Financial Information eXchange FIX standard The QuickFix adapter listens for FIX messages converts the FIX messages to Oracle Stream Explorer events and sends the events to the next stage for processing See Getting Started with Event Processing for Oracle Stream Explorer for an example application The QuickFix adapter supports all of the configuration data that the underlying QuickFIX engine provides For information about FIX configuration data see the QuickFIX J User Manual at http www quickfixj org documentation Note
176. e the query in parallel this is needed to guarantee the correct result considering the ordering constraint Some query semantics in themselves also constrain the query to ordered processing Such queries will be executed serially regardless of whether you specify support for parallel execution Also the ISt ream RSt ream and DSt ream operators maintain the state of their operand for processing making it necessary for the CQL processor to synchronize threads in order to execute the query Note that the CQL processor always respects the semantic intention of your query In cases where the ordering constraint attribute would change this intention the attribute is coerced to a value that keeps the intention intact If you re using the partitioning expression attribute keep in mind that the attribute supports a single expression only Entering multiple property names for the value is not supported 6 14 Developing Applications for Event Processing with Oracle Stream Explorer Fault Handling 6 7 Fault Handling You can write code to handle faults that occur in code that does not have an inherent fault handling mechanism This includes Oracle CQL code and multithreaded EPN channels By default the COL language has no mechanism for handling errors that occur as does Java with its try catch structure To handle faults that occur in CQL you can write a fault handler then connect the handler to the EPN stage for which it handles faults suc
177. e to specify the MANIFEST MF file you created in the previous step rather than the default manifest file You can name the JAR file anything you want In the Oracle Stream Explorer examples the name of the JAR file is a combination of Java package name and version such as com bea wlevs example helloworld_1 0 0 0 jar Consider using a similar naming convention to clarify which bundles are deployed to the server 10 If your application depends on foreign stages see Reference Foreign Stages 13 7 2 Create the MANIFEST MF File The structure and contents of the MANIFEST MF file is specified by the OSGi Framework Although the value of many of the headers in the file is specific to your application or business many of the headers are required by Oracle Stream Explorer In particular the MANIFEST MF file defines the following e Application name Specified with the Bundle Name header e Symbolic application name Specified with the Bundle SymbolicName header Many of the Oracle Stream Explorer tools such as the wlevs Admin utility and JMX subsystem use the symbolic name of the bundle when referring to the application e Application version Specified with the Bundle Version header e Imported packages Specified with the Import Package header Oracle Stream Explorer requires that you import the following packages at a minimum Import Package com bea wlevs adapter defaultprovider version 11 1 1 Assemble
178. ecord speed A value of 0 5 means that events will be played back at half the speed Specifies whether to playback events again after the playback of the specified time interval completes Valid values are true and false Default value is false A value of true means that the repeat of playback continues an infinite number of times until it is deliberately stopped False means that events are played back once If specified Oracle Stream Explorer uses a stream when playing back events from the event store This element specifies the size of the stream with non zero values indicating asynchronous writes Default value is 1024 Debug with Event Record and Playback 15 9 Start and Stop the Record and Playback of Events Child Element Description max threads If specified Oracle Stream Explorer uses a stream to play back events from the event store This element specifies the maximum number of threads to use to process events for the stream This value has no effect when max size is 0 The default value is 1 15 8 Start and Stop the Record and Playback of Events After you configure the record and playback functionality for the components of an application and you deploy the application to Oracle Stream Explorer the server starts to record events only when you have configured explicit star and stop information in the configuration file For example if you included the following element in a component configuration then r
179. ecording starts on January 20 2010 at 5 00 am lt time range gt lt start gt 2010 01 20T05 00 00 lt start gt lt end gt 2010 01 20T18 00 00 lt end gt lt time range gt To enable the recording and playback of events use Oracle Stream Explorer Visualizer or wlevs Admin Once recording and playback are enabled they start and stop according to their configuration settings For more information see e Using Visualizer for Oracle Stream Explorer e Administering Oracle Stream Explorer Visualizer and wlevs Admin use managed beans MBeans to dynamically start and stop event recording and playback and manage the event store configuration A managed bean is a Java bean that provides a Java Management Extensions JMX interface JMX is the Java EE solution for monitoring and managing resources on a network You can create your own administration tool and use JMX to manage event store functionality with com bea wlevs management configuration StageMBean For more information see e Administering Oracle Stream Explorer e Java API Reference for Oracle Stream Explorer 15 10 Developing Applications for Event Processing with Oracle Stream Explorer Part Ill Tune and Scale Part III contains the following chapters e Performance Tuning e High Availability Applications e Scalable Applications 16 Performance Tuning This chapter describes techniques for improving Oracle Stream Explorer application performan
180. ect the Oracle Stream Explorer application to its downstream client The high availability output adapter in the primary also communicates with the corresponding high availability output adapters in each secondary and depending on the high availability quality of service you choose can instruct the secondary output adapters to trim their in memory queues of output events For information about the high availability output adapters see Buffering Output Adapter Broadcast Output Adapter and Correlating Output Adapter Which output adapter you choose is determined by the high availability quality of service you choose See Choose a Quality of Service Option Figure 17 5 shows a simplified EPN with all possible high availability adapters in place The figure shows no channels and one processor High Availability Applications 17 5 High Availability Adapters Figure 17 5 High Availability Adapters in the EPN InputAdapter HAInputAdapter Processor HAOutputAdapter OutputAdapter a Server 2 Secondary I Queue Trimming Messages Optional Key Timestamp Input Messages Streams InputAdapter HaAInputAdapter Processor HAOutputAdapter OutputAdapter Output Streams Server1 Primary Mutti Server Domain Deployment Group and Notification Group 17 5 1 High Availability Input Adapter Each event is associated with a point in time at which the event occurred There are two differ
181. ee Scalable Applications 16 2 High Availability Performance Tuning When creating high availability applications for deployment to multiserver domains consider the following performance tuning options Host configuration To maximize high availability performance ensure that all hosts in the multiserver domain are configured with equivalent processing capacity similar number and type of CPUs and that all hosts have sufficient memory and disk for the needs of the application High availability input adapter and quality of service The Oracle Stream Explorer high availability input adapter is applicable to all high availability quality of service options However because the high availability input adapter increases performance overhead it is not appropriate for some high availability quality of service options such as those described in Simple Failover and Simple Failover with Buffering If you Performance Tuning 16 1 High Availability Performance Tuning are using application time from the event then you do not need to use the input adapter Application time from the event is always preferable from a performance standpoint High availability input adapter configuration Consider increasing the bat ch size to reduce the amount of time the primary server spends broadcasting event messages and to reduce the amount of time the secondary servers spend processing these messages Increasing the bat ch size can increase the likelihood o
182. eference information about the elements see Schema Reference for Oracle Stream Explorer 14 2 6 Event Inspector API You can use the Event Inspector API to inject and trace events The Oracle Stream Explorer API provides the Event InspectorMBean interface that you can implement to control the event tracing and injection behavior Only the administrator and monitor administrator roles can invoke the startInject stopInject startTrace and stopTrace methods See Java API Reference for Oracle Stream Explorer for information about the Event InspectorMBean interface and its methods Once you implement the Event Inspect orMBean interface you can call its methods from your application to inject and trace events as follows Inject Events 1 Get an instance of com bea wlevs eventinspector management EventInspectorMBean from the server through JMX 2 Call the Event InspectorMBean startInject method to start event injection on the stage specified in the server config xml file configuration for an HTTP publish Subscribe channel as explained in HTTP Publish Subscribe Channel and Server 3 Publish events to the specified HTTP publish subscribe channel 4 Use the Event InspectorMBean isInjecting method to verify that event injection has started on the stage 5 Call the Event InspectorMBean stopInject method to stop event injection Testing 1 2 3 14 9 EPN Shell Trace Events 1 Get an instance of com bea wlevs
183. element id attribute defines the view name A top level SELECT statement that you create in a view element is called a view Note Subqueries are used with binary set operators such as union union all and minus You must use parentheses in the subqueries so that the right precedence is applied to the query 6 8 Developing Applications for Event Processing with Oracle Stream Explorer CQL Aggregations The following example shows view v1 and query q1 on the view The view selects from stream S1 of xmltype stream elements The view v1 uses the XMLTABLE clause to parse data from the xmlt ype stream elements with XPath expressions The query q1 selects from view v1 as it would from any other data source The XMLTABLE clause also supports XML name spaces An xmltype stream contains XML data With the Oracle CQL XMLTABLE clause you can parse data from an xml1t ype stream into columns using XPath expressions and access the data by column name XPath expressions enable you to navigate through elements and attributes in an XML document Note The data types in the view s schema match the data types of the parsed data in the COLUMNS clause lt view id vl schema orderId LastShares LastPrice gt lt CDATA SELECT X OrderId X LastShares X LastPrice FROM S1 XMLTABLE FILL PASSING BY VALUE Sieb asn COLUMNS OrderId char 16 PATH fn data ID LastShares integer PATH fn data LastShares LastPrice
184. emID itemID for PriceTarget target s_entriesToLoad q setParameter itemID target getItemID List lt PriceTarget gt targetList g getResultList if targetList size 0 System out println Persisting target target getItemID m_entityMgr persist target else System out println Found target target getItemID m_entityMgr getTransaction commit finally if m_entityMgr getTransaction isActive m_entityMgr getTransaction rollback public void destroy if m_entityMgr null m_entityMgr close m_entityMgr null if m_entityMgrFactory null m_entityMgrFactory close m_entityMgrFactory null private static void setUpEntriesToLoad smith ipad2 400 PriceTarget target new PriceTarget target setItemID ipad2 target setTargetPrice 400 s_entriesToLoad add target doe kindle 100 EclipseLink JPA and Oracle Coherence 9 9 JPA Coherence Example target new PriceTarget target setItemID kindle target setTargetPrice 100 s_entriesToLoad add target walker rebel 400 target new PriceTarget target setItemID rebel target setTargetPrice 400 s_entriesToLoad add target williams laskol320 25 target new PriceTarget target setItemID lasko1320 target setTargetPrice 25 s_entriesToLoad add target 9 3 2 4 SaleEvent java package com oracle cep sample import
185. ent approaches to generating event timestamps application timestamps and system timestamps see Channels for information about application and system time stamps Application time means that a time value is assigned to each event externally by the application before the event enters a CQL processor System time means that a time value is associated with an event automatically by Oracle Stream Explorer when it arrives at a CQL processor Application time is generally the best approach for applications that need to be highly available The application time is associated with an event before the event is sent to Oracle Stream Explorer so it is consistent across active primary and secondary instances System time can cause application instances to generate different results because the time value associated with an event can be different on each instance due to system clocks not being synchronized Using system time is not a problem for applications whose CQL queries do not use time based windows Applications that use only event based windows depend only on the arrival order of events rather than the arrival time so system time can be used in this case For applications that use time based windows and do not have externally generated application time stamps the optional Oracle Stream Explorer high availability input adapter can be used to provide a consistent time value across all servers The input adapter instance on the primary server assigns a
186. ent source is a JavaBean or Java class that sends events If your deployment context and the features you want to use are based on Spring use a Spring bean Otherwise use an event bean Table 7 1 lists the features provided by event beans and Spring beans Event Beans 7 1 Event Beans and Spring Beans Table 7 1 Comparison of Event Beans and Spring Beans Bean Type Description Event bean Useful as an EPN stage to actively use the capabilities of the Oracle Stream Explorer server container An event bean e Isa type of Oracle Stream Explorer EPN stage e Can be monitored by the Oracle Stream Explorer monitoring framework e Can make use of the configuration metadata annotations e Can be set to record and play back events that pass through it e Can participate in the Oracle Stream Explorer server bean life cycle by specifying methods in its XML declaration rather than by implementing Oracle Stream Explorer server API interfaces Spring bean Useful for legacy integration to Spring A Spring bean e Is useful if you have a Spring bean you want to add to an EPN e Is nota type of Oracle Stream Explorer EPN stage e Cannot be monitored by the Oracle Stream Explorer monitoring framework e Cannot use the configuration metadata annotations e Cannot be set to record and play back events that pass through it 7 1 1 Threading Behavior Event beans are executed in parallel when they implement either the Runnable or the Runna
187. ent type HelloWorldEvent gt lt wlevs listener ref helloworldProcessor gt lt wlevs source ref myHalInputAdapter gt lt wlevs application timestamped gt lt wlevs expression gt arrivalTime lt wlevs expression gt lt wlevs application timestamped gt lt wlevs channel gt Configure the Oracle Stream Explorer high availability broadcast output adapter Consider using one of the following example configurations This example shows a broadcast output adapter configuration using all defaults The mandatory key is based on all event properties key values are non monotonic do not increase continually and total order unique lt wlevs adapter id myHaSlidingWindowAdapter provider ha broadcast gt lt wlevs listener gt lt bean class com bea wlevs example helloworld HelloWorldBean gt lt wlevs listener gt lt wlevs adapter gt This example shows a broadcast output adapter configuration where the mandatory key is based on one event property named t imeProperty key values are monotonic they do increase continually and not total order not unique lt wlevs adapter id myHaSlidingWindowAdapter provider ha broadcast gt lt wlevs listener gt lt bean class com bea wlevs example helloworld HelloWorldBean gt lt wlevs listener gt lt wlevs instance property name keyProperties value timeProperty gt lt wlevs instance property name monotonic value true gt lt wlevs instance property name to
188. er and a high availability correlating output adapter before each output adapter To increase scalability you can also use the cluster groups bean with high availability quality of service For more information see e Configure Precise Recovery With JMS e Partition an Incoming JMS Event Stream 17 8 Design Applications for High Availability Although you can implement Oracle Stream Explorer high availability declaratively to fully benefit from the high availability quality of service you choose you must design your Oracle Stream Explorer application to take advantage of the high availability options that Oracle Stream Explorer provides When you design your application for high availability consider the primary use case design patterns and Oracle CQL query restrictions discussed here 17 8 1 Primary High Availability Use Case You can adapt high availability options to various Oracle Stream Explorer application designs but in general Oracle Stream Explorer high availability is designed for the following use case 17 12 Developing Applications for Event Processing with Oracle Stream Explorer Design Applications for High Availability An application receives input events from one or more external systems The external systems are publish subscribe style systems that allow multiple instances of the application to connect simultaneously and receive the same stream of messages The application does not update any external sys
189. er factory is registered as shown in bold lt wlevs event type repository gt lt wlevs event type type name ForeignExchangeEvent gt lt wlevs class gt com bea wlevs example fx OutputBeanSForeignExchangeEvent lt wlevs class gt lt wlevs property name builderFactory gt lt bean id builderFactory class com bea wlevs example fx ForeignExchangeBuilderFactory gt lt wlevs property gt lt wlevs event type gt lt wlevs event type repository gt Events and Event Types 3 17 Control Event Type Instantiation with an Event Type Builder Class 3 18 Developing Applications for Event Processing with Oracle Stream Explorer 4 Adapters Adapters manage data entering and leaving the EPN Oracle Stream Explorer provides a number of different kinds of inbound and outbound adapters to handle different types of data such as CSV RMI and HTTP All adapters have a provider property that is a reference to the OSGi registered adapter factory service and defines the type of data that the adapter handles Inbound adapters receive event data from a data stream entering the EPN assign the data to an event according to the event type and send the data to the next stage in the EPN Outbound adapters receive events processed by the EPN convert the events to their output form and send the converted data to an output data source such as another EPN a non EPN application a CSV file or a web page This chapter includes the following
190. er interface implementation that is the builder static class ForeignExchangeBuilder implements EventBuilder A Map instance to hold properties until the event type is instantiated private Map lt String Object gt values new HashMap lt String Object gt 10 Called by the server to put an event type property Values from the map 3 16 Developing Applications for Event Processing with Oracle Stream Explorer Control Event Type Instantiation with an Event Type Builder Class will be used to instantiate the event type public void put String property Object value throws IllegalStateException values put property value Called by the server to create the event type instance once property values have been received public Object createEvent return new ForeignExchangeEvent String values get symbol Double values get price String values get fromRate String values get toRate 3 12 2 An Event Type that Uses an Event Type Builder When you register the event type in the EPN assembly file use the lt wlevs property name builderFactory gt child element of the wlevs event type element to specify the name of the event type builder class The hard coded builderFactory value of the name attribute alerts Oracle Stream Explorer that it should use the specified factory class rather than its own default factory when creating instances of this event For example in the FX example the build
191. er to accept JavaScript Object Notation JSON event data entering the EPN JSON event data comes from an HTTP server where user actions generate events The HTTP Publish Subscribe server in Oracle Stream Explorer is based on the Bayeux protocol that is proposed by the cometd project The Bayeux protocol defines a contract between the client and the server for communicating with asynchronous messages over HTTP You can create a remote or a local HTTP Publisher adapter and a remote HTTP Subscriber adapter Whether an HTTP adapter is local or remote is determined by the local or remote URL you supply to the required lt server url gt child element Adapters 4 9 HTTP Publish Subscribe Adapter Custom Converter Bean The best way to create HTTP publish and subscribe adapters is to use Oracle JDeveloper Note Byte arrays are not supported as property types in event types used with the HTTP Publish and Subscribe adapters Assembly File lt wlevs adapter id http pub adapter provider httppub gt lt wlevs adapter id http sub adapter provider httpsub gt Configuration File For every local and remote adapter provide a URL to the server in the server url property The server can be an Oracle Stream Explorer server a WebLogic Server instance or any third party HTTP Publish Subscribe server For every local adapter for publishing add a server context path element to specify the path to the local HTTP Publish Subsc
192. erver rejoins the multiserver domain if your application is an Oracle Stream Explorer high availability Type 1 application an application that must generate exactly the same sequence of output events as existing secondaries then it must wait the warm up window length time you configure for the Oracle Stream Explorer high availability output adapter before it is available as a secondary To implement this high availability quality of service you configure your EPN with a high availability input adapter after each input adapter and a high availability broadcast output adapter before each output adapter For more information see Configure Light Weight Queue Trimming 17 7 4 Precise Recovery with JMS The precise recovery with JMS high availability quality of service is characterized by a high performance overhead slower recovery time and maximum data integrity no missed events and no duplicate events during failover This high availability quality of service is compatible with only JMS input and output adapters In the precise recovery with JMS high availability quality of service the focus is not on transactional guarantees along the event path for a single server but on guaranteeing a single output from a set of servers To achieve guarantee secondary servers listen over JMS to the event stream being published by the primary As Figure 17 7 shows this incoming event stream is a source of reliable queue trimming messages that the se
193. erver url gt http HOST PORT PATH lt pubsub server url gt lt event inspector gt HOST The host name or IP address of the remote Oracle Stream Explorer server PORT The remote Oracle Stream Explorer server net io port as defined in the remote Oracle Stream Explorer server file Default 9002 PATH The value of the htt p pubsub element path child element as defined in the remote Oracle Stream Explorer server file Given the http pubsub configuration that the example shows a valid pubsub server url would be as follows http remotehost 9002 pubsub The pubsub server name value myPubSub is the value of the htt p pubsub element name child element as defined in the local Oracle Stream Explorer server file as the following example shows lt http pubsub gt lt name gt myPubSub lt name gt Testing 1 2 3 14 7 Event Inspector Service lt path gt pubsub lt path gt lt pub sub bean gt lt server config gt lt supported transport gt lt types gt lt element gt long polling lt element gt lt types gt lt supported transport gt lt publish without connect allowed gt true lt publish without connect allowed gt lt server config gt lt channels gt lt channels gt lt pub sub bean gt lt http pubsub gt 14 2 4 Inject Events After you configure the Event Inspector service HTTP pub sub server you can use Event Inspector clients to inject events To configure event injection you can use the Orac
194. es the RSTREAM operator to select all events in the input stream wait for two events to arrive in the relation and put the two events from the relation into the output stream RSTREAM SELECT FROM StockTradeIStreamChannel ROWS 2 The following configuration file entry shows the RSTREAM operator 6 6 Developing Applications for Event Processing with Oracle Stream Explorer Queries lt processor gt lt rules gt lt query id rule2 lt CDATA RSTREAM SELECT FROM StockTradeIStreamChannel ROWS 2 gt lt query gt lt rules gt lt processor gt 6 3 2 3 NOW and Last Event Windows A NOW window to contain the event that happened at the last tick of the system With the NOW operator the last input event can be deleted in the next time tick the new NOW so you might not have captured what you want If you truly the last input event use a last event window The following example shows how to construct a NOW window SELECT FROM StockTradelIStream NOW The following configuration file entry shows the NOW operator lt processor gt lt rules gt lt query id rule2 lt CDATA ISTREAM SELECT FROM StockTradeIStreamChannel NOW gt lt query gt lt rules gt lt processor gt A last event window captures the last event received The following example shows how to construct a last event window SELECT FROM StockTradelIStream ROWS 1 The following configuration file entry shows a last event window
195. esesees 3 8 3 7 3 Create a JavaBean Event Type Programmatically s snsssosseseessessessessesresnsnsissessessenness 3 9 EA E OET OS E E E E E E 3 9 3 8 Create and Register a Tuple Event Type ssse sesssessserississessentensisresnetersissisnentennissesnenreesesresnes 3 10 3 8 1 Create a Tuple Event Type in the Assembly File ccecessesesecessesseseseseneneenees 3 11 3 8 2 Use a Tuple Event Type in Java Code ccccccccecccsesteteeseeceseseseecenesesesnsnsneseseeeeneseseseeneney 3 11 3 8 3 Use a Tuple Event Type Instance in Oracle CQL Code ceccceescccessesseeesesessesesees 3 12 3 9 Create and Register a Map Event Type svosesiisseon r nioi ora ana a e eii 3 12 3 10 Access the Event Type Repository ccccccsceseesesesceceseseseensesesesesnesssesescecessseseansnenesesesnenenesees 3 14 3 101 EPN Assembly Pile scs 2 coscs stots cess nea S eE a aa E eE tee ei t 3 14 3 10 2 Spring DM ServiceReference Annotation cccccceseesesesssssssesesesssssssesesesssseesees 3 15 3 10 3 Oracle Stream Explorer Service Annotation ccccceeeseeessssssesesesssssssesesssssssesesees 3 15 3 11 Share Event Types Between Application Bundles ss ssssssessssessertersississestensissesnenrensessesses 3 15 3 12 Control Event Type Instantiation with an Event Type Builder Class cccccseeeeseee 3 15 3 12 1 Implement an Event Type Builder Class cccccccsssseeeseeesssssesesesessssseseseseseseeesees 3 16 3 12 2 An Event Type t
196. essage import javax jms Session import javax jms TextMessage import java util ArrayList import java util List public class MessageConverter implements InboundMessageConverter OutboundMessageConverter public List convert Message message throws MessageConverterException JMSException TestEvent event new TestEvent TextMessage textMessage TextMessage message event setString_1 textMessage getText List events new ArrayList 1 events add event return events public List lt Message gt convert Session session Object inputEvent throws MessageConverterException JMSException TestEvent event TestEvent inputEvent TextMessage message session createTextMessage 4 16 Developing Applications for Event Processing with Oracle Stream Explorer Oracle Business Rules Adapter Text message event getString_l i List lt Message gt messages new ArrayList lt Message gt j messages add message return messages 3 Specify the converter in your application EPN assembly file e Register the converter class using a bean element e Associate the converter class with the JMS adapter by adding a wlevs instance property with name set to converterBean and ref set to the id of bean The following example shows how to register and associate the converter class lt bean id myConverter class com customer MessageConverter gt lt wlevs adapter id jmsOutbound provider jms outbo
197. et on the connection factory administratively with the console You should have a dedicated connection factory configured for each adapter instance that is using durable subscribers 3 Set the following three jms adapter properties e destination type to TOPIC e durable subscription to true e durable subscription name toa unique subscription identifier 4 10 3 Outbound Adapter Configuration The outbound JMS adapter converts events into a JMS map message and sends the JMS message to a JMS destination You can also customize this conversion by writing your own Java class to specify exactly how you want the event types to be converted into outgoing JMS messages See Customizing Oracle Stream Explorer Assembly File lt wlevs adapter id jms outbound adapter provider jms outbound gt Configuration File The JMS Outbound adapter configuration is almost the same as the JMS Inbound adapter configuration The outbound adapter specifies a JMS destination and provides a user name and password to access the JMS destination This session is transactional and non persistent lt jms adapter gt lt name gt jms outbound adapter lt name gt lt event type gt TradeEvent lt event type gt lt jndi provider url gt t3 localhost 7101 lt jndi provider url gt lt jndi factory gt weblogic jndi WLInitialContextFactory lt jndi factory gt lt connection jndi name gt Topic lt connection jndi name gt lt dest inat ion jndi name gt Que
198. eventinspector management EventInspectorMBean from the server through JMX 2 Call the EventInspectorMBean startTrace method to start event tracing on the stage specified in the server config xml file configuration for an HTTP publish subscribe channel as explained in HTTP Publish Subscribe Channel and Server 3 Use the Event Inspect orMBean isTracing method to verify that event tracing has started on the HTTP Publish Subscribe channel 4 Call the Event InspectorMBean stopTrace method to stop event tracing 14 3 EPN Shell The EPN shell provides shell commands for testing Oracle Stream Explorer applications See EPN Command Interface for information about how to perform EPN operations programmatically The EPN shell extends the Apache Felix Gogo shell which provides a standard shell command prompt for OSGi frameworks See the Apache Felix Gogo documentation at http felix apache org documentation subprojects apache felix gogo html To start the server in the EPN shell go to Oracle Middleware my_oep user_projects domains lt my_domain gt lt server gt and start the Oracle Stream Explorer server in the EPN shell as follows UNIX startwlevs sh shell gi Windows startwlevs cmd shell gi When the EPN shell starts you see the g prompt Type help to display a list of all of the commands The commands specific to EPN are prefixed by epn for example epn channel g help To display help about a p
199. evs channel id LocalPartitionChannel event type StockEvent is local partitioner true max threads 3 gt lt wlevs instance property name partitionByEventProperty value symbol gt lt wlevs channel gt Important Channel Properties The local partition channel has the following important properties e IS LOCAL PARTITIONER Defines channel to be a local partitioning channel e MAX THREADS Specifies the degree of parallelism e MAX SIZE Determines the maximum number of buffered events per partition e PARTITIONING ATTRIBUTE Specifies the attribute of the stream which will be used to partition the stream Example 18 2 Configuration lt processor gt lt name gt StockAggregateProcessor lt name gt lt rules gt lt query id helloworldRule gt lt CDATA select count as symbolCount symbol from LocalPartitionChannel group by symbol gt lt query gt lt rules gt lt processor gt 18 2 Partition an Incoming JMS Event Stream You can add the Act iveAct iveGroupBean class to the assembly file to partition an incoming JMS event stream by a selector in a multiserver domain e Configure Partitioning without High Availability e Configure Partitioning with High Availability 18 2 1 Configure Partitioning without High Availability 1 Create a multiserver domain In this example the deployment group name is MyDeployment Group See Administering Oracle Stream Explorer 2 Configure the Ora
200. exposure of financial portfolio and thus analyze the risks 5 7 2 Local Partitioning Channel Local Partitioning is a technique that helps in partitioning the events within a distributed flow In a local partition channel you must use an ordered set of event properties as the partition criteria The channel partitioning is present in the management console as a part of the channel and the channel configuration See Figure 5 2 As local partitioning aims at improving the input throughput if you want to measure the speed rate you must measure the events per second that an adapter is able to send to the processor Note You must choose the max threads value appropriately based on the hardware capacity of the machine you are using 5 6 Developing Applications for Event Processing with Oracle Stream Explorer Distributed Flows Figure 5 2 EPN with Oracle CQL Processor and Downstream Channel My EventPartitioner 3 LocalPartitionChannel OutputChannel StockAdapter StockAggregateProcessor Security Secure Sockets Layer SSL is used to secure network traffic between the distributed EPN nodes Configuration You must configure the Oracle CQL Processor to support local partitioning See Define a Local Partition Channel and Configure an Oracle CQL Processor for Parallel Query Execution Examples Here are a few examples of a simple EPN Example 5 1 EPN Example 1 An event is defined as the relation P of any pair PN PV
201. f missed and duplicate events when the primary fails before broadcasting an event message with a large number of events Broadcast output adapter configuration Decrease the trimming interval to reduce the amount of time the primary server spends broadcasting trimming messages and to reduce the amount of time the secondary servers spend processing these messages Decreasing the trimming interval may increase recovery time as the new primary server s in memory queue will be more out of date relative to the old primary Oracle Coherence performance tuning options When you configure Oracle Coherence in a high availability architecture consider the following options e Increase the Oracle Coherence heartbeat time out machine frequency to reduce the number of heartbeats before failure See Oracle Coherence Developer s Guide at http download oracle com docs cd E15357_01 coh 360 e15723 tune_perftune htm e Implement the Oracle Coherence Portable Object Format POF for serialization to improve messaging performance POF is a language agnostic binary format that was designed to be very efficient in both space and time Using POF instead of Java serialization can greatly improve performance 16 2 Developing Applications for Event Processing with Oracle Stream Explorer 17 High Availability Applications High availability is critical to Oracle Stream Explorer applications because they continuously monitor streaming data Oracle Stream
202. faces and classes for managing JMX communications in a high availability environment com oracle cep cluster ha adapter runtime package provides interfaces and class implementations for managing JMX interfaces to other high availability interfaces com oracle cep cluster ha api package provides interfaces and classes for simple fail over functionality com oracle cep cluster hagroups package provides interfaces and classes for creating event beans and adapter that listen for property group membership changes make the changes available and enable subscriptions to broadcast group members com oracle cep cluster hagroups runtime package provides interfaces and classes to get notification group information Testing and Utility Tools Oracle Stream Explorer provides different ways to test your application depending on what and how you want to test See Testing 1 2 3 Packages com bea wlevs eventinspector management package provides interfaces and classes for managing event tracing and injection Introduction to Application Development 1 11 Spring Framework e com oracle cep shell package provides interfaces and classes for programmatically invoking commands for testing Oracle Stream Explorer applications e com bea wlevs util package provides interfaces and classes for marking methods as requiring an OSGi service reference getting and setting error messages parsing parameters returning OSGi importer services cardinality a
203. figuration file settings configure an Oracle Coherence caching system and cache for an Oracle CQL processor The cache uses an event type to specify the key properties for locating table rows in the relational database This caching system is advertised which means other applications can access the data in its caches 8 2 1 Assembly File The assembly file settings configure the caching system and cachel The value type setting is the event type into which you want to load the database values This cache is advertised lt wlevs cache id cachel value type TradeReport advertise true gt lt wlevs caching system ref coherence caching system gt lt wlevs cache gt lt wlevs caching system id coherence caching system provider coherence gt Note When you change the id setting for a coherence cache in the EPN diagram the id changes in the assembly file and in the coherence cache file However if you change the id setting in the assembly file source editor the id changes in the assembly file only In this case you must manually change the cache name setting in the coherence cache to match the id setting in the assembly file You also have to change all references to that cache When the cache is advertised a component in the EPN of an application in a separate bundle can reference the advertised cache The following example shows how a processor in one bundle can use the cache source element to reference a cache
204. filter Name StockDs public void setDataSourceService DataSourceService dss initStockTable dss getDataSource Introduction to Application Development 1 13 OSGi Service Platform 1 14 Developing Applications for Event Processing with Oracle Stream Explorer 2 Application and Resource Configuration An Oracle Stream Explorer EPN has two types of configuration files assembly files and component configuration files The assembly file is a context file that describes the EPN diagram stages and structure The configuration file describes component configuration and the dynamic parameters of the EPN stages Dynamic parameters are parameters that can be changed at runtime through the Oracle Stream Explorer Visualizer or programmatically through the JMX APIs This chapter includes the following sections e Application Configuration e Assembly File Structure e Component Configuration File Structure e Component and Server Configuration e Resource Access Configuration 2 1 Application Configuration Oracle Stream Explorer application configuration settings are stored in XML files that are based on standard schemas When you install Oracle Stream Explorer the XSD files for the schemas are installed in the Oracle Middleware oep xsd directory By default Oracle JDeveloper generates one assembly file named lt Project Name gt context xml and one default configuration file named processor xml An application can h
205. float PATH fn data LastPx as X gt lt view gt lt query id ql gt lt CDATA IStream select orderld sum LastShares LastPrice sum LastShares LastPrice sum LastShares from vl now group by orderId gt lt query gt 6 4 CQL Aggregations Oracle CQL supports aggregate functions such as AVG COUNT SUM which are calculated incrementally and MAX and MIN which are not incremental The aggregate functions aggregate events into a Java collection so that you can use the Collection APIs to manipulate the events You can check for conditions on the aggregated results with the HAVING clause In the following example only averages higher than 50 are output SELECT AVG price FROM StockTradeIStreamChannel RANGE 1 HOUR HAVING AVG price gt 50 Oracle CQL Processors 6 9 Configure a Table Source Oracle CQL provides a variety of built in single row functions and aggregate functions based on the Colt open source libraries for high performance scientific and technical computing The functions which are available as part of Colt library will not support Big Decimal data type and NULL input values Also the value computation of the functions are not incremental See the COLT website for details 6 5 Configure a Table Source You can access a relational database table from an Oracle CQL query by creating a table component with an associated data source Oracle Stream Explorer relational database table even
206. for batched events Extends RelationSender to support unbatched events 7 3 1 Implement StreamSender A class that is a source of stream events should send only events that are from the Oracle Stream Explorer standpoint inserted Sending only inserted events models a stream rather than a relation Events sent from a stream source should also have non decreasing time stamps from one event to the event that follows The time stamp of an event that follows another should either be the same as or later than the event that preceded it When you implement St reamSource your code can send events batched or unbatched Your implementation of the St reamSource setEvent Sender method receives a sender instance that you can cast to one of the types described in Table 7 3 Use the sender instance in your code to send events as expected by the downstream stage If your code sends events to a channel that enables batching use one of the batched event senders to batch events by time stamp before sending them For more information see Batch Processing Channels The sender instance provides a sendHeartbeat method to send a heartbeat when the receiving channel is configured to be application time stamped 7 3 2 Implement RelationSender A class that is a source of events as a relation can send insert delete and update events to the downstream stage When you implement the Relat ionSource interface your code can send events batched or unbat
207. form the following tasks All of these tasks happen incrementally without halting the application or causing latency spikes e Pre load a cache with event data before an application is deployed Cached Event Data 8 1 Caching Defined Periodically refresh invalidate and flush the event data in a cache Dynamically update a cache configuration 8 1 1 Supported Caching Implementations Oracle Stream Explorer supports the following caching implementations 8 1 2 Use Cases Oracle Stream Explorer local cache a local in memory single JVM cache This implementation is best for local use it cannot be used in a cluster It might also be useful for development in the early stages because it is relatively simple to set up Oracle Coherence a JCache compliant in memory distributed data grid solution for clustered applications and application servers It coordinates updates to the data using cluster wide concurrency control replicates data modifications across the cluster using the highest performing clustered protocol available and delivers notifications of data modifications to any servers that request them You take advantage of Oracle Coherence features using the standard Java collections API to access and modify data and use the standard JavaBean event model to receive data change notifications Note Before you can use Oracle Stream Explorer with Oracle Coherence you must obtain a valid Oracle Coherence license such as a
208. from an Oracle COL Statement c cccccccecseeseessecsecseessecseessecseenseenees 8 18 8 10 2 Access a Cache from an Adapter ccccccccsessesnsnsnesesseneneescecenesesssnsnseseseseeneeseeeeeenes 8 20 8 10 3 Access a Cache From a Business POJO 0 cccsesssssssecseeseeseceeeesececeneeeesecaeeaeeeeaeeaeeees 8 21 8 10 4 Access a Cache From an Oracle CQL User Defined Function cccccsceesecseeseenees 8 21 8 10 5 Access a Cache With JMX o0 cccccecceseessescesceeesesecsecseeseaecaeeceaesaeseseeceaeaesseeeecaeeaeeeeaeeaeeess 8 23 EclipseLink JPA and Oracle Coherence 9 1 High Level Procedures is irtenen ei eii ea ehgdscvesoehatudesdeuasadscens dsietavedeasvesstesashveh is ee aea ESE aa 9 1 9 2 Melo World Example is deste a E AA E A A e A AaS 9 2 9 2 1 persistence xml Configuration File ccccccsccssesesesesnsneeseeceneescecenesescsesnenessseseeneseseeeees 9 2 9 2 2 HelloWorld Adapter java c cccccccsscscsseseiessssssesesceceesssesnsnsnesesesceesescecenesesssnansnensseseeneneseseees 9 2 9 23 HelloW orld Eventijava sie tases iran a seep vides ae aoa den E ES 9 4 9 2 4 Hellow orld Bean java vx inina a aA ine asin E E E 9 4 9 3 JPA Coherence Example sisia eaa dla taahsts ota Sash e Uh sta a a e a e bap kee 9 6 9 3 1 persistence xml Configuration File ccc cccecsessescsesesesssesessseessesesesesssseesssessenseseeees 9 6 93 2 GlaSS S vs 28s cds ecieee heshie tele ts Paes Min tes A ee ef ile An eee ac 9 6 Web Services
209. fully qualified Java class name of to use for the compound key By default all JavaBean properties in the keyClass are assumed to be keyProperties unless the keyProperties setting is used High Availability Applications 17 35 Configure High Availability Adapters Name Value eventType Specify the type name of the events that the Oracle Stream Explorer high availability input adapter receives from the actual input adapter This is the same event type that you use in the downstream EPN component to which the high availability input adapter is connected For tuple events this property is mandatory For all other Java class based event types this property is optional Configuration File The root element for configuring an Oracle Stream Explorer high availability input adapter is ha inbound adapter The name child element must match the id attribute of the corresponding wlevs adapter element in the assembly file as shown lt ha ha inbound adapter gt lt name gt myHaInputAdapter lt name gt lt heartbeat units millis gt 1000 lt heartbeat gt lt batch size gt 10 lt batch size gt lt ha ha inbound adapter gt Table 17 5 describes the additional child elements Table 17 5 Child Elements Child Element Description heartbeat Specify the length of time that the high availability input adapter can be idle before it generates a heartbeat event to advance time Valid integer values for the units attribute
210. g system ref caching system gt lt wlevs cache gt lt wlevs caching system id caching system provider wlevs advertise false gt 8 3 2 Configuration File The following configuration file settings specify a maximum size and eviction policy for the local caching system The maximum size specifies the number of cache elements in memory after which the eviction policy occurs The example also specifies the maximum amount of time in milliseconds that an entry is cached Default t ime to live value is infinite This example specifies 3600 milliseconds lt caching system gt lt name gt caching system lt name gt lt cache gt lt name gt localcache lt name gt lt max size gt 64 lt max size gt lt eviction policy gt LFU lt eviction policy gt lt time to Live gt 3600 lt time to live gt lt cache gt lt caching system gt 8 8 Developing Applications for Event Processing with Oracle Stream Explorer Configure a Local Caching System and Cache The following configuration file settings add a write behind element as a child element of cache The writ e behind element means Oracle Stream Explorer invokes the cache store from a separate thread after a create or update of a cache entry The child elements of write behind indicate the following e The number of updates that are picked up from the store buffer to write back to the backing store batch size The default value is 100 e The number of attempts that the user thre
211. g with Oracle Stream Explorer Event Inspector Service and you do not specify a local or remote HTTP pub sub server the Event Inspector service uses the local HTTP pub sub server by default Configure for a Local HTTP Publish Subscribe Server For any component configuration file that has a component that you want to test add the event inspector name element as follows lt event inspector gt lt name gt myEvent InspectorConfig lt name gt lt pubsub server name gt myPubSub lt pubsub server name gt lt event inspector gt The pubsub server name value myPubSub is the value of the htt p pubsub element name child element as defined in the local Oracle Stream Explorer server file as the following example shows lt http pubsub gt lt name gt myPubSub lt name gt lt path gt pubsub lt path gt lt pub sub bean gt lt server config gt lt supported transport gt lt types gt lt element gt long polling lt element gt lt types gt lt supported transport gt lt publish without connect allowed gt true lt publish without connect allowed gt lt server config gt lt channels gt lt channels gt lt pub sub bean gt lt http pubsub gt Configure for a Remote HTTP Publish Subscribe Server For any component configuration file that has a component that you want to test add the event inspector name element as follows lt event inspector gt lt name gt myEvent InspectorTraceConfig lt name gt lt pubsub s
212. ge code for Chinese CN is a country code for simplified Chinese whereas TW is the country code for traditional Chinese Therefore zh CN and zh TW are two distinct locales for Chinese Variants are helpful when there is a functional difference in platform vendor handling of specific locales Examples of vendor variants are WIN MAC and POSIX There may be two variants used to further qualify the locale In this case the variants are separated with an underscore for example Tradit ional_Mac as opposed to Modern_MAC Note Language country and variants are all case sensitive A fully qualified locale would look like zh TW WIN identifying traditional Chinese on a Win32 platform Message catalogs to support the above locale involve the following files e xml default catalogs zh xml Chinese localizations zh TW xml Traditional Chinese localizations zh TW WIN xml Traditional Chinese localizations for Win32 code sets Internationalization 12 5 Generate Localization Classes Specific localizations do not need to cover all messages defined in parent localizations 12 2 Generate Localization Classes After you create your message catalog XML files use the weblogic il8ngen utility to create the Logger and TextFormatter classes that localize the text in log messages The weblogic il8ngen utility creates or updates the il8n_user properties properties file that loads the message ID lookup hashtable webl
213. ges that other OSGi bundles need to access These packages are not bundled in and deployed with the application OSGi bundle but are deployed to the Oracle Stream Explorer server application library directory 13 2 Developing Applications for Event Processing with Oracle Stream Explorer Application Libraries 13 3 Application Libraries Application libraries make services and resources available to other applications executing in the same domain You can use application libraries to add functionality such as drivers or foreign stages to your application A foreign stage is a stage that is in another Oracle Stream Explorer application You can add an application library to a project as an embedded JAR file but using an OSGI application library has the following advantages e Simplified application assembly and maintenance activities such as deploying an updated version of the library e Artifact reuse e Reduced server disk space consumption You deploy application libraries to the Oracle Stream Explorer server into the library and library extensions directories 13 3 1 Library Directory By default the Oracle Stream Explorer server library directory is DOMAIN_DIR servername modules for example Oracle Middleware my_oep user_projects domains mydomain myserver modules Oracle Stream Explorer loads the libraries in the library directory after the components in the library extensions directory but before the Oracle Stream Explo
214. gh Availability and Scalability The Oracle Stream Explorer high availability correlating output adapter applies to precise recovery with JMS high availability quality of service option For more information see e Precise Recovery with JMS e Configure the Correlating Output Adapter 17 6 High Availability and Scalability If you need to scale your Oracle Stream Explorer high availability application use the notification groups Spring bean Act iveAct iveGroupBean to increase scalability in JMS applications The Act iveAct iveGroupBean defines a notification group that allows two or more servers to function as a high availability unit while retaining the convenience of a single deployment group that spans all servers primaries and secondaries Figure 17 6 shows three Oracle Stream Explorer application scenarios progressing from the simplest configuration to high availability and then to both high availability and scalability Figure 17 6 High Availability and Scalability Single Server Domain High Availability High Availability and Scalability Deployment i Deployment Group Group Notification Group 1 Host 1 Primary Host 1 Event Event Input gt Output THA Event Output Host 2 Secondary Notification Group 2 Host 3 Primary ven Output Host 4 Secondary ActiveActiveGroupBean _ generated Notification Group Most applications begin
215. gt Alternatively you can specify the bean class in the wlevs function element lt wlevs processor id testProcessor gt lt wlevs listener ref providerCache gt lt wlevs listener ref outputCache gt lt wlevs cache source ref testCache gt lt wlevs function function name mymod exec method execute gt lt bean class com bea wlevs example function MyMod gt lt wlevs function gt lt wlevs processor gt The following Oracle CQL rule assumed to be configured for the tradeProcessor processor shows how to invoke the exist sOrder method of the orderFunction user defined function INSERT INTO InstitutionalOrder SELECT er orderKey AS key er symbol AS symbol er shares as cumulativeShares FROM ExecutionRequest er Range 8 hours WHERE NOT orderFunction existsOrder er orderKey You can also configure the user defined function to access a cache by injecting the function with a cache using the standard Spring mechanism for referencing another bean A cache bean implements the java util Map interface which is what the user defined function uses to access the injected cache First the configuration of the user defined function in the EPN assembly file must be updated with a wlevs property child element as shown in the following example lt wlevs caching system id caching system id gt lt wlevs cache id cache id name alternative cache name gt lt wlevs caching system ref caching system id gt lt
216. guration File The inbound adapter converts incoming JMS messages to a TradeEvent The JNDI factory and service provider are weblogic jndi WLInitialContextFactory and t3 localhost 7101 The incoming client finds the adapter with the JNDI name of JNDIName After the JMS adapter converts the JMS message to an event the adapter sends the events to the JNDI destination of Queuel The optional connect ion jndi name element provides the JNDI name of the JMS connection factory The required dest ination jndi name element provides the JNDI name of the JMS destination The session transacted element when false indicates that the session is not transactional lt jms adapter gt lt name gt jms inbound adapter lt name gt lt event type gt TradeEvent lt event type gt lt jndi provider url gt t3 localhost 7101 lt 4jndi provider url gt lt jndi factory gt weblogic jndi WLInitialContextFactory lt jndi factory gt lt connection jndi name gt JNDIName lt connection jndi name gt lt dest inat ion jndi name gt Queuel lt destination jndi name gt lt session transacted gt false lt session transacted gt lt jms adapter gt 4 10 2 1 Single and Multithreaded Inbound JMS Adapters By default an inbound JMS adapter is single threaded When the inbound JMS adapter is single threaded event order is guaranteed To improve scalability you can configure an inbound JMS adapter to use multiple threads to read messages from the JMS destin
217. h Subscribe adapter converts incoming JavaScript Object Notation JSON messages to event types and back again To customize the way inbound and outbound JSON messages are converted to an event type and back create a custom converter bean 4 10 Developing Applications for Event Processing with Oracle Stream Explorer HTTP Publish Subscribe Adapter Custom Converter Bean 4 9 1 Bayeux Protocol The HTTP Publish Subscribe pub sub server is based on the Bayeux protocol that is proposed by the cometd project The Bayeux protocol defines a contract between the client and the server for communicating with asynchronous messages over HTTP The pub sub server can communicate with any client that understands the Bayeux protocol You can develop your web client with the following frameworks e Dojo JavaScript library that supports the Bayeux protocol Oracle Stream Explorer does not provide this library You can find information about it at http dojotoolkit org e WebLogic Workshop Flex plug in that enables development of a Flex client that uses the Bayeux protocol to communicate with a pub sub server For information about securing an HTTP pub sub server channel see Administering Oracle Stream Explorer 4 9 2 Create a Custom Converter Bean A custom converter bean is a Java class that implements the following interfaces e InboundMessageConverter interface to convert inbound JSON messages to events e OutboundMessageConverter i
218. h as an Oracle CQL processor You can also associate a fault handler with a multithreaded channel which is a channel whose max threads setting is greater than 0 This provides fault handling in the case of exceptions that are thrown to the channel from a stage that is downstream of the channel Note that channels whose max threads setting is 0 are pass through channels that already rethrow exceptions to their upstream stages For additional information specific to fault handlers for channels see Fault Handling A fault handler is a Java class that implements the com bea wlevs ede api FaultHandler interface You connect the class to an EPN stage by registering your fault handler as an OSGi service and associating it with the stage For more information about OSGi see Spring Framework Without a custom fault handler you get the following default fault handling behavior e When an exception occurs in Oracle CQL the CQL engine catches the exception and stops the query processor e Ifan exception occurs in a stage that is downstream to the processor then that stage is dropped as a listener e Exceptions are logged under the CQLServer category and the events that are part of the exception clause are discarded e Upstream stages are not notified of the failure When using custom fault handlers you write you can e Associate a fault handler with an Oracle CQL processor or multithreaded channel so that faults in those stages are thrown
219. hannel gt lt wlevs instance property name eventType value TradeEvent gt lt wlevs instance property name sourceUr1 value file scratch mpawlan oep9 19 oep utils load generator StockData csv gt lt wlevs adapter gt Load Events with a Cache Loader lt wlevs cache id csvcache key properties sequenceNo value type TradeEvent advertise true gt lt wlevs caching system ref cachesys gt lt wlevs cache gt lt bean id csvloader class com oracle cep cacheloader CsvCacheLoader gt lt property name cacheName value csvcache gt lt property name sourceUr1 value file scratch juhe view_storage trade csv gt lt bean gt 8 3 Configure a Local Caching System and Cache You can configure your application to use the Oracle Stream Explorer local caching system and cache The Oracle Stream Explorer local caching system is appropriate when you do not plan to deploy your application to a multiserver domain If you plan to deploy your application to a multiserver domain use an Oracle Coherence cache This chapter describes some of the configuration settings For complete information see Schema Reference for Oracle Stream Explorer 8 3 1 Assembly File The following assembly file settings configure the local caching system and cache The value type setting is the event type into which you want to load the database values lt wlevs cache id localcache value type HelloWorldEvent gt lt wlevs cachin
220. hat Uses an Event Type Builder ccccccecsseeseeteteeeeeeeteseeeenenes 3 17 Adapters Als Create Adapters gosi sek shes is canis Saba E ee aaa to sith ane Sade A E Sete Oe 4 2 4 2 Cluster Distribution Service sic csss a cadeccieecees athe do ale he deck a e ete EA dace heats 4 2 4 34 Password ENcry PUOMs egeton aoei a A ER Sols a E R E 4 3 LA SVAXB SUPPO ne p rE r A E E E E A NE 4 3 AAA EclipseLink MOky ag oeps a A E E E E N S E 4 3 AAD ATT E TEA EOE EO EE E AEAN 4 3 AT SCSV Adapters iit ics Ati Sess a e r e E E E A E E 4 6 46 EDN Adapters i esintisi araoke EE ie AK EEEa ER TEON AE KEE ESAERAREN 4 7 V OPA E VISAS Cs E REA EA AS A A E AEE 4 8 4 6 2 Cre te EDN Adapters ic 2 cts1iit iseia ranap eea A KERKEE EER E AE EER EKER 4 8 47 File Ada pte tes seere ans erna R AA AEREE E A E REA ERE ai 4 9 4 8 HTTP Publish Subscribe Adapter cccccccccccceseseccs cs csseseecscssssseseecscscsssesescscssssseseecsesesnsnseeeseee 4 9 4 9 HTTP Publish Subscribe Adapter Custom Converter Beani cccccccsceccscnenesesescseneeseseees 4 10 4 9 1 Bayeux Protocol crscnasisscsstencistisschutecncseisteeesasechangthdasan ERR Eiere Eo eaae See Sa iaai SAES TRSATA 4 11 4 9 2 Create a Custom Converter Beani ccccccccscccsssssessecssecsecsseesscssseecessesesesceseseseeeeeseeeseseneeaes 4 11 410 IMS Adapters senene t e OE E a EA E ATA A sake i R Steels 4 12 4 1031 S rvice Providers aa aa a a a a Ms es ages ee aa a saae t 4 12 4 10 2 Inbound Adapter
221. have a channel between an adapter and a processor When you use Oracle JDeveloper to connect an adapter to a processor the channel wizard displays for you to create the channel See Getting Started with Event Processing for Oracle Stream Explorer e A channel is optional when you connect any of the following components to an Oracle CQL processor an external relation cache or table source A channel is not needed between a pull source such as a cache or table and a processor because the pull source represents an external relation For an external relation the only valid operation is a join between a stream and a NOW window operator and hence it is considered a pull source The join actually happens outside of the Oracle CQL processor Because it is a pull the Oracle CQL processor does not need Channels 5 1 Channel Configuration 5 2 Channel to be aware of its shape that is no DDL is required and does not need the channel to act as intermediary In general use a channel between components when e Buffering is needed between the emitting component and the receiver e Queueing or concurrency is needed for the receiving component e Ifa custom adapter is used and thread control is necessary Configuration When you add a channel to your Event Processing Network EPN it has a default configuration The default channel has a name an ID is a system time stamped stream channel and has a default heartbeat time out of 100 mil
222. have averaged the price for all stocks To compute the average for specific stocks in the stream the following query uses a partitioned window SELECT AVG price tickerSymbol FROM StockTradeIStreamChannel PARTITION by tickerSymbol ROWS 3 GROUP BY tickerSymbol A partitioned window creates separate relation windows for each partition So in this example with the PARTITION by tickerSymbol clause stocks with the same ticker symbol are grouped by three events and averaged Without the partition and using only the GROUP BY clause the tuple keeps the last three events as expected but the ticker symbols in the tuple do not always match which introduces averaging errors The following is the configuration file entry for this query ISTREAM is a relation to stream operator described in Relation to Stream Operators lt procesor gt lt rules gt lt query id Example gt lt CDATA ISTREAM select tickerSymbol AVG price from StockTradeIStream PARTITION by tickerSymbol ROWS 3 GROUP BY tickerSymbol gt Oracle CQL Processors 6 5 Queries lt query gt lt rules gt lt processor gt 6 3 2 2 Relation to Stream Operators The relation to stream operators are ISTREAM DSTREAM and RSTREAM ISTREAM Operator The ISTREAM operator puts an insert event from the relation into the output stream Events that were deleted or updated in the relation are ignored When the average changes the query sends a delete event to the rel
223. he load generator You register the csvgen adapter using the wlevs adapter element in the EPN assembly file of your application as with all adapters Set the provide attribute to csvgen to specify that the provider is the csvgen adapter rather than your own adapter Additionally you must specify the following child tags e wlevs instance property element with name attribute port and value attribute configured_port where configured_port corresponds to the value of the test port property in the load generator property file See Create the Properties File Testing 1 2 3 14 3 Event Inspector Service e wlevs instance property element with name attribute event TypeName and value attribute event_type_name where event_t ype_name corresponds to the name of the event type that represents an item from the load generated feed e wlevs instance property element with name attribute eventPropertyNames and value attribute ordered_list_of_properties where ordered_list_of_properties lists the names of the properties in the order that the load generator sends them and consequently the csvgen adapter receives them Before showing an example of how to configure the adapter first assume that your application registers an event type called PersonType in the EPN assembly file using the wlevs metada element shown below lt wlevs event type repository gt lt wlevs event type type name PersonType gt lt wlevs properties gt lt wlevs proper
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225. ification Group ccccccceesesteteeececeteseeceenesesesneneneseseeeeeseseeeenes 17 4 175 High Availability Adapters ssns senian e SE e E EER ES 17 5 17 5 1 High Availability Input Adapter ccccscccccsescsseseseeceescecsnenenesesesneneseseeeeeesesssnananenens 17 6 17 5 2 Buffering Output Adapt ti s mesi teinninn aotr ian ienaahi eiae aena eai secara SARNE peirina 17 7 17 5 9 Broadcast Output Adapt r siere pepes aseeksi ienaa ei arare E i eie iea SAR ope TESA 17 7 17 5 4 Correlating Output Adapt t nesip eitri ss ienae h sinsear ithinn ietves ssrt pehi nisana 17 7 17 6 High Availability and Scalability 0 0 0 0 ccc ccescsceceneesesesneteseseeeeceseseecenenesssesnsensseseeeeeseseseeney 17 8 17 7 Choose a Quality of Service Option siiairc insiens rsss ssiie besnikerine ienei res 17 9 AEA NSSE aai o EA ETO E E A Soka ca sd Soe a seas eas Seta 17 9 17 7 2 Simple Failover with Buffering cccccsesseessessseescecesescecenenenesesesnensseeceeeeesesesnananens 17 10 17 7 3 Light Weight Queue Trimming see sssssrstssssrsttssiesstsrteestettesntententerstsntestenntesntentensa 17 10 17 7 4 Precise Recovery with JMS siseissisisseroisrersteresreriero isen nieis dhireas iesto ieis 17 11 17 8 Design Applications for High Availability cccccccceesceseseseecenesesesesnsneseseeceeenesesesnanenens 17 12 17 8 1 Primary High Availability Use Case cccccccsccesesceceseseseenenesesesesneneseececeeesesesnanenene 17 12 17 8 2 High A
226. igure High Availability Quality of Service lt wlevs adapter id myHaSlidingWindowAdapter provider ha buffering gt lt wlevs listener gt lt bean class com bea wlevs example helloworld HelloWorldBean gt lt wlevs listener gt lt wlevs instance property name windowLength value 15000 gt lt wlevs adapter gt 7 Optionally configure the component configuration file to include the Oracle Stream Explorer high availability buffering output adapter as shown lt processor gt lt name gt helloworldProcessor lt name gt lt rules gt lt query id helloworldRule gt lt CDATA select from helloworldInputChannel Now gt lt query gt lt rules gt lt processor gt lt ha ha buffering adapter gt lt name gt myHaSlidingWindowAdapter lt name gt lt window length gt 15000 lt window length gt lt ha ha buffering adapter gt 8 If your application is an Oracle Stream Explorer high availability Type 1 application where the application must generate exactly the same sequence of output events as existing secondaries configure the warm up window length for the buffering output adapter For more information see Choose an Adequate warm up window length Time 9 Deploy your application to the deployment group you created in step 1 Oracle Stream Explorer automatically selects one of the Oracle Stream Explorer servers as the primary 17 9 3 Configure Light Weight Queue Trimming You configure light weight
227. ild element for a particular adapter must match the id attribute of the corresponding wlevs adapter element in the EPN assembly file that declares this adapter as shown lt ha ha correlating adapter gt lt name gt myCorrelatingAdapter lt name gt lt window length gt 15000 lt window length gt lt warm up window length units minutes gt 6 lt warm up window length gt lt ha ha correlating adapter gt Table 17 14 describes the child elements 17 40 Developing Applications for Event Processing with Oracle Stream Explorer Configure High Availability Adapters Table 17 14 Child Elements Child Element Description fail over delay warm up window length window length trimming interval heartbeat batch size Specify the delay timeout in milliseconds that is used to decide how soon after failover correlation should restart Default 0 ms Specify the length of time it takes the application to rebuild state after a previously failed secondary restarts or a new secondary is added as an integer number of units Valid values for attribute units e seconds wait the specified number of seconds e minutes wait the specified number of minutes Default units is seconds For more information see Choose an Adequate warm up window length Time The length of the saved buffer of events in milliseconds The interval at which events should be trimmed from a secondary buffer Units can be events or millis
228. ile lt wlevs caching system id caching system id provider caching provider gt lt wlevs cache id cache id name alternative cache name gt lt wlevs caching system ref caching system id gt lt wlevs cache gt Specify the optional name attribute only when the name of the cache in the caching system is different from its ID The wlevs caching system child element references the already declared caching system that contains the cache You must specify this child element only when there is more than one caching system declared either implicitly or explicitly or when the caching system is in a different application or bundle You can export both the caching system and the cache as an OSGI service with the advertise attribute lt wlevs caching system id caching system id advertise true gt Cached Event Data 8 13 Exchange Data Between a Cache and Another Data Source lt wlevs cache id cache id name alternative cache name advertise true gt lt wlevs caching system ref caching system id gt lt wlevs cache gt If the cache is advertised then a component in the EPN of an application in a separate bundle can reference it The following example shows how a processor in one bundle can use as a cache source the cache with ID cache id located ina separate bundle called cacheprovider lt wlevs processor id myProcessor2 gt lt wlevs cache source ref cacheprovider cache id gt lt wlevs processor gt
229. ile those that do not meet the query terms are deleted from the relation This is important because the integrity of the order in a stream is important Technically a stream is a continuously moving and ordered set of events In a stream every event is inserted into the stream one after the other When you get a subset of 1 4 Developing Applications for Event Processing with Oracle Stream Explorer Application Scalability and High Availability the stream from a CQL query you no longer have the order Before you pass a relation to the next stage in the EPN you can convert the relation back into a stream with the ISt ream operator For more information Customizing Oracle Stream Explorer 1 4 Application Scalability and High Availability A scalable Oracle Stream Explorer application incorporates Oracle Stream Explorer design patterns with implementation and configuration conventions to ensure that the application operation scales as the event load increases You can achieve scalability and high availability by integrating application design patterns server resources and configuration conventions so that your deployed application continues to operate even in the event of software or hardware failures For more information see the following High Availability Applications Scalable Applications 1 5 Application Life Cycle Figure 1 1 shows a state diagram for the Oracle Stream Explorer application life cycle In this diagram the
230. ime period then no events are recorded when the application is deployed and recording happens only after you explicitly start it with Oracle Stream Explorer Visualizer or wlevs Admin You can specify t ime range or time range of fset but not both Debug with Event Record and Playback 15 5 Configure a Component to Record Events Child Element Description time range offset batch size batch time out max size max threads Specifies the time period during which recording takes place Configure the time period with a start child element to specify a start time and a duration child element to specify the length of time to run the recording Express the start time as an XML Schema dat eTime value of the form yyyy mm ddThh mm ss Express the duration in the form hh mm ss For example to have recording start on January 20 2010 at 5 00 am and continue for 3 hours enter the following lt time range offset gt lt start gt 2010 01 20T05 00 00 lt start gt lt duration gt 03 00 00 lt duration gt lt time range offset gt For complete details of the XML Schema dat eTime format see http www w3 org TR xmlschema 2 dateTime lexical representation If you do not specify a time period then no events are recorded when the application is deployed and recording happens only after you explicitly start it with Oracle Stream Explorer Visualizer or wlevs Admin You can specify t ime range
231. implement the com bea wlevs cache spi CachingSystem interface For details about this interface see the Java API Reference for Oracle Stream Explorer Sometimes you might not be able to or want to include the third party caching implementation in the same bundle as the Oracle Stream Explorer application that is using it In this case you must create a separate bundle with a Spring application context that includes the wlevs caching system element with the mandatory advertise attribute lt wlevs caching system id caching system id class third party implementation class advertise true gt Alternately if you want to decouple the implementation bundle from the bundle that references it or you are plugging in a caching implementation that supports multiple caching systems per Java process you can specify a factory as a provider lt wlevs caching system id caching system id provider caching provider gt lt factory id factory id provider name caching provider gt lt class gt the factory class name lt class gt lt factory gt The factory class the factory class name must implement the com bea wlevs cache spi CachingSystemFactory interface This interface has the create method that returns a com bea wlevs cache spi CachingSystem instance You must deploy this bundle with the application bundle so that the application bundle can start using it Add one or more caches for this caching system in the EPN assembly f
232. in channel helloworldOutputChannel to reference the ha broadcast adapter by its id e Addawlevs listener element to the ha broadcast adapter that references the Hel 1oWorldBean class 17 24 Developing Applications for Event Processing with Oracle Stream Explorer Configure High Availability Quality of Service lt wlevs event type repository gt lt wlevs event type type name HelloWorldEvent gt lt wlevs class gt com bea wlevs event example helloworld HelloWorldEvent lt wlevs class gt lt wlevs event type gt lt wlevs event type repository gt lt wlevs adapter id helloworldAdapter class com bea wlevs adapter example helloworld HelloWorldAdapter gt lt wlevs instance property name message value HelloWorld the current time is gt lt wlevs listener ref myHaInputAdapter gt lt wlevs adapter gt lt wlevs adapter id myHaInputAdapter provider ha inbound gt lt wlevs adapter gt lt wlevs channel id helloworldInputChannel event type HelloWorldEvent gt lt wlevs listener ref helloworldProcessor gt lt wlevs source ref myHalInputAdapter gt lt wlevs channel gt lt wlevs processor id helloworldProcessor gt lt wlevs channel id helloworldOutputChannel event type HelloWorldEvent advertise true gt lt wlevs listener ref myHaBroadcastAdapter gt lt wlevs source ref helloworldProcessor gt lt wlevs channel gt lt wlevs adapter id myHaBroadcastAdapter provi
233. in the domain directory then extract the configuration files in the same directory as the application files An assembly file that describes all of the application components and how they connect to each other Place the assembly file in the OSGi bundle JAR file META INF spring directory A MANIFEST MF file that describes the contents of the JAR file This file enables you to make the application resources available to other bundles The following directory structure shows the structure of an OSGi application bundle Figure 13 1 OSGi Application Bundle Structure Treev x Name v Size Type B HelloWorld Ej classes 3 items folder v B classes gt E deploy litem folder B com gt Ei lib 1 item folder 7 W bea gt E META INF 3 items folder v B wlevs gt Ba gt B adapter gt B event gt B example gt BS META INF gt B data gt B deploy b lib v B META INF gt B spring v B wlevs b edn v B mappers gt BS jaxb v B src v B com v B bea v B wlevs gt E adapter gt B event gt B example X src litem folder HelloWorld jpr 11 9 KB JBuilder project 13 2 Application Dependencies Applications depend on imported packages and libraries which can be shared with other applications executing in the same domain You specify OSGi bundle dependencies in the MANIFEST MF as follows Use the Import Package attribute to list imported packages and libraries Use the Export Package attribute to list packa
234. in your Oracle Stream Explorer installation The load generator reads an ASCII file that contains sample data You must use the CSV Inbound adapter because it is coded to decipher the data packets generated by the load generator See Load Generator and the csvgen Adapter Note With the java sql TimeStamp type the CSV adapter reads and writes data in the format yyyy mm dd T hh mmiss fffffffff For example 2012 12 12T12 12 12 120 The best way to create CSV adapters is through the Oracle JDeveloper components window The following assembly and configuration files generated by Oracle JDeveloper show the CSV inbound and outbound adapter configurations Assembly File The inbound CSV adapter translates data read from the StockData csv file into an event with the TradeEvent event type The wlevs listener element specifies the component that listens to the inbound CSV adapter for TradeEvent activity In this example the listener is AdapterOutputChannel The AdapterOutputChannel component listens for and 4 6 Developing Applications for Event Processing with Oracle Stream Explorer EDN Adapters receives trade events from StockTradeCSVInboundAdapter to send to the next stage lt wlevs adapter id StockTradeCSVInboundAdapter provider csv inbound gt lt wlevs listener ref AdapterOutputChannel gt lt wlevs instance property name eventType value TradeEvent gt lt wlevs instance property name sourceUrl value fi
235. ine your own group pattern to specify a different notification group naming pattern 1 Configure the assembly file to add a groupPattern attribute to your ActiveActiveGroupBean element as shown lt bean id clusterAdapter class com oracle cep cluster hagroups ActiveAct iveGroupBean gt lt property name groupPattern value MyNotificationGroupPattern gt lt bean gt 2 Specify a value for the groupPattern attribute that matches the cluster group naming convention you want to use for notification groups 18 4 Custom Channel Event Partitioner Most channels use the default event partitioning described in Developing Applications for Event Processing with Oracle Stream Explorerwhere if no partitioner is specified and if the partitionByEventProperty element is not present the channel sends events to all listeners The partitionByEventProperty element provides a level of customization by partitioning on the specified event with a default partitioning algorithm This section explains how you can further customize how events are dispatched to the channel listeners by programmatically configuring a custom partitioner that provides finer control over the default partitioning algorithm For example you can create an event partitioner that is based on a property range 18 4 1 EventPartitioner Interface Use the com bea wlevs channel EventPartitioner interface to partition events across a channel to customize how events are dispatched to
236. ing event partitioning and a class for managing the number of events in channels See Channels and Scalable Applications 1 8 Developing Applications for Event Processing with Oracle Stream Explorer API Overview Event Repositories To manage events and event types Oracle Stream Explorer uses an event store repository and an event type repository The event store repository persists the event and the event type repository persists the event type Packages e com bea wlevs eventstore package provides interfaces and classes to manage the event store repository See Using Visualizer for Oracle Stream Explorer e com bea wlevs ede api package provides the Event TypeRepository interface to manage the event type repository See Events and Event Types Event Driven Environment The com bea wlevs ede api package provides interfaces for creating and customizing Oracle Stream Explorer application code that responds to events The package provides interfaces for creating event beans and adapters and making them event sinks and event sources Other interfaces in this package enable you to manage all aspects of how events flow through the EPN such as event creation event flow through channels event metadata and properties the event type repository external data sources EPN stages fault handling event bean life cycle and so on For sample Java code that uses some of these APIs see Events and Event Typesand Event Beans See also Resou
237. ing sections Install an Application or Start the Server with the Application Deployed Oracle Stream Explorer performs the following actions 1 Oracle Stream Explorer installs the application as an OSGI bundle OSGI resolves the imports and exports and publishes the service 2 Oracle Stream Explorer creates beans for both standard Spring beans and those that correspond to the Oracle Stream Explorer tags in the EPN assembly file For each bean Oracle Stream Explorer e Sets the properties on the Spring beans The lt wlevs instance property gt values are set on adapters and event beans e Injects appropriate dependencies into services specified by Service or ServiceReference annotations e Injects appropriate dependencies into static configuration properties e Calls the InitializingBean afterPropertiesSet method e Calls configuration callbacks P repare Act ivate on Spring beans as well as factory created stages For more information see Resource Access Configuration 3 Application state is now INITIALIZING 4 Oracle Stream Explorer registers the MBeans 5 Oracle Stream Explorer calls the ActivatableBean afterConfigurationActive method on all ActivatableBeans 6 Oracle Stream Explorer calls the ResumableBean beforeResume method on all ResumableBeans 7 For each bean that implements RunnableBean Oracle Stream Explorer starts it running in a thread 8 Application state is now RUNNING
238. ink interface has three methods one of which it inherits from the St reamSink interface onInsertEvent onDeleteEvent and onUpdateEvent At runtime the Oracle Stream Explorer server calls the appropriate method depending on which type of event is received from the upstream channel connected to your class public class TradeListener implements RelationSink public void onInsertEvent Object event throws EventRejectedException if event instanceof TradeEvent String symbolProp TradeEvent event getSymbol Integer volumeProp TradeEvent event getVolume Do something with the inserted event Override public void onDeleteEvent Object event throws EventRejectedException if event instanceof TradeEvent Do something with the deleted event Override public void onUpdateEvent Object event throws EventRejectedException if event instanceof TradeEvent Do something with the updated event Event Beans 7 5 Event Source Interfaces Implement the Bat chRelationSink interface if your class receives batched events as a relation It has an onEvents method designed to receive all three types of events from the batch in java util Collection instances onEvents insertEvents deleteEvents updateEvents In addition the BatchRelationSink interface extends the Relat ionSink interface to support receiving unbatched events At runtime the Oracle Stream Explorer server calls
239. ion Accessibility For information about Oracle s commitment to accessibility visit the Oracle Accessibility Program website at http www oracle com pls topic lookup ctx acc amp id docacc Access to Oracle Support Oracle customers that have purchased support have access to electronic support through My Oracle Support For information visit http www oracle com pls topic lookup ctx acc amp id info or visit http www oracle com pls topic lookup ctx acc amp id trs if you are hearing impaired Related Documents For more information see the following e Getting Started with Event Processing for Oracle Stream Explorer e Administering Oracle Stream Explorer e Using Visualizer for Oracle Stream Explorer e Oracle CQL Language Reference for Oracle Stream Explorer e Schema Reference for Oracle Stream Explorer Developing Applications with Oracle CQL Data Cartridges Customizing Oracle Stream Explorer e Java API Reference for Oracle Stream Explorer e Oracle Database SQL Language Reference at http docs oracle com cd 16655_01 server 121 e17209 toc htm xi xii e SQL99 Specifications ISO IEC 9075 1 1999 ISO IEC 9075 2 1999 ISO IEC 9075 3 1999 and ISO TEC 9075 4 1999 e Oracle Stream Explorer Forum http forums oracle com forums forum jspa forumID 820 Conventions The following text conventions are used in this document Convention Meaning boldface italic monospace Boldface ty
240. ion about adapter settings see Schema Reference for Oracle Stream Explorer See also the Oracle Middleware my_oep oep wlevs_application_config xsd directory in your Oracle Stream Explorer installation for adapter schema information 4 2 Cluster Distribution Service The cluster distribution feature provides a mechanism for various Oracle Stream Explorer adapter types to distribute incoming events to all of the servers in a cluster An individual adapter or event bean instance can be configured to distribute events and in this case all input events processed by that adapter are sent distributed to all servers in the cluster The distribution adapter ensures that all input events are sent distributed to all servers in the cluster To convert an input adapter to a distribution adapter add the distributeInput element and set it to t rue as follows The distributionThreadsCount property is optional and defaults to 1 lt wlevs adapter id myLoadgenAdapter provider loadgen gt lt wlevs instance property name distributeToClusterGroup value true gt lt wlevs instance property name distributionThreadsCount value 1 gt lt wlevs adapter gt Oracle Stream Explorer supports the Cluster Distribution service for the loadgen CSV inbound and JMS inbound queue adapters Oracle Stream Explorer does not support the Cluster Distribution service for the CSV outbound JMS inbound topic JMS outbound and HTTP publish subscribe adapters
241. ionSink interface MyEventListener listener new MyEventListener Connect channel chl and processor pl commandSession link StreamSource chl StreamSink pl Connect channel pl and processor ch2 commandSession link StreamSource pl StreamSink ch2 Connect channel ch2 and processor listener commandSession link StreamSource ch2 StreamSink listener Create the query in processor p commandSession createQuery pl ql select from cl Create event el and assign two properties a and 1 Object el new MyEvent a 1 Send insert event el to channel ch1 chl sendInsertEvent el Test whether event el equals the event retrieved by the listener assertEquals el listener getEvent End the session commandSession end Testing 1 2 3 14 17 EPN Command Interface 14 18 Developing Applications for Event Processing with Oracle Stream Explorer 15 Debug with Event Record and Playback You can use the event record and playback feature to debug a running Oracle Stream Explorer application While the application runs you record the events that flow out of an EPN component into a persistent store You play the events back at a later stage in the application such as in an event bean In the event bean you query the events and make fixes to your application based on your findings The sample code in this chapter is from the event record and playback example in Oracle Middleware m
242. ithout views You define application parameters attributes by grouping attribute definitions ADs into object class definitions OCDs You create one OCD for each application component that you want to parameterize An OCD contains one or more ADs to specify the component properties to parameterize and the prompt text Place the OCDs in an XML document metatype file in the OSGI INF metatyp directory within the Oracle Stream Explorer application The metatype file uses and complies with the schema defined by the specification at http www osgi org xmlns metatype vl 1 0 metatype xsd See Example metatype File for an example configuration Oracle Stream Explorer parameterized applications conform to the OSGi MetaType specification at http www osgi org See the Apache implementation at http felix apache org documentation subprojects apache felix metatype service html Parameterized Applications 11 1 Object Class Definitions 11 2 Object Class Definitions Every OCD requires the name id and description parameters The following example is an OCD with no ADs This OCD defines application metadata but because there are no ADs the description displays but the user is not prompted for input This type of OCD documents the application lt OCD name HelloWorld Sample id com oracle cep sample helloworld description The helloworld OEP application is a sample application for Oracle Event Processing gt lt
243. itional packages to include on the manifest Import Package attribute Note that any specified import modifiers will not be applied A space delimited list of one or more packages or regular expressions that select the packages to exclude from the manifest Export Package attribute By default all bundle packages will be exported The export modifiers will be applied to the packages matching regular expression Packages to include on the manifest DynamicImport Package attribute This optional flag specifies that the content of the source JAR should be exploded into the target JAR file By default the source JAR is nested within the target JAR file and the generated bundle manifest will contain an appropriate Bundle Classpath attribute An optional flag to enable verbose output 13 7 6 2 Assemble an OSGi Bundle 1 Execute the bundler sh script to create an OSGi bundle See Command Location Syntax and Arguments 13 12 Developing Applications for Event Processing with Oracle Stream Explorer Assemble an OSGi Bundle with bundle sh The following bundle sh command shows how to use the bundler sh to create an OSGi bundle for an Oracle JDBC driver bundler sh source C drivers com oracle ojdbc14_11 2 0 jar name oraclel2c version 12 1 3 0 factory oracle jdbc xa client OracleXADataSource oracle jdbc OracleDriver service javax sql XADataSource java sql Driver targetdir C stage The source o
244. iving as streams As described in the following table the interfaces are hierarchically related Interface Description com bea wlevs ede api StreamSink Implement to receive events sequentially ina stream com bea wlevs ede api RelationSi Implement to receive events sequentially ina nk relation Extends St reamSink to receive events in a stream com bea wlevs ede api BatchStrea Implement to receive batched events ina mSink stream Events might arrive batched by time stamp when the upstream channel allows batching Extends St reamSink to support receiving events unbatched com bea wlevs ede api BatchRelat Implement to receive batched events as a ionSink relation Events might arrive batched by time stamp when the upstream channel allows batching Extends Relat ionSink to support receiving events unbatched as streams or relations EventRejectedException Behavior in onInsertEvent Implementations You need to explicitly throw EventRe jectedException in onInsertEvent implementations for exceptions you do not want to get dropped You can raise an EventProcessingException and it is propagated all the way to the source of the error through a CQL processor An EventRejectedException can chain exceptions from its downstream listeners in case there is more than one exception The CQL processor converts the Event Re jectedException to a soft exception See Fault Handling for more information 7 2 1 Implement
245. javax persistence Entity import javax persistence Id Entity public class SaleEvent implements java io Serializable Id private String itemID private double salePrice public SaleEvent public SaleEvent String itemID double salePrice this itemID itemID this salePrice salePrice public String getItemID return itemID public void setItemID String itemID this itemID itemID public double getSalePrice return salePrice public void setSalePrice double salePrice this salePrice salePrice public String toString return SaleEvent itemID salePrice 9 3 2 5 SaleEventsGenerator java package com oracle cep sample import java util Map import java util Random import com bea wlevs ede api RunnableBean import com bea wlevs ede api StreamSender import com bea wlevs ede api StreamSource import com bea wlevs ede api InitializingBean 9 10 Developing Applications for Event Processing with Oracle Stream Explorer JPA Coherence Example public class SaleEventsGeneraton implements RunnableBean StreamSource InitializingBean private static final int SLEEP_MILLIS 1000 private static final String s_itemIDs kodaksport ipodtouch 8GB ipad2 kindle garminl690 rebel logitech1080 tomtom ipad2 cuisinartl0s keurig b70 lasko1320 private static final double s_prices 60 0 200 0 450 0 99 120 400 70 100
246. jndi name gt RMIOut boundJNDIName lt jndi name gt lt jndi provider url gt t3 localhost 7001 lt jndi provider url gt lt jndi factory gt weblogic jndi WLInitialContextFactory lt jndi factory gt lt rmi adapter gt Adapters 4 23 RMI Adapters 4 24 Developing Applications for Event Processing with Oracle Stream Explorer 5 Channels A channel represents the logical conduit through which events flow between other types of components stages For example between adapters and Oracle CQL processors or between Oracle CQL processors and event beans This chapter includes the following sections e When to Use a Channel e Channel Configuration e Control Which Queries Output to a Downstream Channel e Batch Processing Channels e Fault Handling e EventPartitioner Channels e Distributed Flows 5 1 When to Use a Channel Channels provide buffering queuing and concurrency capabilities that enable you to tune the performance of your application later in the design life cycle By default the channel max threads attribute is set to 0 which means the channel is in pass through mode and incurs no performance penalty When constructing your EPN consider the following rules e A channel is mandatory when you connect an Oracle CQL processor to a downstream stage e A channel is mandatory when you connect a stream or relation to an Oracle CQL processor Note that based on the previous two points it is mandatory to
247. jndi provider url gt t3 ppurich pc 7001 lt jndi provider url gt lt destination jndi name gt Topicl lt destination jndi name gt lt session transacted gt true lt session transacted gt lt jms adapter gt lt jms adapter gt lt name gt JMS InboundAdapter2 lt name gt lt event type gt StockTick lt event type gt lt jndi provider url gt t3 ppurich pc 7001 lt jndi provider url gt lt destination jndi name gt Topic2 lt destination jndi name gt lt session transacted gt true lt session transacted gt lt jms adapter gt lt jms adapter gt lt name gt JMSOutboundAdapter lt name gt lt event type gt StockTick lt event type gt lt jndi provider url gt t3 ppurich pce 7001 lt jndi provider url gt lt destination jndi name gt Topic2 lt destination jndi name gt lt session transacted gt true lt session transacted gt lt jms adapter gt lt wlevs config gt 18 3 Notification Group Naming Conventions By default the Act iveAct iveGroupBean class creates notification groups with the following name where X is a string ActiveActiveGroupBean_X Scalable Applications 18 11 Custom Channel Event Partitioner At runtime Act iveAct iveGroupBean scans the existing groups defined on the Oracle Event Processing server and applies the following default pattern match When ActiveActiveGroupBean finds a match it creates a notification group with that name ActiveActiveGroupBean_ w Optionally you can def
248. k JPA and Oracle Coherence 9 5 JPA Coherence Example 9 3 JPA Coherence Example The JPA Coherence example demonstrates the usage of the EclipseLink JPA implementation for the Coherence CacheLoader or CacheStore interfaces 9 3 1 persistence xml Configuration File The EclipseLink properties specify the settings for database read and write operations and logging The managed persistable classes that represents objects in the database are com oracle cep sample PriceTarget and com oracle cep sample SaleEvent This persistence xml file has entries for JPA logging that are commented out and set to false You can uncomment these settings and set them to t rue to debug or otherwise monitor the application behavior For information on property settings see http eclipse org eclipselink documentation 2 4 jpa extensions toc htm lt xml version 1 0 encoding UTF 8 gt lt persistence xmlns xsi http www w3 org 2001 XMLSchema instance xsi schemaLocation http java sun com xml ns persistence http java sun com xml ns persistence persistence_2_0 xsd version 2 0 xmlns http java sun com xml ns persistence gt lt persistence unit name derby transaction type RESOURCE_LOCAL gt lt class gt com oracle cep sample PriceTarget lt class gt lt class gt com oracle cep sample SaleEvent lt class gt lt properties gt lt property name eclipselink jdbc read connections min value 1 gt lt property name eclipselink
249. lar version that changes You can create a single log message catalog for all logging requirements or create smaller catalogs based on a subsystem or on Java packages Oracle recommends using multiple subsystem catalogs so you can focus on specific portions of the log during viewing For simple text catalogs Oracle recommends that you create a single catalog for each utility to be internationalized 12 1 1 Hierarchy 12 1 2 Naming All messages must be defined in the default top level catalog Catalogs that provide different localizations of the base catalogs are defined in msgcat subdirectories named for the locale for example msgcat de for Germany You might have a top level catalog named mycat xml and a German translation called de mycat xml Typically the top level catalog is English However English is not required for any catalogs Locale designations for example de also have a hierarchy as defined in the java util Locale documentation A locale can include a language country and variant Language is the most common locale designation Language can be extended with a country code For example en US indicates American English The name of the associated catalog is en US mycat xml Variants are specific to a vendor or browser and are used to introduce minor differences such as collation sequences between two or more locales defined by either language or country Because the name of a message catalog file wi
250. latingAdapter provider ha correlating gt lt wlevs listener ref JMSOutboundAdapter gt lt wlevs instance property name failOverDelay value 2000 gt lt wlevs instance property name correlatedSource ref clusterCorrelatingOutstream gt lt wlevs adapter gt If your application is an Oracle Stream Explorer high availability Type 1 application where the application must generate exactly the same sequence of output events as existing secondaries configure the warm up window length for the correlating output adapter Configure the component configuration file to enable session transacted for both inbound JMS adapters and the outbound JMS adapter as the following example shows lt jms adapter gt lt name gt JMS InboundAdapter lt name gt lt jndi provider url gt t3 localhost 7001 lt jndi provider url gt lt destination jndi name gt Topicl lt destination jndi name gt lt user gt weblogic lt user gt lt password gt weblogic lt password gt lt work manager gt Jett yWorkManager lt work manager gt lt concurrent consumers gt 1 lt concurrent consumers gt lt session transacted gt true lt session transacted gt lt jms adapter gt lt jms adapter gt lt name gt JMS InboundAdapter2 lt name gt lt jndi provider url gt t3 localhost 7001 lt jndi provider url gt lt destination jndi name gt Topic2 lt destination jndi name gt lt user gt weblogic lt user gt lt password gt weblogic lt password gt l
251. le scratch mpawlan oep9 19 oep utils load generator StockData csv gt lt wlevs adapter gt The outbound adapter assembly file configuration is similar to the inbound adapter but includes an append attribute When set to t rue Oracle Stream Explorer appends data to an existing output file When set to false Oracle Stream Explorer creates a new file or overwrites an existing file of the same name lt wlevs adapter id StockTradeCSVOutboundAdapter provider csv outbound gt lt wlevs instance property name eventType value TradeEvent gt lt wlevs instance property name outputFile value scratch mpawlan oep9 19 oep utils load generator StockData csv gt lt wlevs instance property name append value false gt lt wlevs adapter gt You can provide an absolute or relative path for the out put File value For the relative path you can specify filename csv result csv or upload result csv When you specify a relative path make sure that the abstract path includes the parent directory For example in UNIX specify a file in the current directory as result csv instead of simply result csv Configuration File The adapter elements in the configuration file show the adapter name attribute and its value The adapter name must match the adapter id attribute in the assembly file lt csv adapter gt lt name gt StockTradeCSVInboundAdapter lt name gt lt event interval units nanoseconds gt 5 lt event interval gt
252. le Stream Explorer Visualizer or you can edit a component configuration file in your application to specify injection settings that are in place when the application is deployed or redeployed Configure event injection in Oracle Stream Explorer Visualizer with settings that can be discarded when the application is redeployed See Using Visualizer for Oracle Stream Explorer For event injection configuration settings that are in place when the application is deployed or redeployed configure injection by editing component configuration settings for the stage to which you want to inject For example the component configuration excerpt shown in the example illustrates how you might configure a processor for event injection The inject parameters element s act ive child element specifies that injection is on while the channel name element specifies the HTTP pub sub channel from which injected elements should be sent lt processor gt lt name gt FindCrossRates lt name gt lt inject parameters gt lt active gt true lt active gt lt channel name gt NonClusteredServer fx FindCrossRates output lt channel name gt lt inject parameters gt lt rules gt lt Query rules omitted gt lt rules gt lt processor gt For reference information about the elements see Schema Reference for Oracle Stream Explorer 14 2 5 Trace Events After you configure the Event Inspector service HTTP pub sub server you can use Event Inspector
253. le Stream Explorer provides different ways to test your application depending on what and how you want to test This chapter includes the following sections e Load Generator and the csvgen Adapter e Event Inspector Service e EPN Shell e EPN Command Interface 14 1 Load Generator and the csvgen Adapter The load generator utility simulates a data feed so that you can test your application without connecting to a real world data feed To test your application with the load generator you must use the csvgen adapter in your application because the csvgen adapter is specifically coded to decipher the data packets generated by the load generator Once you have tested your application with the csvgen adapter you can replaced it with the appropriate input adapter for your application as described in Adapters The load generator reads an ASCII file that contains the sample data feed information and sends each line of data in order to a port The csvgen adapter listens for data at the same port A load generator properties file indicates the name of the data file the port where the server listens the server host and the packet type You can also set the data rate and how long it takes for the load generator to ramp up to a specified final rate The following steps present an overview of how to configure and run the load generator utility Detailed information for each step follows 1 Create a properties file that contains the configuration
254. le or by editing the component configuration file You can edit anything you want in the files but you have to be careful to keep the assembly file ID value consistent with the configuration file name value If you change the ID value in the assembly file you have to change the name value in the configuration file to match and vice versa You can change any other information in one file only Oracle JDeveloper uses the ID and name value pairing to keep the information in the application assembly and component configuration files synchronized The following components have a configuration file that defaults to processor xml Oracle CQL patterns must be placed in the processor xm1 file but all other components in this list can use a configuration file by another name e All adapters e Channels e Oracle COL Patterns e Local Cache System e Cache e RMIJOutbound extension The Coherence Cache System has a default coherence cache file You can change the name of this file Component configuration files are deployed as part of the Oracle Stream Explorer application bundle You can later update this configuration at runtime using Oracle Stream Explorer Visualizer the wlevs Admin utility or by manipulating the appropriate JMX MBeans 2 2 Assembly File Structure The spring wlevs v12_1_3_0 xsd schema file describes the EPN assembly file structure This schema file is installed in the Oracle Middleware oep xsd directory See Schema
255. lement and the wlevs event type child element Create a Tuple Event Type in the Assembly File The following XML stanzas create a the CrossRateEvent tuple event type with the properties price fromRate and toRate lt wlevs event type repository gt lt wlevs event type type name CrossRateEvent gt lt wlevs properties gt lt wlevs property name price type double gt lt wlevs property name fromRate type char gt lt wlevs property name toRate type char gt lt wlevs properties gt lt wlevs event type gt lt wlevs event type repository gt See Schema Reference for Oracle Stream Explorer 3 8 2 Use a Tuple Event Type in Java Code Before you can use a tuple event type in Java code you must create an event type repository You use the event type repository to get the property names and values so you can work on them in your code To create an event type repository include the com bea wlevs ede api EventTypeRepository class The following code is part of an event sink class The code creates an event type repository with a call to the setEvent TypeRespository method The Oracle Stream Explorer server then calls the onInsertEvent method with an event parameter The onInsertEvent method gets information about the event from the event type repository For more information about creating an Event TypeRepository object see Access the Event Type Repository Service Create an event typ
256. lement specifies the work manager to use to asynchronously invoke listeners This value is ignored if synchronous invocations are enabled If a work manager is specified for the cache this value overrides that setting for invoking listeners only The value of the work manager name element corresponds to the name element of the work manager setting in the Oracle Stream Explorer config xml server configuration file lt caching system gt lt name gt caching system id lt name gt lt cache gt lt name gt cache id lt name gt lt max size gt 100000 lt max size gt lt eviction policy gt LRU lt eviction policy lt time to live gt 3600 lt time to live gt lt write behind gt lt buffer size gt 200 lt buffer size gt lt buffer write attempts gt 2 lt buffer write attempts gt lt buffer write timeout gt 200 lt buffer write timeout gt lt write behind gt lt listeners asynchronous true gt lt work manager name gt cachingWM lt work manager name gt Cached Event Data 8 9 Configure a Cache as an Event Listener lt listeners gt lt cache gt lt caching system gt 8 4 Configure a Cache as an Event Listener You can configure a cache to receive events as they pass through the network For example to specify that a cache listens to a channel configure the channel with a wlevs listener element that has a reference to the cache In the following example as the channel sends new events to the cache the events are in
257. lications for Event Processing with Oracle Stream Explorer Message Catalogs Locale Specific Catalog This example shows a French translation of a message that is in the msgcat fr MyUtilLabels xml file lt xml version 1 0 gt lt DOCTYPE message_catalog PUBLIC weblogic locale message catalog dtd http www bea com servers wls90 dtd 110n_msgcat dtd gt lt locale_message_catalog 110n_package programs utils subsystem MYUTIL version 1 0 gt lt message gt lt messageid FileMenuTitle gt lt messagebody gt Fichier lt messagebody gt lt message gt lt locale_message_catalog gt When you enter text in the messagebody messagedetail cause and action elements use a tool that generates valid Unicode Transformation Format 8 UTF 8 characters and have appropriate keyboard mappings installed UTF 8 is an efficient encoding of Unicode character strings that optimizes the encoding ASCII characters Message catalogs always use UTF 8 encoding 12 1 5 Message Catalog Localization Catalog subdirectories are named after lowercase two letter ISO 639 language codes for example ja for Japanese and fr for French You can find supported language codes in the java util Locale Javadoc You can achieve variations to language codes with uppercase two letter ISO 3166 country codes and variants each of which are subordinate to the language code The generic syntax is lang country variant For example zh is the langua
258. lications to a group of two or more Oracle Stream Explorer servers running in a multiserver domain Oracle Stream Explorer chooses one server in the group to be the active primary server The other servers become active secondary servers The primary and secondary servers are configured to receive the same input events and process them in parallel but only the primary server outputs events to the Oracle Stream Explorer application client Depending on the quality of service you choose the secondary servers buffer their output events using in memory queues and the primary server keeps the secondary servers up to date with which events the primary has already output Figure 17 1 shows a typical configuration with one active server and two primary servers Figure 17 1 Oracle Stream Explorer High Availability Primary and Secondary Servers Input Streams Multi Server Domain Deployment Group and Notification Group Server 1 Server 2 Server 3 ey Secondary Secondary Queue Queue Output Streams Streams 17 3 Life Cycle and Failover Figure 17 2 shows a state diagram for the Oracle Stream Explorer high availability life cycle In this diagram the state names SECONDARY BECOMING_PRIMARY and PRIMARY correspond to the Oracle Stream Explorer high availability adapter RuntimeMBean method get State return values These states are specific to Oracle Stream Explorer See High Availability Input Adapter for more information a
259. license for Coherence Enterprise Edition Coherence Grid Edition or Oracle WebLogic Application Grid For more information on Oracle Coherence see http docs oracle com middleware 1213 coherence index html Third party caches you can create a plug in to allow Oracle Stream Explorer to work with other third party cache implementations Caching technology is a great fit for streaming data use cases where high throughput can be particularly important Getting data from a cache is usually much faster than getting the same data from a relational database The following scenarios describe common use cases for caching in Oracle Stream Explorer applications Publish events to a cache A financial application publishes events to a cache while the financial market is open and then processes data in the cache after the market closes Publishing events to a cache makes them available to the application or available to other Oracle Stream Explorer applications running in the server Publishing events to a cache also allows for asynchronous writes to a secondary storage by the cache implementation Consume data from a cache Oracle Stream Explorer applications sometimes need to access non streaming data By caching this data you can increase the performance of the application The standard components of an Oracle Stream Explorer application that are allowed 8 2 Developing Applications for Event Processing with Oracle Stream Explorer Co
260. liseconds or 100 000 000 nanoseconds The default configuration is adequate for most applications You can modify the configuration by editing the application assembly file or by editing the component configuration file When a channel is time stamped by the system Oracle Stream Explorer assigns a new time from the CPU clock when a new event arrives and when the configurable heartbeat time out expires When a channel is time stamped by an application the time stamp of an event is determined by the wlevs expression element A common example of an expression is a reference to a property on the event If no expression is specified then the time stamp can be propagated from a prior event For example when a channel that is time stamped by the system from one Oracle CQL processor feeds events into a channel that is time stamped by an application of another downstream Oracle CQL processor In addition an application can use the St reamSender sendHeartbeat method to send an event of type heart beat downstream to St reamSink listeners in the EPN Note When a channel is both application time stamped and map based uses a hash map event type Oracle Stream Explorer adds a time stamp A delete or update operation without a key does not work on a channel with this configuration because application time stamped events hold an always changing timestamp property This chapter describes some of the assembly and configuration file channel
261. lorer application through programming 14 4 1 Session Variables You can set session variables to indicate the time stamp format to use for output events The time stamping can be FORMATTED PLAIN or OFF 14 4 2 Methods void beginSession Begins a new session for invoking commands Only a single session can be active at one time The following list shows the EpnCommand methods and parameters Refer the EpnCommand Javadoc for more information endSession Ends the current session Only a single session can be active at one time void getEventChannels Returns all channels created in the current session EventChannel getEventChannel String channelName Returns the named event channel EventChannel getEventChannel String channelName Retrieves the named event channel Create different types of channels based on the parameters e EventChannel createChannel String channelName Class lt gt clazz Create a new system time stamped channel with a Java class event type e EventChannel createChannel boolean relation String applicationTimestampProp boolean totalOrder List lt String gt keys String channelName Class lt gt class Create a new channel with a Java class event type e EventChannel createChannel boolean relation String applicationTimestampProp boolean totalOrder List lt String gt keys String channelName Class lt gt class EventBuilder Factory factory Crea
262. m bea wlevs monitor package provides interfaces for monitoring the throughput and latency of application endpoints in the event server 1 10 Developing Applications for Event Processing with Oracle Stream Explorer API Overview com bea wlevs monitor management package provides interfaces for receiving monitoring metrics for an application stage and for monitoring latency between endpoints in the EPN com bea wlevs deployment mbean package provides interfaces to manage application deployment com bea wlevs eventinspector management package provides interfaces and classes for controlling the behavior of event tracing and event injection See Testing 1 2 3 com oracle cep cluster ha adapter management package provides interfaces and classes for managing JMX communications in a high availability environment High Availability Oracle Stream Explorer provides application design patterns and high availability adapters to enable you to increase the backup and failover processing capabilities of your applications See High Availability Applications Packages com oracle cep cluster ha adapter package provides interfaces and classes for queue trimming com oracle cep cluster ha adapter inbound package provides classes for creating a high availability broadcast inbound adapter This adapter is for applications that use system time and need to be highly available com oracle cep cluster ha adapter management package provides inter
263. m number of threads you expect to have active in any CQL processor instance In some cases for example at high data rates or with expensive processing downstream from the CQL processor it may be helpful to set the part ition order capacity value even higher than the available number of threads However you should only do this if performance testing confirms that it s helpful for a given application and load The partition order capacity value is set from one of four places two of which you can fall back on when you do not explicitly set it yourself For information about the settings see Schema Reference for Oracle Stream Explorer These are in order of precedence Oracle CQL Processors 6 13 Configure an Oracle CQL Processor for Parallel Query Execution 1 The partition order capacity element set on a channel configuration If you specify this on the input channel for a processor it takes effect for any PARTITION_ORDERED queries in that processor 2 The partition order capacity property in server configuration This value will be used for all PARTITION_ORDERED queries running on the server unless the value is set on a channel 3 The max threads value set on a channel configuration If you specify this on the input channel for a processor it takes effect for any PARTITION_ORDERED queries in that processor 4 A system default value currently set to 4 is used if you don t specify either a par
264. mat new Date HelloWorldEvent event new HelloWorldEvent event setMessage message eventSender sendInsertEvent event public void setEventSender StreamSender sender eventSender sender public synchronized void suspend suspended true private synchronized boolean isSuspended return suspended EclipseLink JPA and Oracle Coherence 9 3 HelloWorld Example 9 2 3 HelloWorldEvent java The HelloWorldEvent java class creates an event from a message The HelloWorld Adapter generateHelloMessage method calls the HelloWorldEvent setMessage method to create an event from a message The HelloWorldBean class stores the message and its generated id to and retrieves them from the data store package com bea wlevs event example helloworld import javax persistence Entity import javax persistence GeneratedValue import javax persistence GenerationType import javax persistence Id Entity public class HelloWorldEvent Id GeneratedValue strategy GenerationType IDENTITY private long id private String message public String getMessage return message public void setMessage String message this message message 9 2 4 HelloWorldBean java The Hel loWorldBean java class is an event sink and source that retrieves events from Hel loWorldEvent and performs read and write operations on the database with JPA The Oracle Stream Explorer framework
265. mber of duplicates can be output On the other hand a larger buffer reduces the chances of missed messages When an Oracle Stream Explorer server rejoins the multiserver domain if your application is an Oracle Stream Explorer high availability Type 1 application the application must generate exactly the same sequence of output events as existing secondaries then it must wait the warm up window length time you configure for the Oracle Stream Explorer high availability output adapter before it is available as a secondary To implement this high availability quality of service you configure your EPN with a high availability buffering output adapter with a sliding window of size greater than zero before each output adapter To reduce performance overhead rather than use a high availability input adapter use application time with some incoming event property For more information see e Choose an Adequate warm up window length Time e Configure Simple Failover With Buffering 17 7 3 Light Weight Queue Trimming This high availability quality of service is characterized by a low performance overhead faster recovery time and increased data integrity no missed events but a few duplicate events are possible during failover The active primary communicates to the secondaries the events that it has actually processed This enables the secondaries to trim their buffer of output events so that it contains only those events that have not
266. me refers to the actual server See Schema Reference for Oracle Stream Explorer for information about this file The information is provided for your information only Oracle does not recommend updating the deployments xml file manually Before you Begin Be sure you have configured Jetty for the Oracle Stream Explorer instance to which you are deploying your application For more information see Administering Oracle Stream Explorer Open a command window and update your CLASSPATH variable to include the wlevsdeploy jar JAR file which is in the following directory The Deployer utility is in the JAR file Oracle Middleware my_oep bin Deploy an OSGi Bundle with the Deployer Utility After the OSGi bundle successfully installs and all initialization tasks complete Oracle Stream Explorer starts the application and the adapter components listen for incoming events 1 Assemble your OSGi bundle as described in Assemble an OSGi Bundle with bundle sh 2 Open a command window and run the Deployer utility as follows Keep everything on one line prompt gt java jar wlevsdeploy jar url http host port wlevsdeployer user user password password install application_jar_file host The name of the computer where the Oracle Stream Explorer server is running port The port number where Oracle Stream Explorer listens The default value is 9002 This port is specified in the DOMAIN_DIR config file that describes the Oracle Stream Explo
267. mples domains and the user domains are located in ORACLE_CEP_HOME user_projects domains where ORACLE_CEP_HOME refers to the main Oracle Stream Explorer installation directory such as d oracle_cep 13 7 4 Access Third Party JAR Files with Xbootclasspath Update the start script by adding the xbootclasspath a option to the java command that executes the wlevs_2 0 jar file Set the KXbootclasspath a option to the full path name of the third party JAR files you want to access system wide For example if you want all deployed applications to be able to access a JAR file called e jars myExcitingJAR jar update the java command in the start script as follows The updated section is shown in bold in practice the command should be on one line JAVA_HOME bin java Dwlevs home USER_INSTALL_DIR Dbea home BEA_HOME Xbootclasspath a e jars myExcitingJAR jar jar SUSER_INSTALL_DIR bin wlevs_2 0 jar disablesecurity 1 2 3 4 oe 5 oe 6 13 7 5 Reference Foreign Stages You can refer to a stage that is in another Oracle Stream Explorer application A stage from another application is called a foreign stage When you assemble applications that depend on foreign stages be aware of class path dependencies Consider the application dependency graph that Figure 13 2 shows Figure 13 2 Foreign Stage Dependency Graph public Do public public Lor H public Long getVolume S l T Import Import Declare and E
268. mples source applications helloworld 13 7 1 Prepare and Organize the Files To bundle an application or library into an OSGi bundle manually you first need to prepare and organize the files to be bundled For simplicity this procedure creates a temporary directory that contains the required artifacts and then jars the contents of this temporary directory This is a suggested approach and you are not required to assemble the application this way 1 Create an empty directory such as output 13 6 Developing Applications for Event Processing with Oracle Stream Explorer Assemble an OSGi Bundle with bundle sh prompt gt mkdir output 2 Compile all application Java files into the output directory 3 Create an output META INF spring directory 4 Copy the EPN assembly file that describes the components of your application and how they are connected into the output META INF spring directory 5 Create an output META INF wlevs directory 6 Copy the XML files that configure the components of your application such as the processors or adapters into the output META INF wlevs directory 7 Create a MANIFEST MF file that contains information about the bundle See Create the MANIFEST MF File 8 If you need to access third party JAR files from your Oracle Stream Explorer application see Include Third Party JAR Files 9 Create a JAR file that contains the contents of the output directory Be sur
269. must have the JDK installed for this command to work because it depends on the Java compiler Note The appC tool does not support multiple component configuration files and multiple assembly files In this case use the bundle sh script or Oracle JDeveloper The appC tool validates the configuration and assembly files and the created OSGi bundle to ensure Oracle CQL validation and that the OSGi bundle deploys successfully Note Currently appC performs only schema validations with no extensive semantic validations Custom adapter providers are not validated 13 4 Developing Applications for Event Processing with Oracle Stream Explorer Assemble an OSGi Bundle with appC The appc jar file is located in Oracle Middleware my_oep bin Syntax java jar appC jar cmd cmd option basedir lt path to workspace gt arguments cmd options Choose one of the following command options to execute with the cmd argument buildA11 Creates the template generates the manifest and validates the component configuration file and the assembly file createTemplate Creates the workspace file structure with either input XML files or template XML files generateManifest Compiles the input source files and generates the OSGi manifest file based on resulting class files validate Validates the component configuration and assembly files against their schemas arguments cmd Execute one of the command options Specify the root
270. n A class that listens to a cache must implement an interface that provides methods for receiving events as follows e A class that listens to a Coherence cache must implement the com tangosol util MapListener interface e A class that listens to an Oracle Stream Explorer local cache must implement the com bea cache jcache CacheListener interface lt wlevs caching system id caching system id gt lt wlevs cache id cache id name alternative cache name gt lt wlevs caching system ref caching system id gt lt wlevs cache listener ref cache listener id gt lt wlevs cache gt lt bean id cacheListenerId class com bea wlevs example provider coherence gt In the example the cacheListenerId Spring bean listens to events coming from the cache In this case the user defined class that implements this component com bea wlevs example MyCacheListener is listening to an Oracle Coherence cache It must implement the appropriate Oracle Coherence specific Java interfaces including com tangosol util MapListener The following example illustrates this implementation package com bea wlevs example provider coherence import com tangosol util MapEvent import com tangosol util MapListener public class LocalListener implements MapListener public static int deleted 0 public static int inserted 0 public static int updated 0 public void entryDeleted MapEvent event deletedt public void entryInserted
271. n Oracle Middleware my_oep user_projects domains lt domain_name gt lt server_name gt config To use reference existing configuration file properties insert a ConfigurationPropertyPlaceholderConfigurer bean in the assembly file for your project as shown below lt bean class com bea wlevs spring support ConfigurationPropertyPlaceholderConfigurer gt For complete details see the com bea wlevs spring support ConfigurationPropertyPlaceholderCon figurer class in the Java API Reference for Oracle Stream Explorer 2 5 Resource Access Configuration Because Oracle Stream Explorer applications are low latency high performance event driven applications they run on a lightweight container and are developed with a POJO based programming model In POJO Plain Old Java Object programming business logic is implemented in the form of POJOs and then injected with the services they need This is popularly called dependency injection The injected services can range from those provided by Oracle Stream Explorer services such as configuration management to those provided by another Oracle product such as Oracle Kodo to those provided by a third party By using Oracle Stream Explorer and standard Java annotations and deployment XML you can configure the Oracle Stream Explorer Spring container to inject resources such as data sources or persistence managers and so on into your Oracle Stream Explorer application components The Spring co
272. nSource levs ede api StreamSender levs util Service 2 2 2 2 public class TradeEventSource implements RelationSource Variables for event type respository and event sender Both will be set by the server EventTypeRepository m_repos null RelationSender m_sender null Called by the server to set the repository instance Service public void setEventTypeRepository EventTypeRepository repos mM_repos repos Called by the server to set the sender instance Override public void setEventSender StreamSender sender Cast the received StreamSender to a RelationSender m_sender RelationSender sender Sends events to the next EPN stage using the sender received from the server This code assumes that an event instance isn t received from another part of the class instead creating a new instance from the repository private void sendEvents EventType eventType m_repos getEventType TradeEvent TradeEvent tradeEvent TradeEvent eventType createEvent m_sender sendDeleteEvent tradeEvent 7 8 Developing Applications for Event Processing with Oracle Stream Explorer 8 Cached Event Data You can configure a caching system so that applications have ready access to event data The caches in the system can be a combination of Oracle Coherence distributed caching Oracle Stream Explorer local caching and caching solutions provided by third parties You can acce
273. nally specifies the number of digits Oracle stores in the fractional part of the SECOND datetime field When you create a column of this data type the value can be a number in the range 0 to 9 The default value is 6 With local time zone TIMESTAMP fractional_seconds_precision WITH LOCAL TIME ZONE fractional_seconds_precision optionally specifies the number of digits Oracle stores in the fractional part of the SECOND datetime field When you create a column of this data type the value can be a number in the range 0 to 9 The default value is 6 3 7 Create and Register a JavaBean Event Type First identify the event data that the event type carries and then decide the properties the event type requires This section walks you through the following steps To make the JavaBean an event source or sink see Event Beans 3 7 1 Data Types You can use the following Java types for the properties e The fully qualified name of a Java class The name must conform to the Class forName rules and be available in the application class loader e A Java primitive such as int or float e An array by appending square brackets to the primitive or class name For example short or java lang Integer 3 7 2 Create a JavaBean Event Type Declaratively 1 Create a JavaBean class to represent your event type package com bea wlevs example algotrading event public final class MarketEvent private final Long timestam
274. nd events to the mediator JMS server with multiple threads which acts as an event source For more information on channel configuration to avoid see Customizing Oracle Stream Explorer e max threads in Schema Reference for Oracle Stream Explorer 17 8 2 8 3 Prefer Monotonic Event Identifiers Event identifiers can be monotonic or non monotonic A monotonic identifier is one that increases continually such as a time value A non monotonic identifier does not increase continually and may contain duplicates In general design your application with monotonic event identifiers With a monotonic event identifier the Oracle Stream Explorer high availability adapter can handle an application that may produce events out of order 17 8 2 9 Write Oracle CQL Queries with High Availability in Mind Not all Oracle CQL query usage is supported when using Oracle Stream Explorer high availability You might need to redefine your Oracle CQL queries to address these restrictions For more information see Oracle COL Query Restrictions 17 8 2 10 Avoid Coupling Servers The best high availability performance for Oracle Stream Explorer systems comes when servers can run without requiring coordination Generally this can be done when there is no shared state and the downstream system can tolerate duplicates Increasing levels of high availability are targeted at increasing the fidelity of event stream that the downstream system sees but the increa
275. nd data to the Oracle SOA Suite event network The EDN output adapter converts the Oracle Stream Explorer events into corresponding EDN events and publishes them to the EDN The published events can be new events that originate in the Oracle Stream Explorer application or EDN events that were received by the EDN input adapter processed by the Oracle Stream Explorer application and sent to the EDN output adapter 4 6 2 Create EDN Adapters The best way to create EDN adapters is through the Oracle JDeveloper components window The following assembly and configuration files generated by Oracle JDeveloper show the EDN inbound and outbound adapter configurations See Schema Reference for Oracle Stream Explorer for information about the SOA Suite side of the EDN adapter Assembly File The following assembly file entries show the elements and attribute settings for the inbound and outbound EDN adapters created in the Fraud Detection walkthrough from Getting Started with Event Processing for Oracle Stream Explorer e The input EDN adapter listens to the EDN input channel for events of type FraudCheckRequest e The EDN output adapter sends events of type FraudCheckRequest to the next stage in the EPN lt wlevs adapter id edn inbound adapter provider edn inbound gt lt wlevs listener ref ednInputChannel gt lt wlevs instance property name eventType value FraudCheckRequest gt lt wlevs adapter gt lt wlevs adapter id edn outb
276. nd loading a service class Cartridge Framework The com oracle cep cartridge package provides interfaces and classes that form the Data Cartridge Framework The Data Cartridge Framework is a service provider interface SPI that enables users and vendors to create cartridges to extend Oracle CQL functionality See Developing Applications with Oracle CQL Data Cartridges Spring Support The com bea wlevs spring support package provides interfaces and classes for using Spring functionality in Oracle Stream Explorer applications 1 7 Spring Framework The Spring Framework provides Java based APIs and a configuration model that you can use to create portable and flexible enterprise applications For more information about Spring e Spring Framework API 3 1 1 http docs spring io spring docs 3 1 1 RELEASE javadoc api e The Spring Framework Reference Documentation 3 1 http docs spring io spring docs 3 1 1 RELEASE spring framework reference html1 1 8 OSGi Service Platform The OSGi Service Platform provides a dynamic application execution environment where you can install update ore remove OSGI bundles modules dynamically For more information about OSGi e OSGi Release 4 Service Platform Javadoc http www osgi org Release4 Javadoc e OSGi Release 4 Core Specification http www osgi org osgi_technology download_specs asp section 2 Release4 Service Annotations Use the com bea
277. nd on one line java cp Oracle Middleware my_oep modules com bea core ws glassfish jaxws tools_12 0 0 0 jar com sun tools ws WsImport EchoService WSDL 3 Archive the generated class files the Oracle Stream Explorer application JAR file 4 Add the Export Package header and packages to the MANIFEST MF file to export the web services Java packages for the client code Export Package com oracle ocep sample echoService 5 Add the following packages to the MANIFEST MF file with the Import Package header Manifest Version 1 0 Export Package echo Bundle Vendor project vendor Bundle ClassPath lib echo jar Bundle Version 1 0 0 Bundle Localization bundle Bundle ManifestVersion 2 Bundle Name project name Import Package com bea wlevs configuration version 11 1 1 com bea w levs ede version 11 1 1 com bea wlevs ede api version 11 1 1 com bea wlevs ede impl version 11 1 1 com bea wlevs ede spi version 11 1 1 com bea wlevs management spi version 11 1 1 com bea wlevs spr ing version 11 1 1 com bea wlevs spring support version 11 1 1 co m bea wlevs util version 11 1 1 com ctc wstx stax version 4 0 5 c om sun xml bind v2 version 2 1 14 com sun xml bind v2 model annotat ion version 2 1 14 com sun xml messaging saaj soap version 2 1 0 com sun xml messaging saaj soap verl_l version 2 1 0 javax jws java x xml javax xml bind javax xml bind annotation javax xml namespace ja vax
278. nfigure an Oracle Coherence Caching System and Cache direct programming access to a cache are input and output adapters and business POJOs Additionally applications can access a cache from Oracle CQL either by a user defined function or directly from an Oracle CQL statement In the case of a user defined function programmers use Spring to inject the cache resource into the implementation of the function For more information see Application and Resource Configuration Applications can also query a cache directly from Oracle CQL statements that run in a processor In this case the cache functions as another type of data source to a processor so that querying a cache is similar to querying a channel except that data is pulled from a cache An example of using Oracle CQL to query a cache is from a financial application that publishes orders and the trades used to execute the orders to a cache At the end of the day when the markets close the application queries the cache to find all the trades related to a particular order e Update and delete data in a cache An Oracle Stream Explorer application can update and delete data in a cache when required For example a financial application might need to update an order in the cache each time individual trades that fulfill the order are executed or an order might need to be deleted if it has been cancelled The components of an application that are allowed to consume data from a cache are
279. ng messages ocep binding MaxThreads gt lt AD name Max Size id maxSize type Integer required true default 0 min 0 max 100 description The maximum size of the FIFO buffer for this channel ocep binding MaxSize gt lt AD name HEARTBEAT id heartbeat type Long required false default 5000000000 min 0 max 100000000000 description The value for the heartbeat timeout on this channel The default time unit is nanoseconds ocep binding HeartbeatTimeout gt lt OCD gt lt Designate pid helloworldInputChannel gt lt Object ocdref com oracle cep channel gt lt Designate gt lt Designate pid helloworldOutputChannel gt lt Object ocdref com oracle cep channel gt lt Designate gt 11 4 Developing Applications for Event Processing with Oracle Stream Explorer Deploy the HelloWorld Application 11 6 3 Oracle CQL Processor Query The following example shows how to configure an Oracle CQL processor query The ADs definition correspond to query parameters 1 and 2 in the sequence lt OCD name Product Filter id com oracle cep solution product filter ocep binding jmx CQLProcessor ocep multi valued true gt lt AD name range id range type Integer required true min 0 max 1000000000 default 10 description The range scope ocep binding Parameters gt lt AD name field id field type String required true default remainingQty description select one
280. ngen Utility Options Option Description build Generates all necessary files and compiles them Combines the i18n 110n keepgenerated and compile options d Specifies the root directory for the generated Java source files User targetdirecto catalog properties are placed in il8n_user properties relative ry to the targetdirectory Files are placed in appropriate directories based on the i118n_package and 110n_package values in the corresponding message catalog The default target directory is the current directory and is created as necessary If this argument is omitted all classes are generated in the current directory without regard to any class hierarchy described in the message catalog n Parse and validate but do not generate classes 12 6 Developing Applications for Event Processing with Oracle Stream Explorer Generate Localization Classes Option Description Keep generated Java source located in the same directory as the keepgenerated class files ignore Ignore errors i18n Generates internationalizers for example Loggers and TextFormatters 110n Generates localizers for example LogLocalizers and TextLocalizers compile Compiles generated Java files using the current CLASSPATH The resulting classes are placed in the directory identified by the d option The resulting classes are placed in the same directory as the source Errors detected during compilation generally result in
281. nk documentation 2 4 jpa extensions foe hti lt xml version 1 0 encoding UTF 8 gt lt persistence xmlns xsi http www w3 org 2001 XMLSchema instance xsi schemaLocation http java sun com xml ns persistence http java sun com xml ns persistence persistence_2_0 xsd version 2 0 xmlns http java sun com xml ns persistence gt lt persistence unit name helloworld transaction type RESOURCE_LOCAL gt lt class gt com bea wlevs event example helloworld HelloWorldEvent lt class gt lt properties gt lt property name eclipselink jdbc read connections min value 1 gt lt property name eclipselink jdbc write connections min value 1 gt lt lt property name eclipselink logging timestamp value false gt lt property name eclipselink logging thread value false gt lt property name eclipselink logging session value false gt lt property name eclipselink logging exceptions value false gt lt property name eclipselink logging connection value false gt lt property name eclipselink logging level value FINER gt gt lt properties gt lt persistence unit gt lt persistence gt 9 2 2 HelloWorldAdapter java The HelloWorldAdapter java class is a custom threaded adapter that continuously creates events of type HelloWorldEvent The application constructs 9 2 Developing Applications for Event Processing with Oracle Stream Explorer HelloWorld Example
282. nnel to your EPN In Figure 18 4 the channel is EventPartitionerChannel 10 Connect the channel to an upstream adapter In Figure 18 4 the upstream adapter is inbound 11 Connect the channel to two or more listeners In Figure 18 4 the channel is connected to Oracle CQL processors processor1 processor2 and processor3 If you want to the channel to perform load balancing each listener must be identical 12 Edit the EPN assembly file to add an eventPartitioner instance property to the channel element The value of this instance property is the fully qualified class name of the EventPartitioner instance the channel will use to partition events This class must be on your Oracle Stream Explorer application class path In this example the channel uses EventPartitioner instance com acme MyEventPartitioner to partition events lt wlevs channel id EventPartitionerChannel event type PriceEvent max threads 0 gt lt wlevs instance property name eventPartitioner value com acme MyEventPartitioner gt lt wlevs listener ref filterFanoutProcessor1 gt lt wlevs listener ref filterFanoutProcessor2 gt lt wlevs listener ref filterFanoutProcessor3 gt lt wlevs source ref PriceAdapter gt lt wlevs channel gt 18 14 Developing Applications for Event Processing with Oracle Stream Explorer
283. nt throughput and latency See Administering Oracle Stream Explorer Packages e com bea wlevs management package contains interfaces for managing constants used by client applications and to provide a super interface for all Oracle WebLogic Event Server MBeans e com bea wlevs management configuration package provides interfaces for managing applications adapters caches configuration Oracle CQL processors event beans stages streams and table sinks and sources e com bea wlevs management diagnostic package provides interfaces for managing diagnostic profiles A diagnostic profile is an XML file that contains application stage information for testing throughput and latency See Using Visualizer for Oracle Stream Explorer e com bea wlevs management diagnostic notification package provides a class for wrapping diagnostic change notifications sent by background probes See Using Visualizer for Oracle Stream Explorer e com bea wlevs diagnostic package provides interfaces and classes for listening for newly deployed applications and removed applications When applications are deployed and undeployed a profile manager group of diagnostic profiles is also created and removed and corresponding profile manager events are issued e com bea wlevs management runtime package provides interfaces for getting runtime information about the application the application Oracle CQL processors the domain the server and EPN stages e co
284. nt Configuration File Structure The wlevs_application_config xsd schema file describes the structure of component configuration files When you install Oracle Stream Explorer XSD files such as this one are included in the directory Oracle Middleware oep xsd This XSD schema imports the following schemas e wlevs_base_config xsd Defines common elements that are shared between application configuration files and the server configuration file e wlevs_eventstore_config xsd Defines event store specific elements e wlevs_diagnostic_config xsd Defines diagnostic elements See Schema Reference for Oracle Stream Explorer The structure of application configuration files is as follows There is a top level root element named config that contains a sequence of sub elements Each individual sub element contains the configuration data for an Oracle Stream Explorer component Oracle CQL processor channel or adapter For example lt xml version 1 0 encoding UTF 8 gt lt nl config xmlns nl http www bea com ns wlevs config application xmlns xsi http www w3 org 2001 XMLSchema instance gt lt processor gt lt name gt helloworldProcessor lt name gt lt rules gt lt query id helloworldRule gt lt CDATA select from helloworldInputChannel Now gt lt query gt lt rules gt lt processor gt lt channel gt lt name gt helloworldInputChannel lt name gt lt max size gt 10000 lt max size gt lt max threads gt 2 lt
285. nt Order e Configuration History e Assemble an OSGi Bundle with appC e Assemble an OSGi Bundle with bundle sh e Deploy an OSGi Bundle 13 1 OSGi bundles An OSGi bundle contains one or more JAR files that contain the Java classes packages and libraries that define an Oracle Stream Explorer application and its services and resources dependencies You can make the application services and resources available to other bundles You can also create an OSGi bundle that contains only services and resources that are used by other bundled applications For example an OSGi bundle can contain a JDBC driver that is accessed by other applications that execute in the same domain An OSGi bundle that contains an application and its resources is an application bundle and an OSGi bundle that contains only resources is an application library bundle An OSGi application bundle contains the following files e The compiled Java class files that implement the application components such as event types and event beans Assemble and Deploy 13 1 Application Dependencies One or more Oracle Stream Explorer configuration files that contain the component configurations Place the configuration files in the META INF wlevs directory of the OSGi bundle JAR file to deploy For example Oracle Middleware my_oep user_projects domains lt domain gt lt server gt applications lt OSGi_Bundle_Symbolic_Name gt If you have an application already
286. nt exception For more information see e Choose a Data Structure for the Event Type Reference Foreign Stages Java API Reference for Oracle Stream Explorer 3 12 Control Event Type Instantiation with an Event Type Builder Class You can create an event type builder to have more control over how event type instances are created For example using an event type builder you can ensure that the Events and Event Types 3 15 Control Event Type Instantiation with an Event Type Builder Class properties of a configured event are correctly bound to the properties of an event type class such as one you have implemented as a JavaBean You would need an event type builder in a case for example where event property names assumed in CQL code are different from the names of properties declared in the class For example assume the event type has a firstname property but the CQL rule that executes on the event type assumes the property is called fname Assume also that you cannot change either the event type class because you are using a shared event class from another bundle for example or the CQL rule to make them compatible with each other In this case you can use an event type builder factory to change the way the event type instance is created so that the property is named fname rather than firstname At runtime an event type builder class receives property values from the Oracle Event Processing server and uses those values to c
287. nt in tuning the maximum 18 2 Developing Applications for Event Processing with Oracle Stream Explorer Default Channel Scalability Settings number of threads it is reasonable to set it equal to the number of listeners on the channel In this example there are 3 listeners lt wlevs channel id EventPartitionerChannel event type PriceEvent max threads 3 gt lt wlevs instance property name eventPartitioner value true gt lt wlevs listener ref processorl gt lt wlevs listener ref processor2 gt lt wlevs listener ref processor3 gt lt wlevs source ref inbound gt lt wlevs channel gt 18 1 3 Configure Parallel Processing on the Upstream Adapter 1 Edit the EPN assembly file to configure the channel to set the max threads attribute to 0 lt wlevs channel id EventPartitionerChannel event type PriceEvent max threads 0 gt lt wlevs instance property name eventPartitioner value true gt lt wlevs listener ref processorl gt lt wlevs listener ref processor2 gt lt wlevs listener ref processor3 gt lt wlevs source ref inbound gt lt wlevs channel gt 2 Edit the Oracle Stream Explorer server file to add a work manager element Selecting the appropriate min threads constraint and max threads constraint for the work manager can depend on a number of factors including the factors discussed in Configure Parallel Processing on the Channel for setting thread counts
288. nt types JavaBean class Map and tuple The Event Inspector service converts events to the JavaScript Object Notation JSON format before publishing to the trace channel You must inject events in JSON format Note Byte arrays are not supported as property types in event types used with the event inspector JSON formatted events must conform to the structure Table 14 1 lists the required attributes event type myEventType operation insert binding outbound value firstname Jane lastname Doe phone code 12345 number office Table 14 2 Event Inspector JSON Event Required Attributes Attribute Description event The name of the Oracle Stream Explorer event as you defined it in the type application assembly file s event type repository Testing 1 2 3 14 5 Event Inspector Service Attribute Description operatio Specify the type of event n e insert insert event e delete delete event e update update event e heartbeat heartbeat event binding One of e inbound injected event e outbound trace event value One or more JSON formatted event properties as defined by the event type 14 2 2 HTTP Publish Subscribe Channel and Server The Event Inspector service uses a dynamic HTTP publish subscribe HTTP pub sub channel with the following name that is defined in the server config xm1 file SERVERNAME APPLICATIONNAME STAGENAME DIRECTIO
289. ntainer typically injects resources during component initialization However it can also inject and re inject resources at runtime and supports the use of JNDI lookups at runtime Oracle Stream Explorer supports the following types of resource access e Resource Access Annotations e Static Resource Injection e Dynamic Resource Injection e Dynamic Resource Lookup Using JNDI e Resource Name Resolution 2 6 Developing Applications for Event Processing with Oracle Stream Explorer Resource Access Configuration In the following sections consider the example resource that Example 2 2 shows This is a data source resource named StockDS that you specify in the Oracle Stream Explorer server file Example 2 2 Sample Resource Data Source StockDS lt config gt lt data source gt lt name gt StockDs lt name gt lt driver params gt lt url gt jdbc derby lt url gt lt driver params gt lt data source gt lt config gt 2 5 1 Resource Access Annotations Use the javax annotation Resource Resource annotation to configure resource access at design time and the corresponding deployment XML to override this configuration at deploy time 2 5 2 Static Resource Injection Static resource injection refers to the injection of resources during the initialization phase of the component life cycle Once injected resources are fixed or static while the component is active or running You can configure static resour
290. nterface to convert events to JSON messages See the Java API Reference for Oracle Stream Explorer for a full description of these APIs Inbound HTTP Pub Sub JSON Message The custom converter bean for an inbound HTTP pub sub JSON message implements the com bea wlevs adapters httppubsub api InboundMessageConverter interface This interface has only the convert method public List convert JSONObject message throws Exception The message parameter is the inbound HTTP pub sub message in JSON format The return value is a List of events to pass to the next node in the EPN Outbound HTTP Pub Sub JSON Message The custom converter bean for an outbound HTTP pub sub message implements the com bea wlevs adapters httppubsub api OutboundMessageConverter interface This interface has only the convert method public List lt JSONObject gt convert Object event throws Exception The event parameter is an event received by the outbound HTTP pub sub adapter from the source node in the EPN The return value is a List of JSON messages Example The following example shows a custom converter bean that implements both the InboundMessageConverter and OutboundMessageConvert interfaces You can use this bean for both inbound and outbound HTTP pub sub adapters Adapters 4 11 JMS Adapters Note You can use the GSON Java library to convert Java objects to JSON format For more information see http www json organdhttp code go
291. o specify the event type and the metadata file lt bean id mapperBean class com oracle cep mappers jaxb JAXBMapperImpl gt lt property name eventTypeName value CallCenterActivity gt lt property name metadata value external_metadata_casel xml gt lt bean gt If you want to call a factory to make the mapper bean specify the following for the bean element lt bean id mapperBean class com oracle cep mappers jaxb JAXBMapperFactory factorymethod create gt Configuration File The following configuration file entries specify properties for the mapper bean lt jaxb mapper gt lt name gt mapperBean lt name gt lt event type name gt CallCenterActivity lt event type name gt lt metadata gt external_metadata_casel xml lt metadata gt lt jaxb mapper gt Properties A mapper bean supports properties All of the properties except met adat aMap can be configured as assembly file properties or as elements in the configuration file 4 4 Developing Applications for Event Processing with Oracle Stream Explorer JAXB Support Table 4 1 Mapper Bean Properties and Elements Assembly File Property Name Configuration File Element Name Description eventlypeName contextPath validate schema event type name context path validate schema The name of an event type registered by the application in the event type repository The event type corresponds to a Java class The package n
292. of the MANIFEST MF file to specify their location in the JAR Operating System Path You can create an application library that depends on native code libraries that you do not choose to package as application libraries In this case you can put the native code libraries in the operating system path boot classpath of the Oracle Stream Explorer server When the server starts the library bundles that need to call this native code load the native code libraries For more information see Administering Oracle Stream Explorer Xbootclasspath If the JAR files include libraries used by all applications deployed to Oracle Stream Explorer such as JDBC drivers you can add the JAR file to the server s boot class path by specifying the Xbootclasspath a option to the java command in the scripts used to start up an instance of the server Assemble and Deploy 13 9 Assemble an OSGi Bundle with bundle sh Note This approach gives you little control over the order in which JAR files are loaded and dependency conflicts can occur Oracle recommends that you use the Oracle Stream Explorer server application library approach instead For more information see Operating System Path approach instead The name of the server start script is startwlevs cmd Windows or startwlevs sh UNIX and the script is located in the server directory of your domain directory The out of the box sample domains are located in ORACLE_CEP_HOME ocep_11 1 sa
293. ogic il8n L10nLookup Any errors warnings or informational messages are sent to stderr For user catalogs to be recognized the i18n_user properties file must reside ina directory identified in the Oracle Stream Explorer server class path Oracle recommends that the i18n_user properties file reside in the Oracle Stream Explorer server class path If the i18n_user properties file is in targetdirectory then targetdirectory should be in the Oracle Stream Explorer server class path Parse a Message Catalog to Generate the Logger and TextFormatter Classes The following steps summarize how to create an internationalized message to use with the Oracle Stream Explorer server 1 Create or edit a top level log message catalog or simple text message catalog by defining the messages in the catalog In addition to message text include information about the type and placement of runtime values that the message contains 2 Runweblogic il8ngen to validate the catalog you created or edited in Step 1 to generate the Logger and Text Formatter classes java weblogic il8ngen options filelist The generated classes contain a method for each message The class is defined according to information specified in the message catalog entry The classes include methods for logging or getting message text depending on the type of catalog The class name ends with Logger or TextFormatter For details see weblogic il8ngen Utility Table 12 1 weblogic i18
294. ogle com p google gson package com sample httppubsub import com bea wlevs adapters httppubsub api InboundMessageConverter import com bea wlevs adapters httppubsub api OutboundMessageConverter import com bea httppubsub json JSONObject import java util List import java util ArrayList import java util HashMap import java util Map public class TestConverter implements InboundMessageConverter OutboundMessageConverter public List convert JSONObject message throws Exception List eventCollection new ArrayList PubsubTestEvent event new PubsubTestEvent event setMessage From TestConverter message eventCollection add event return eventCollection public List lt JSONObject gt convert Object event throws Exception List lt JSONObject gt list new ArrayList lt JSONObject gt 1 Map map new HashMap Map put message PubsubTestEvent event getMessage list add new JSONObject map return list 4 10 JMS Adapters Use JMS adapters to connect the Java Message Service JMS with an Oracle Stream Explorer EPN to receive and send JMS messages The Oracle Stream Explorer JMS adapters support any JMS service provider that provides a Java client that is compliant with Java EE The JMS Inbound adapter converts the incoming JMS messages to Oracle Stream Explorer events and the JMS outbound adapter converts Oracle Stream Explorer events to JMS messages You can customize the inbound conversion by w
295. oid entryInserted MapEvent event verifyEventInStore event private void verifyEventInStore MapEvent event if event getNewValue instanceof SaleEvent System out println Unexpected type in SaleEvent cache return if m_entityMgr null setupEntityMgr EclipseLink JPA and Oracle Coherence 9 7 JPA Coherence Example SaleEvent sale SaleEvent event getNewValue Query q m_entityMgr createQuery SELECT s FROM SaleEvent s WHERE s itemID itemID q setParameter itemID sale getItemID List lt SaleEvent gt saleEvents q getResultList if saleEvents size 0 System out println ERROR Matched SaleEvent not found in store else System out printlin Found sale event for saleEvents get 0 getItemID for saleEvents get 0 getSalePrice m_sender sendInsertEvent sale private void setupEntityMgr m_entityMgrFactory Persistence createEntityManagerFactory PERSISTENCE_UNIT_NAME m_entityMgr m_entityMgrFactory createEntityManager public void entryUpdated MapEvent event verifyEventInStore event public void entryDeleted MapEvent event System out printin SaleEvent cache entry deleted Should not see this event for this sample 9 3 2 2 PriceTarget java package com oracle cep sample import javax persistence Entity import javax persistence Id Entity public class PriceTarget implements java io Serializable
296. olean boolean An instance of java lang Boolean BLOB byte Array of depth 1 of byte BOOLEAN java lang Boolean boolean An instance of java lang Boolean CHAR java lang Charact char An instance of er java lang Character CLOB byte Array of depth 1 of byte DATE java sql Date timestamp An instance of java sql Date 3 4 Developing Applications for Event Processing with Oracle Stream Explorer Design Constraints SQL Type Oracle Stream com bea wlevs ede api T Description Explorer Java Type ype DECIMAL java math BigDeci An instance of BINARY_DOUBL E or DOUBLE BINARY_FLOAT or FLOAT INTEGER JAVA_OBJECT LONGNVARCHAR LO Y GVARBINAR LONGVARCHAR CHAR CLOB UMERIC VARCHAR OTHER SMALLINT SQLXML IMESTAMP TINYINT VARBINARY VARCHAR mal java lang Double java lang Double java lang Integer java lang Object char byte char char byte java math BigDeci mal char java lang Object java lang Float java lang Integer xmltype java sql Time java sql Timestam p java lang Integer byte char double float int object char char char char object float int xmltype timestamp int char java math BigDecimal An instance of java lang Double An instance of java lang Double An instance of java lang Integer An instance of java lang Object
297. om a life cycle callback such as such as afterConfigurationActive or beforeResume You can call a method on a stream or relation source or sink from the run method of beans that implement RunnableBean See Event Beans 1 6 API Overview The APIs enable you to programmatically implement functionality for all aspects of Oracle Stream Explorer applications as described in this documentation set This section presents an overview of the API packages in terms of their intended usages and includes cross references to where you can learn more For the full reference documentation Javadocs for all classes and interfaces see Java API Reference for Oracle Stream Explorer See also Getting Started with Event Processing for Oracle Stream Explorer for sample code that uses the Oracle Stream Explorer APIs e Configuration e Adapters e ChannelsEvent Repositories e Event Driven Environment Introduction to Application Development 1 7 API Overview e Event Bean Life Cycle JAXB e Caching e Cache Loader e Cluster Group Management e Management Beans e High Availability e Testing and Utility Tools e Cartridge Framework e Spring Support Configuration The com bea wlevs configuration package provides interfaces to activate prepare and roll back configuration objects When you implement the Prepare interface provide a method that accepts checks and stores a configuration object The Java type of the configuration object i
298. on a channel and whether the work manager is dedicated to a specific adapter or shared with other components other adapters or the Jetty service As a starting point in tuning it is reasonable to set the min threads constraint and max threads constraint properties equal to the number of listeners downstream from the adapter if the work manager is dedicated to a single adapter instance If this work manager is not shared by more than one component that is it is dedicated to the upstream adapter in this configuration then set the min threads constraint and max threads constraint elements equal to the number of listeners lt work manager gt lt name gt adapt erWorkManager lt name gt lt min threads constraint gt 3 lt min threads constraint gt lt max threads constraint gt 3 lt max threads constraint gt lt work manager gt For more information see Schema Reference for Oracle Stream Explorer 3 Edit the component configuration file to configure the upstream adapter with this work manager lt adapter gt lt name gt inbound lt name gt lt work manager name gt adapterWorkManager lt work manager name gt lt adapter gt Scalable Applications 18 3 Partition an Incoming JMS Event Stream 18 1 4 Define a Local Partition Channel You must configure the Oracle COL Processor to support local partitioning Use the sample code given below to define local partitioning Example 18 1 Assembly File lt wl
299. on an appropriate event property as assembly file entries show For simple failover you can use system time stamps because events are not correlated between servers However it is possible that slightly different results might be output from the buffer if application time stamps are not used In this example event property arrivalTime is used The wlevs expression should be set to this event property lt w lt levs channel id helloworldInputChannel event type HelloWorldEvent gt lt wlevs listener ref helloworldProcessor gt lt wlevs source ref myHaInputAdapter gt lt wlevs application timestamped gt lt wlevs expression gt arrivalTime lt wlevs expression gt lt wlevs application timestamped gt wlevs channel gt 6 Configure the Oracle Stream Explorer high availability buffering output adapter Set the instance property windowLength to zero 0 as shown lt w 17 20 Developing Applic levs adapter id myHaSlidingWindowAdapter provider ha buffering gt lt wlevs listener gt ations for Event Processing with Oracle Stream Explorer Configure High Availability Quality of Service lt bean class com bea wlevs example helloworld HelloWorldBean gt lt wlevs listener gt lt wlevs instance property name windowLength value 0 gt lt wlevs adapter gt 7 Optionally configure the component configuration file to include the Oracle Stream Explorer high availability buffering output adap
300. on to use to create the messages event parameter An event received by the outbound JMS adapter from the source stage in the EPN 4 11 2 Implement the Inbound JMS Adapter This example shows you how to implement the convert method for the inbound JMS adapter 1 In Oracle JDeveloper add a Java class to your application project 2 Implement the com bea wlevs adapters jms api InboundMessageConverter interface The following example shows a possible implementation package com customer import com bea wlevs adapters jms api InboundMessageConverter import com bea wlevs adapters jms api MessageConverterException import com bea wlevs adapters jms api OutboundMessageConverter import javax jms JMSException import javax jms Message import javax jms Session import javax jms TextMessage import java util ArrayList import java util List public class MessageConverter implements InboundMessageConverter OutboundMessageConverter public List convert Message message throws MessageConverterException JMSException TestEvent event new TestEvent TextMessage textMessage TextMessage message event setString_1 textMessage getText List events new ArrayList 1 events add event return events public List lt Message gt convert Session session Object inputEvent Adapters 4 15 JMS Custom Message Converter Bean throws MessageConverterException JMSException TestEvent event TestEvent input
301. oncurrent consumers gt 1 lt concurrent consumers gt lt session transacted gt true lt session transacted gt lt message selector gt CONDITION lt message selector gt lt bindings gt lt group binding group id ActiveActiveGroupBean_group1 gt lt param id CONDITION gt acctid gt 400 lt param gt lt group binding gt lt group binding group id ActiveActiveGroupBean_group2 gt lt param id CONDITION gt acctid BETWEEN 301 AND 400 lt param gt lt group binding gt lt group binding group id ActiveActiveGroupBean_group3 gt lt param id CONDITION gt acctid BETWEEN 201 AND 300 lt param gt lt group binding gt lt group binding group id ActiveActiveGroupBean_group4 gt lt param id CONDITION gt acctid lt 200 lt param gt lt group binding gt lt bindings gt lt jms adapter gt In this configuration when the application is deployed to an Oracle Stream Explorer server with a cluster element groups child element that contains ActiveActiveGroupBean_groupl1 then the CONDITION parameter is defined as acctid gt 400 and the application processes events whose acct id property is greater than 400 Note Each in bound JMS adapter must listen to a different topic For more information see Adapters 6 Deploy your application to the deployment group of your multiserver domain At runtime each Oracle Stream Explorer server configures its instance of the application with the message selector that corresp
302. onds to its ActiveActiveGroupBean notification group This partitions the JMS topic so that each instance of the application processes a subset of the total number of messages in parallel 18 2 2 Configure Partitioning with High Availability This procedure uses the example application from Configure Precise Recovery With JMS Figure 18 2 shows the EPN diagram and Example 18 3 and Example 18 4 show the corresponding assembly and configuration files 18 6 Developing Applications for Event Processing with Oracle Stream Explorer Partition an Incoming JMS Event Stream Figure 18 2 IMSInboundAdapter IMSInboundAdapter2 myHalInputAdapter processor1 Event Input Precise Recovery With JMS EPN a gt b gt 2 channel channel2 myHaCorrelatingAdapter IMSOutboundAdapter clusterCorrelatingOutstream The procedure creates the Oracle Stream Explorer high availability configuration shown in Figure 18 3 Figure 18 3 ActiveActiveGroupBean With High Availability Deployment Group Notification Group 1 lt lt JMS Selector gt gt acctid lt 1000 lt lt JMS Selector gt gt acctid lt 1000 lt lt JMS Selector gt gt acctid gt 1000 lt lt JMS Selector gt gt acctid gt 1000 ActiveActiveGroupBean generated Notification Group Configure Scalability in a JMS Application with High Availability Create a multiserver domain In this example the deployment group is
303. operty named id and the event property that the high availability input adapter assigns a time value to is an event property named arrivalTime High Availability Applications 17 25 Configure High Availability Quality of Service lt wlevs adapter id myHaInputAdapter provider ha inbound gt lt wlevs instance property name keyProperties value id gt lt wlevs instance property name timeProperty value arrivalTime gt lt wlevs adapter gt This example shows a high availability input adapter configuration where the mandatory key is based on more than one event property properties orderID and account ID and the event property that the high availability input adapter assigns a time value to is an event property named arrivalTime lt wlevs adapter id myHaInputAdapter provider ha inbound gt lt wlevs instance property name timeProperty value arrivalTime gt lt wlevs instance property name keyClass value com acme MyCompoundKeyClass gt lt wlevs adapter gt A compound key Java class com acme MyCompoundKeyClass is mandatory and its implementation is shown The hashCode and equals methods are required When you specify a keyClass the keyProperties instance property is ignored Oracle Stream Explorer assumes that the compound key is based on all the getter methods in the keyClass package com acme public class MyCompoundKeyClass private int orderID private int accountID public MyCompoundKeyCl
304. or time range of fset but not both Specifies the number of events that Oracle Stream Explorer picks up in a single batch from the event buffer to write the event store Default value is 1000 Specifies the number of seconds that Oracle Stream Explorer waits for the event buffer window to fill up with the bat ch size number of events before writing to the event store Default value is 60 When specified Oracle Stream Explorer uses a stream when writing to the event store and this element specifies the size of the stream Non zero values indicate asynchronous writes Default value is 1024 When specified Oracle Stream Explorer uses a stream when writing to the event store and this element specifies the maximum number of threads to be used to process events for this stream Setting this value has no effect when max size is 0 The default value is 1 15 6 Developing Applications for Event Processing with Oracle Stream Explorer Configure a Component to Play Back Events 15 7 Configure a Component to Play Back Events You can configure any processor adapter channel or event bean in your application to play back events The component must downstream from the recording component so that the playback component can receive the events and play them back This section updates a channel configuration to play back events See Schema Reference for Oracle Stream Explorer for the complete XSD Schema that describes the event playb
305. ound adapter provider edn outbound gt lt wlevs instance property name eventType value FraudCheckResponse gt lt wlevs adapter gt Configuration file The following configuration file entries show the configuration settings for the EDN inbound and outbound EDN adapters created in the Fraud Detection walkthrough from Getting Started with Event Processing for Oracle Stream Explorer Note that you have to put the EDL and schema xsd files in the fixed path of the bundled JAR file lt edn adapter gt lt name gt edn outbound adapter lt name gt lt edl file gt FraudCheckEvent edl lt edl file gt lt validate gt false lt validate gt lt raw xml content gt false lt raw xml content gt lt jndi provider url gt t3 localhost 7101 lt jndi provider url gt lt jndi factory gt weblogic jndi WLInitialContextFactory lt jndi factory gt 4 8 Developing Applications for Event Processing with Oracle Stream Explorer File Adapter lt user gt weblogic lt user gt lt password gt welcomel lt password gt lt edn adapter gt lt edn adapter gt lt name gt edn inbound adapter lt name gt lt edl file gt FraudCheckEvent edl lt edl file gt lt schema file gt FraudCheckType xsd lt schema file gt lt validate gt false lt validate gt lt raw xml content gt false lt raw xml content gt lt jndi provider url gt t3 localhost 7101 lt jndi provider url gt lt jndi factory gt weblogic jndi WLInitialContextFactory lt jndi fa
306. output and data source has an associated event type For example one input can be a channel and another input can be a Coherence cache The channel and Coherence cache have different event types because the Coherence cache provides additional information to the Oracle CQL processor query that is related to but not the same as the event data coming from the input channel If you configure an Oracle CQL processor with more than one query by default all queries output their results to all of the output channels You can control which queries output their results to which output channels by putting a selector element on the downstream channel or channels Use the selector element to specify a space delimited list of one or more query names that can output their results to that channel The Oracle CQL query assigned to the output channel has the correct attributes to match the event type defined on the output channel For more information see Control Which Queries Output to a Downstream Channel 6 2 Assembly and Configuration Files When you add an Oracle CQL processor to your EPN the assembly file shows the following entry lt wlevs processor id processor gt When you add an Oracle CQL Pattern such as the Averaging Rule to the EPN in Oracle JDeveloper the assembly file shows the following entries lt wlevs processor id processor gt lt wlevs processor id averaging rule gt Configuration File When you add the Oracle CQL
307. ow to invoke services from an application and how to expose an application as a web service This chapter includes the following sections e Supported Platforms e Invoke a Web Service From an Application e Expose an Application as a Web Service 10 1 Supported Platforms Oracle Stream Explorer supports version 2 0 of the JAX WS API standard using the Glassfish reference implementation of JAX WS 2 0 including e JAX WS 2 0 Java API for XML Web Services defined in JSR 224 e WS I Basic Profile 1 1 e WS I Attachments Profile 1 0 SOAP Messages with Attachments e WS I Simple SOAP Binding Profile 1 0 e SOAP 1 1 and 1 2 Simple Object Access Protocol e MTOM Message Transmission Optimization Mechanism e WSDL 1 1 Web Services Definition Language e JAXB 2 0 Java API for XML Binding references through a separate JAXB module e SAAJ 1 3 SOAP with Attachments API for Java 10 2 Invoke a Web Service From an Application This procedure describes how to create an application that invokes a web service In this scenario the application is the web service client Invoke a Web Service from an Application 1 Create or obtain the web service definition language WSDL file for the web service This example uses a WSDL named EchoService WSDL Web Services 10 1 Expose an Application as a Web Service 2 Generate the compiled class files you need to invoke the Web Service with the following command Keep the entire comma
308. p private final String symbol private final Double price private final Long volume private final Long latencyTimestamp public MarketEvent public Double getPrice return this price public void setPrice Double price this price price public String getSymbol return this symbol public void setSymbol String symbol this symbol symbol 3 8 Developing Applications for Event Processing with Oracle Stream Explorer Create and Register a JavaBean Event Type public Long getTimestamp return this timestamp public void setTimestamp Long timestamp this timestamp timestamp public Long getLatencyTimestamp return this latencyTimestamp public void setLatencyTimestamp Long latencyTimestamp this latencyTimestamp latencyTimestamp public Long getVolume return this volume public void setVolume Long volume this volume volume Implementation for hashCode and equals methods 2 Compile the JavaBean class 3 Register your JavaBean event type in the Oracle Stream Explorer event type repository lt wlevs event type repository gt lt wlevs event type type name MarketEvent gt lt wlevs class gt com bea wlevs example algotrading event MarketEvent lt wlevs class gt lt wlevs event type gt lt wlevs event type repository gt 3 7 3 Create a JavaBean Event Type Programmatically 3 7 4 Usages Steps 1 and 2 are the same as steps 1 and
309. pe indicates graphical user interface elements associated with an action or terms defined in text or the glossary Italic type indicates book titles emphasis or placeholder variables for which you supply particular values Monospace type indicates commands within a paragraph URLs code in examples text that appears on the screen or text that you enter What s New in This Guide Screens shown in this guide may differ from your implementation depending on the skin used Any differences are cosmetic The following changes have been made in this document for the 12c 12 2 1 release Sections Description Entire Guide Product renamed to Oracle Stream Explorer xiii Part Application Development Part I contains the following chapters Introduction to Application Development Application and Resource Configuration Events and Event Types Adapters Channels Oracle COL Processors Event Beans Cached Event Data Web Services Parameterized Applications 1 Introduction to Application Development An Oracle Stream Explorer application monitors and processes streaming data in real time Streaming data flows into through and out of an application Raw data flows into the application and is converted into events Events flow through application stages for processing and filtering according to your application requirements At the end the application converts the processed and filtered events
310. plication A stage from another application is considered a foreign stage You do this by id attribute when you define both the source and target stage in the same application Note You cannot connect an Oracle CQL processor stage to a channel that is a foreign stage To refer to a stage you define in a different application you use the following syntax FOREIGN APPLICATION NAME FOREIGN STAGE ID Where FOREIGN APPLICATION NAME is the name of the application in which you defined the foreign stage and FOREIGN STAGE ID is the id attribute of the foreign stage The following example shows how the reference in application to the foreign stage Hel loWorldBeanSource that you define in application application2 lt wlevs stream id helloworldInstream gt lt wlevs listener ref helloworldProcessor gt lt wlevs source ref application2 HelloWorldBeanSource gt lt wlevs stream gt lt wlevs event bean id HelloWorldBeanSource class com bea wlevs example helloworld HelloWorldBeanSource advertise true gt The following stages cannot be foreign stages 2 4 Developing Applications for Event Processing with Oracle Stream Explorer Component Configuration File Structure e Cache When creating Oracle Stream Explorer applications with foreign stages you must consider foreign stage dependencies when assembling deploying and redeploying your application For more information see Reference Foreign Stages 2 3 Compone
311. plorer high availability buffering output adapter wlevs instance Specify one or more instance property element name and property value attributes as Table 17 7 describes Table 17 7 lists the instance properties Table 17 7 Instance Properties Name Value windowLength Specify the sliding window size as an integer number of milliseconds Default 15000 Configuration File The root element for configuring an Oracle Stream Explorer high availability buffering output adapter is ha buffering adapter The name child element for a particular adapter must match the id attribute of the corresponding wlevs adapter element in the assembly file as shown lt ha ha buffering adapter gt lt name gt mySlidingWindowingAdapter lt name gt lt window length gt 15000 lt window length gt lt warm up window length units minutes gt 6 lt warm up window length gt lt ha ha buffering adapter gt Table 17 8 describes the additional child elements of ha buffering adapter you can configure for an Oracle Stream Explorer high availability buffering output adapter Table 17 8 Child Elements Child Element Description window length Specify the sliding window size as an integer number of milliseconds Default 15000 warm up window Specify the length of time that the high availability input adapter length can be idle before it generates a heartbeat event to advance tim Valid integer values for the units attribute
312. processor to your EPN the configuration file shows the following entry By default you get a template for rules that contains a template for one query lt processor gt lt name gt processor lt name gt lt rules gt lt query id ExampleQuery gt lt CDATA select from MyChannel now gt lt query gt lt rules gt lt processor gt e The rules element groups the Oracle CQL statements that the Oracle CQL statements this processor executes e The query element contains Oracle CQL select statements The query element id attribute defines the query name e The XML CDATA type indicates where to put the Oracle CQL rule e The select statement is the actual query The template provides the now operator so that you can perform a now operation as described in NOW and Last Event Windows 6 2 Developing Applications for Event Processing with Oracle Stream Explorer Queries 6 3 Queries The following sections show how to perform basic Oracle CQL processor queries on stock trade events e Stream Channels e Time Based Relations Windows e Processor Output Control Slides Objective The objective for this section is understand how to use windows slides and views in Oracle CQL queries e Windows convert event streams to time based event relations to make it possible to perform Oracle CQL operations on the events See Time Based Relations Windows e Slides enable you to batch events to control how the rate at
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314. properties for particular run of the load generator Oracle Stream Explorer provides a default property file you can use if the default property values are adequate See Create the Properties File 2 Create a file that contains the actual data feed values See Create the Data Feed File 3 Configure the csvgen adapter so that it correctly reads the data feed generated by the load generator See Configure the csvgen Adapter in Your Application 4 Run the load generator and specify the properties file you created in step 1 to begin the simulated data feed For example if the name of your properties file is c loadgen myDataFeed prop execute the following command Testing 1 2 3 14 1 Load Generator and the csvgen Adapter prompt gt runloadgen cmd c loadgen myDataFeed prop If you redeploy your application you must also restart the load generator 5 To stop and load generator go to directory where you have load generator running and type ctrl c 14 1 1 Create the Properties File Oracle Stream Explorer provides a default properties file called csvgen prop in the Oracle Middleware my_oep utils load generator directory The format of the file is simple each property value pair is on its own line The following example shows the default csvgen prop file Oracle recommends you use this file as a template for your own property file name of file containing your test data test csvDataFile test csv port the server will
315. ption specifies a JAR file that is an Oracle driver located in directory C drivers The name of the generated bundle JAR is the concatenation of the name and version arguments oraclel0g_11 2 0 jar and is created in the C stage directory The bundle JAR contains the following files 1465 Thu Jun 29 17 54 04 EDT 2006 META INF MANIFEST MF 1540457 Thu May 11 00 37 46 EDT 2006 com oracle ojdbcl4_11 2 0 Jjar 1700 Thu Jun 29 17 54 04 EDT 2006 com bea core tools bundler Activator class The factory option specifies that there are two factory classes to be instantiated and registered as an OSGi service when the bundle activates each under a separate object class as Table 13 2 shows Table 13 2 Factory Class and Service Interfaces Factory Class Service Interface oracle jdbc xa client OraclexXADataSource javax sql XADataSource oracle jdbc OracleDriver java sql Driver The service option registers services with a name property set to oraclel2c and a version property with a value of 12 1 3 0 The following example shows the Oracle Stream Explorer server log messages with the service registrations INFO Jun 29 2006 5 54 18 PM Service REGISTERED version 12 1 3 0 name oraclel2c objectClass javax sql XADataSource service id 23 INFO Jun 29 2006 5 54 18 PM Service REGISTERED version 12 1 3 0 name oraclel2c objectClass java sql Driver service id 24 INFO Jun 29 2006 5 54 18 PM Bundle oraclellg STARTED
316. queue trimming using the Oracle Stream Explorer high availability input adapter and the broadcast output adapter This procedure starts with the example EPN that Figure 17 11 shows and adds the required components to configure it for light weight queue trimming Figure 17 11 Light Weight Queue Trimming EPN p gt 2 gt _B helloworldInputChannel helloworldOutputChannel helloworldAdapter helloworldProcessor HelloWorldBean Configure light weight queue trimming 1 Create a multiserver domain using Oracle Coherence For more information see Administering Oracle Stream Explorer 2 Create an Oracle Stream Explorer application 3 Edit the MANIFEST MF file to add the following Import Package entries e com bea wlevs ede api cluster High Availability Applications 17 23 Configure High Availability Quality of Service e com oracle cep cluster hagroups e com oracle cep cluster ha adapter e com oracle cep cluster ha api 4 Configure your Oracle Stream Explorer application EPN assembly file to add an Oracle Stream Explorer high availability input adapter as the following example shows e Addawlevs adapter element with provider set to ha inbound after the regular input adapter he loworldAdapter e Addawlevs listener element to the regular input adapter helloworldAdapter that references the ha inbound adapter by its id e Addawlevs source element to the helloworldInputChannel that references the ha inbound adapter by it
317. r gt server 3 lt server name gt ocep server 3 lt server name gt lt enabled gt coherence lt enabled gt lt groups gt MyDeploymentGroup ActiveActiveGroupBean_group3 lt groups gt lt cluster gt ocep lt cluster gt server 4 lt server name gt ocep server 4 lt server name gt lt enabled gt coherence lt enabled gt lt groups gt MyDeploymentGroup ActiveActiveGroupBean_group4 lt groups gt lt cluster gt Create an Oracle Stream Explorer application Add an Act iveAct iveGroupBean element to the assembly file as follows lt bean id clusterAdapter class com oracle cep cluster hagroups ActiveActiveGroupBean gt lt bean gt Define a parameterized message selector in the jms adapter element for the JMS inbound adapters a Edit the component configuration file to add group binding child elements to the jms adapter element for the JMS inbound adapters Scalable Applications 18 5 Partition an Incoming JMS Event Stream b Add one group binding element for each possible JMS message selector value as shown lt jms adapter gt lt name gt JMS InboundAdapter lt name gt lt event type gt StockTick lt event type gt lt jndi provider url gt t3 ppurich pce 7001 lt jndi provider url gt lt destination jndi name gt Topicl lt destination jndi name gt lt user gt weblogic lt user gt lt password gt weblogicl lt password gt lt work manager gt Jett yWorkManager lt work manager gt lt c
318. r ha adapter e com oracle cep cluster ha api High Availability Applications 17 21 Configure High Availability Quality of Service 4 Configure your Oracle Stream Explorer application EPN assembly file to add an Oracle Stream Explorer high availability buffering output adapter as the following assembly file entries show e Addawlevs adapter element with provider set to ha buf fering after channel hel loworldOutputChannel e Update the wlevs listener element in channel helloworldOutputChannel to reference the ha buf fering adapter by its id e Addawlevs listener element to the ha buffering adapter that references the Hel 1oWorldBean class lt wlevs event type repository gt lt wlevs event type type name HelloWorldEvent gt lt wlevs class gt com bea wlevs event example helloworld HelloWorldEvent lt wlevs class gt lt wlevs event type gt lt wlevs event type repository gt lt wlevs adapter id helloworldAdapter class com bea wlevs adapter example helloworld HelloWorldAdapter gt lt wlevs instance property name message value HelloWorld the current time is gt lt wlevs adapter gt lt wlevs channel id helloworldInputChannel event type HelloWorldEvent gt lt wlevs listener ref helloworldProcessor gt lt wlevs channel gt lt wlevs processor id helloworldProcessor gt lt wlevs channel id helloworldOutputChannel event type HelloWorldEvent advertise true gt lt wlevs listener ref
319. r scheme RefreshMessageStoreAt Logon Y SocketConnectPort1 8392 SocketConnectHost1 8 8 8 8 SocketConnectPort2 2932 SocketConnectHost2 12 12 12 12 4 14 REST Adapter The Representational State Transfer REST inbound adapter receives HTTP Post data from an external client through the HTTP protocol A REST adapter can accept data in the following forms and convert that data into the Oracle Stream Explorer event configured on the inbound REST adapter XML CSV and JavaScript Object Notation JSON To convert data to events the REST adapter requires a Java Architecture for XML Binding JAXB mapper and a CSV mapper A mapper is a JavaBean class that implements the marshalling and unmarshalling of the incoming data Oracle JDeveloper does not currently provide a component for the REST adapter However you can create a REST adapter by adding entries to the assembly and configuration files for your Oracle Stream Explorer application Assembly File The following assembly file shows the settings for an inbound REST adapter that handles input data of type XML CSV and JSON lt bean id xmlMapperBean class com oracle cep mappers jaxb JAXBMapperFactory factory method create gt lt bean id csvMapperBean class com oracle cep mappers csv CSVMapper gt lt bean id jsonMapperBean class com oracle cep mappers jaxb JAXBMapperFactory factory method create gt lt wlevs adapter id restInbound provider rest inbound gt
320. r set to ha correlating after channel channel2 e Update the wlevs listener element in channel channe12 to reference the ha correlating adapter by its id e Addawlevs listener element to the ha correlating adapter that references the regular output adapter JMSOutboundAdapter lt wlevs event type repository gt lt wlevs event type type name StockTick gt lt wlevs properties gt lt wlevs property name lastPrice type double gt lt wlevs property name symbol type char gt lt wlevs properties gt lt wlevs event type gt lt wlevs event type repository gt lt wlevs adapter id JMSInboundAdapter provider jms inbound gt lt wlevs listener ref myHaInputAdapter gt lt wlevs adapter gt lt wlevs adapter id myHaInputAdapter provider ha inbound gt lt wlevs adapter gt lt wlevs channel id channell event type StockTick gt lt wlevs listener ref processorl gt lt wlevs source ref myHalInputAdapter gt lt wlevs channel gt lt wlevs processor id processorl gt lt wlevs listener ref channel2 gt lt wlevs processor gt lt wlevs channel id channel2 event type StockTick gt lt wlevs listener ref myHaCorrelatingAdapter gt lt wlevs channel gt lt wlevs adapter id myHaCorrelatingAdapter provider ha correlating gt lt wlevs listener ref JMSOutboundAdapter gt lt wlevs adapter gt lt wlevs adapter id JMSOutboundAdapter provider jms outbound gt
321. rce Access Configuration for information about using Oracle Stream Explorer annotations and deployment XML to configure resource injection Event Bean Life Cycle The com bea wlevs ede api package also enables control over event bean life cycle You can manage event bean initialization configure dynamic activation use threading suspend and resume processing and release resources when the application is undeployed See Application Life Cycle for information about the event bean and application life cycles Note that the Spring framework implements similar bean life cycle interfaces However the equivalent Spring interfaces do not allow you to manipulate beans that were created by factories while the Oracle Stream Explorer interfaces do JAXB Oracle Stream Explorer provides a simplified interface for using Java Architecture for XML Binding JAXB mapping capabilities in adapters and event beans to marshall and unmarshall event data between XML and Java objects See JAXB Support Packages e com oracle cep mappers api package provides interfaces for marshalling and unmarshalling event data for most applications requirements e com oracle cep mappers jaxb package provides interfaces that provide specialized method signatures for marshalling and unmarshalling Caching You can configure a caching system so that applications have ready access to event data The caches in the system can be a combination of Oracle Coherence distributed
322. re class com bea wlevs example provider coherence LocalStore gt Example 8 4 Oracle Coherence Cache LocalStore Implementation package com bea wlevs example provider coherence import java util Collection import java util HashMap import java util Map import java util Set import com bea wlevs example provider event ProviderData 8 16 Developing Applications for Event Processing with Oracle Stream Explorer Access a Cache from Application Code import com tangosol net cache CacheStore public class LocalStore implements CacheStore public static int eraseCount 0 public static int storeCount 0 public static int loadCount 0 public void erase Object key eraseCountt t public void eraseAll Collection keys for Object key keys erase key public void store Object key Object value Do the store operation here public void storeAll Map entries for Map Entry entry Set lt Map Entry gt entries entrySet store entry getKey entry getValue public Object load Object key loadCount return new ProviderData String key public Map loadAll Collection keys Map result new HashMap for Object key keys result put key load key return result 8 10 Access a Cache from Application Code Once you have configured a cache you can access the cache from several components in an Oracle Stream Explorer application This section desc
323. re Simple Failover With Buffering e Configure Light Weight Queue Trimming e Configure Precise Recovery With JMS 17 9 1 Configure a Simple Failover You configure simple failover with the Oracle Stream Explorer high availability buffering output adapter with a sliding window size of zero 0 This procedure starts with the example EPN that Figure 17 9 shows and adds the required components to configure it for a simple failover Figure 17 9 Simple Failover EPN B X Ji helloworldInputChannel i helloworldOutputChannel helloworldAdapter helloworldProcessor HelloWorldBean Configure a simple failover 1 Create a multiserver domain using Oracle Coherence For more information see Administering Oracle Stream Explorer 2 Create an Oracle Stream Explorer application 3 Edit the MANIFEST MF file to add the following Import Package entries e com bea wlevs ede api cluster e com oracle cep cluster hagroups e com oracle cep cluster ha adapter e com oracle cep cluster ha api 4 Configure your Oracle Stream Explorer application EPN assembly file to add an Oracle Stream Explorer high availability buffering output adapter as the following assembly file entries show High Availability Applications 17 19 Configure High Availability Quality of Service lt w Adda wlevs adapter element with provider set to ha buffering after channel hel loworldOutputChannel Update the wlevs listener element in channel helloworldOutputCh
324. ream Explorer high availability adapters in the EPN assembly file and component configuration files similar to how you configure other components in the EPN such as channels or processors After making any Oracle Stream Explorer high availability configuration changes you must redeploy your Oracle Stream Explorer application See Deploy an OSGi Bundle This section includes the following procedures e Configure the High Availability Input Adapter e Configure the Buffering Output Adapter e Configure the Broadcast Output Adapter e Configure the Correlating Output Adapter 17 10 1 Configure the High Availability Input Adapter The Oracle Stream Explorer high availability broadcast input adapter is implemented by the Broadcast InputAdapter interface Assembly File The root element to declare an Oracle Stream Explorer high availability input adapter is wlevs adapter with the provider element set to ha inbound You also specify 17 34 Developing Applications for Event Processing with Oracle Stream Explorer Configure High Availability Adapters a wlevs listener element for the Oracle Stream Explorer high availability input adapter in the input adapter lt wlevs adapter id jmsAdapter provider jms inbound lt wlevs listener ref myHaInputAdapter gt lt wlevs adapter gt lt wlevs adapter id myHaInputAdapter provider ha inbound gt lt wlevs instance property name keyProperties value id gt lt wlevs instance prope
325. ream stage is an Oracle CQL processor For more information see Oracle CQL Processors 5 4 Batch Processing Channels By default a channel processes events as they arrive You can configure a channel to batch events that have the same time stamp and were output from the same query by setting the wlevs channel attribute batching to true Batching events can improve application performance lt wlevs channel id priceStream event type PriceEvent batching true gt lt wlevs listener ref filterFanoutProcessor gt lt wlevs source ref PriceAdapter gt lt wlevs channel gt For related information see Implement RelationSender and bat ching in Schema Reference for Oracle Stream Explorer 5 5 Fault Handling You can write code to handle exceptions that occur in stages that are downstream from a channel and thrown to the channel By default the fault handling behavior for a channel is as follows e Ifthe channel max threads setting is 0 a pass through channel then the exception is thrown again to the next upstream stage in the EPN e Ifthe channel max threads setting is greater than 0 then the exception is logged and dropped any events associated with the fault are also logged and dropped You can write a fault handling class and associate the handler with a channel with max threads values that are greater than 0 With a fault handler associated with the 5 4 Developing Applications for Event Processing with Ora
326. reate an instance of the event type class you created Your event type builder then returns the instance to the server In this way your builder class is in effect an intermediary instantiating event types in cases where the server is unable to determine how to map configured properties to event type properties Creating and using an event type builder involves implementing the builder class and configuring a JavaBean event type to use the builder as described in the following sections e Implement an Event Type Builder Class e An Event Type that Uses an Event Type Builder 3 12 1 Implement an Event Type Builder Class When you program the event type builder factory you must implement the EventBuilder Factory inner interface of the com bea wlevs ede api EventBuilder interface see the Java API Reference for Oracle Stream Explorer for details about the methods you must implement such as createBuilder and createEvent The following example of an event type builder factory class is taken from the FX sample package com bea wlevs example fx import java util HashMap import java util Map import com bea wlevs ede api EventBuilder import com bea wlevs example fx OutputBean ForeignExchangeEvent public class ForeignExchangeBuilderFactory implements EventBuilder Factory Called by the server to get an instance of this builder public EventBuilder createBuilder return new ForeignExchangeBuilder Inn
327. rer applications If your library is a driver such as a JDBC driver put the library in the library extensions directory so it activates in the correct order 13 3 2 Library Extensions Directory By default the Oracle Stream Explorer server library extensions directory is DOMAIN_DIR servername modules ext For example Oracle Middleware my_oep user_projects domains mydomain myserver modules ext Oracle Stream Explorer loads the libraries in the library extensions directory first at the same time as the Oracle Stream Explorer server core modules Put drivers in the library extensions library to activate them first to override an older driver or to provide access to an alternative driver If your library is not a driver put it in the library directory For more information see Administering Oracle Stream Explorer 13 4 Deployment Order The Oracle Stream Explorer server loads components in the following order at Oracle Stream Explorer server start up time 1 Load libraries in the library extensions directory 2 Load libraries in the library directory 3 Load Oracle Stream Explorer applications Assemble and Deploy 13 3 Configuration History The Oracle Stream Explorer server loads libraries from both the library extensions directory and the library directory based on the lexical order of the library names Lexical ordering includes the relative directory name plus JAR file name For example e modules a jar starts before
328. rer domain The port number is the value of the lt Port gt child element of the lt Net io gt element in the file lt Netio gt lt Name gt Net 10 lt Name gt lt Port gt 9002 lt Port gt lt Netio gt 13 14 Developing Applications for Event Processing with Oracle Stream Explorer Deploy an OSGi Bundle user The user name of the Oracle Stream Explorer administrator password The password of the Oracle Stream Explorer administrator application_jar_file The OSGi bundle The OSGi bundle must be located on the same computer where you execute the Deployer utility For example if Oracle Stream Explorer is running on host ariel listening on port 9002 user name and password of the administrator is wlevs wlevs and your application JAR file is called myapp_1 0 0 0 jar and is located in the applications directory then the command is the following Keep everything on one line prompt gt java jar wlevsdeploy jar url http ariel 9002 wlevsdeployer user wlevs password wlevs install applications myapp_1 0 0 0 jar The Deployer utility provides additional options over what was described here to resume suspend update uninstall and deploy an OSGi bundle to a specified group of multiserver domains For more information see Administering Oracle Stream Explorer Assemble and Deploy 13 15 Deploy an OSGi Bundle 13 16 Developing Applications for Event Processing with Oracle Stream Explorer 14 Testing 1 2 3 Orac
329. ribe server associated with the Oracle Stream Explorer instance hosting the current Oracle Stream Explorer application By default each Oracle Stream Explorer server is configured with an HTTP Publish Subscribe server with path pubsub If you have created a new local HTTP Publish Subscribe server or changed the default configuration then specify the location of the server in the server file In the file specify the ht tp pubsub element path value with the location of the server You can locate the server file in your Oracle Stream Explorer installation at Oracle Middleware my_oep examples domains lt my_domain gt defaultserver The channel child element specifies the channel that the adapter publishes or subscribes to lt http pub sub adapter gt lt name gt http pub adapter lt name gt lt server url gt http myhost com 9102 pubsub lt server url gt lt channel gt channel2 lt channel gt lt event type gt com mycompany httppubsub PubsubEvent lt event type gt lt user gt wlevs lt user gt lt password gt wlevs lt password gt lt http pub sub adapter gt lt http pub sub adapter gt lt name gt http sub adapter lt name gt lt server url gt http myhost com 9102 pubsub lt server url gt lt channel gt channel2 lt channel gt lt event type gt com mycompany httppubsub PubsubEvent lt event type gt lt http pub sub adapter gt 4 9 HTTP Publish Subscribe Adapter Custom Converter Bean The HTTP Publis
330. ribes how to do that For more information see the following sections e Access a Cache from an Oracle COL Statement e Access a Cache from an Adapter e Access a Cache From a Business POJO e Access a Cache From an Oracle CQL User Defined Function e Access a Cache with JMX Before you assemble and deploy the application edit your META INF MANIFEST ME file to import packages that are required in your implementation For example if your application implements cache listeners loaders or stores your manifest should import com tangosol net cache packages which contain the Coherence APIs Oracle Stream Explorer provides caching APIs that you can use in your application to perform certain tasks The APIs are in the com bea cache jcache package which includes the APIs used to access a cache and create cache loader listeners and stores If you want to use the loader listener and store functionality then import the com tangosol net and com tangosol net cache packages Cached Event Data 8 17 Access a Cache from Application Code You create configure and wire caching systems and caches with the EPN assembly file and component configuration files This means that you typically never explicitly use the Cache and CachingSystem interfaces in your application The only reason to use them is when you have additional requirements over the standard configuration For example if you want to provide integration with a third part
331. ries lt processor gt lt rules gt lt query id rule2 lt CDATA ISTREAM SELECT AVG price FROM StockTradeIStreamChannel RANGE 1 MIN gt lt query gt lt rules gt lt processor gt Note Very large numbers must be suffixed Without the suffix Java treats very large numbers like an integer and the value might be out of range for an integer which throws an error Add a suffix as follows 1 or L for Longf or F for floatd or D for doublen or N for big decimal For example SELECT FROM channel0 RANGE 13684301070270000001 nanoseconds ROW Operator You can specify a tuple based window with the time based ROWS operator as follows SELECT AVG price FROM StockTradeIStreamChannel ROWS 3 A tuple is an event so the ROWS 3 operation means to average the price on three events in the relation starting when the first event arrives The way it works is that the average operation is performed on the first event that enters the relation When the second event enters the relation the average operation is performed on the two events When the third event enters the relation the average operation is performed on the three events No averaging occurs again until the fourth event enters the relation When the fourth event enters the relation the second third and fourth events are averaged Likewise when the fifth event enters the relation the third fourth and fifth events are averaged The prior examples
332. rims all events in its queue generated prior to event c including event c itself In this case the set of events trimmed willbe a b e d c which is wrong because the primary server has not yet output events d and e Ifa failover occurs after processing the trimming message for event c events are lost 17 8 2 8 1 Prefer Deterministic Behavior For an application to generate events in the same order when run on multiple instances it must be deterministic The application must not rely on things like e Random number generators that can return different results on different machines e Methods like System getTimeMillis or System nanoTime that can return different results on different machines because the system clocks are not synchronized 17 16 Developing Applications for Event Processing with Oracle Stream Explorer Design Applications for High Availability 17 8 2 8 2 Avoid Multithreading Because thread scheduling algorithms are very timing dependent multithreading can be a source of nondeterministic behavior in applications Different threads can be scheduled at different times on different machines For example avoid creating an EPN in which multiple threads send events to a high availability adapter in parallel If such a channel is an event source for a high availability adapter it would cause events to be sent to the adapter in parallel by different threads and could make the event order nondeterministic Also do not se
333. riting your own Java class See Customizing Oracle Stream Explorer The best way to create JMS adapters is through the Oracle JDeveloper components window The following assembly and configuration files generated by Oracle JDeveloper show the JMS inbound and outbound adapter configurations Note An exception that occurs in the MessageConverter object associated with a outbound JMS adapter does not cause the underlying JMS transaction to roll back If the exception occurs outside of the MessageConverter object within the outbound JMS adapter then an existing JMS transaction is rolled back 4 10 1 Service Providers Oracle Stream Explorer is tested against the following service providers 4 12 Developing Applications for Event Processing with Oracle Stream Explorer JMS Adapters e WebLogic T3 Client which is a Java RMI client that uses Oracle T3 protocol to communicate with Oracle WebLogic Server e Version 10 0 10 3 and 10 3 1 of Oracle WebLogic Server JMS e The current version of Tibco EMS JMS If the service provider you want to use is not in the list you can configure Oracle Stream Explorer JMS adapters for use with your service provider by contacting your service provider and getting the jndi provider url and jndi factory information needed for the jms adapter configuration 4 10 2 Inbound Adapter Configuration Assembly File lt wlevs adapter id jms inbound adapter provider jms inbound gt Confi
334. rk add a wait period before the application begins to receive events In the following example the EPN assembly file excerpt shows a service element stanza that registers the SimpleFaultHandler class as the fault handler for the Oracle CQL processor with an id of exampleProcessor lt osgi service interface com bea wlevs ede api FaultHandler gt lt osgi service properties gt lt entry key application identity value myapp gt lt entry key stage identity value exampleProcessor gt lt osgi service properties gt lt bean class com example faulthandler SimpleFaultHandler gt lt osgi service gt lt A processor with a user defined function gt lt wlevs processor id exampleProcessor gt Oracle CQL Processors 6 17 Fault Handling lt wlevs processor gt For more on the schema for registering OSGi services see http static springsource org osgi docs 1 1 x reference html appendix schema htm1 For more on OSGi see http en wikipedia org wiki OSGi 6 18 Developing Applications for Event Processing with Oracle Stream Explorer l Event Beans Java is the language you use to write logic for event bean and Spring bean components to add to the EPN Use an event bean in your EPN to define application logic that works on event data Use a Spring bean in your EPN when your deployment context and the features you want to use are based on Spring Event bean application logic functions as an event
335. rkeley database instance or to set the cache size to tune performance To configure an event store for Oracle Stream Explorer server 1 Stop the Oracle Stream Explorer server instance if it is running 2 Open the server config xml file for editing The file is located in Oracle Middleware my_oep user_projects domains lt domain_name gt lt server_name gt config 3 Edit the bdb config element in the config xml file The following example shows a fully configured bdb config element Debug with Event Record and Playback 15 3 Configure a Component to Record Events lt bdb config gt lt db env path gt bdb lt db env path gt lt cache size gt 1000 lt cache size gt lt bdb config gt Table 15 1 lists the bdb config child elements Table 15 1 Child Elements of bdb config Child Element Description db env path Specifies the subdirectory in which OracleEvent Processing server creates the Berkeley DB instances relative to the config directory of your server Default bdb cache size Specifies the amount of memory in bytes available for Berkeley DB cache entries You can adjust the cache size to tune Berkeley database performance The cache size must be a power of 2 but it is otherwise limited only by available memory and performance considerations Default je maxMemoryPercent JVM maximum memory 4 Restart the Oracle Stream Explorer server 15 6 Configure a Component to Record Events You
336. rocessing its input streams for a finite period of time warm up window length time after which it generates the same stream of output events as other secondary servers running the application Configure the warm up window length time on a high availability output adapter Specify the length of the warm up window length time length in seconds or minutes For example if the application contains Oracle CQL queries with range based windows of 5 7 and 15 minutes then the minimum warm up window 17 14 Developing Applications for Event Processing with Oracle Stream Explorer Design Applications for High Availability length time is 15 minutes the maximum range based window size Oracle recommends that the maximum window length be padded with a few minutes to ensure that the necessary state is available So in the previous example 17 minutes or 20 minutes would be a good length for the warm up window length time The server uses system time during the warm up window length time period so the server time is not directly correlated with the application time associated with events being processed Type 1 applications must only be interested in events that occurred during a finite amount of time All range based Oracle CQL windows must be shorter than the warm up window length time and tuple based windows must be qualified by time For example the application should only query the last 10 events if they occurred within the last five min
337. roperty only relevant Java source shown public class MyEvent private String key public MyEvent public MyEvent String key this key key public String getKey return key public void setKey String key this key key The corresponding declaration in the assembly file looks like the following lt wlevs cache id myCache key properties key gt lt wlevs caching system ref caching system id gt lt wlevs cache gt 8 10 Developing Applications for Event Processing with Oracle Stream Explorer Configure a Cache as an Event Source 8 5 2 Metadata Annotation you can use the metadata annotation com bea wlevs ede api Key to annotate the event property in the Java class that implements the event type This annotation does not have any attributes To use a metadata annotation to specify a key 1 Import the com bea wlevs ede api Key package 2 Apply the Key annotation to a method The following example shows how to specify that the key property of the MyEvent event type is the key only relevant code is shown import com bea wlevs ede api Key public class MyEvent private String key public MyEvent public MyEvent String key this key key public String getKey return key Key public void setKey String key this key key 8 5 3 Composite Key You can use the key class attribute of the wlevs cache element to specify a composite key in which multiple properties form
338. rty name timeProperty value arrivalTime gt lt wlevs instance property name eventType value MyEventType gt lt wlevs adapter gt lt wlevs channel id inputChannel event type MyEventType gt lt wlevs source ref myHalnputAdapter gt lt wlevs application timestamped gt lt wlevs expression gt arrivalTime lt wlevs expression gt lt wlevs application timestamped gt lt wlevs channel gt Table 17 3 describes the additional child element Table 17 3 Child Elements of wlevs adapter for the High Availability Input Adapter Child Element Description wlevs instance Specify one or more instance property element name and property value attributes Table 17 4 lists the supported instance properties with their name and value attributes Table 17 4 High Availability Input Adapter Instance Properties Name Value timeProperty Specify the name of the event property to which the high availability input adapter assigns a time value This is the same property that you use in the wlevs application timestamped element of the downstream EPN component to which the high availability input adapter is connected keyProperties Specify a space delimited list of one or more event properties that the Oracle Stream Explorer high availability input adapter uses to identify event instances If you specify more than one event property you must specify a keyClass Default all event properties keyClass Specify the
339. rved as implied by the order of input events while order of output events across different partitions is not important to the consumer of the output events This relaxation provides some freedom to the CQL engine to process events across partitions in parallel when possible on multiple threads 6 12 Developing Applications for Event Processing with Oracle Stream Explorer Configure an Oracle CQL Processor for Parallel Query Execution Use the PARTITION_ORDERED value when you want to specify that events conforming to a given partition are processed serially but that order can be disregarded across partitions and events belonging to different partitions may be processed in parallel When using the PARTITION_ORDERED value you must also add the partition expression attribute to specify which expression for partitioning should be the basis for relaxing the cross partition ordering constraint In the following example the GROUP BY clause partitions the output based on symbol values The part ition expression attribute specifies that events in a given subset of events corresponding to a particular symbol value should be handled serially Across partitions on the other hand order can be disregarded lt query id myquery ordering constraint PARTITION_ORDERED partitioning expression symbol gt SELECT COUNT as c symbol FROM S RANGE 1 minute GROUP BY symbol lt query gt 6 6 3 Using partition order c
340. rvers The Spring context file supports caching configuration Listeners that are configured with a Spring context file receive events from the cache Data Related Components Table The Table component provides access to a relational database You configure the Table component with an ID event type and a data source to feed specific events into a relational database table Oracle Stream Explorer provides the Hadoop and NoSQLDB data cartridges for accessing big data storage Hadoop A data cartridge extension for an Oracle CQL processor to access large quantities of data in a Hadoop distributed file system HDFS HDFS is a non relational data store The Oracle CQL processor provides the Oracle CQL query code for the big data access You configure Hadoop with an ID event type the path to the database and the file separator character NoSQLDB A data cartridge extension for an Oracle CQL processor to access large quantities of data in an Oracle NoSQL Database The Oracle NoSQLDB Database stores data in key value pairs The Oracle CQL processor provides the Oracle CQL Introduction to Application Development 1 3 Streams and Relations query code for the big data access You configure NoSQLDB with an ID event type store name and store locations 1 3 Streams and Relations An Oracle Stream Explorer application handles events that arrive in a stream as raw event data The raw event data enters the EPN through an adapter that converts
341. s a sliding window of output events from the stream The size of the window is measured in milliseconds The Oracle Stream Explorer high availability buffering output adapter applies to simple failover and simple failover with buffering high availability quality of service options For more information see e Simple Failover e Simple Failover with Buffering e Configure the Buffering Output Adapter 17 5 3 Broadcast Output Adapter The Oracle Stream Explorer high availability broadcast output adapter implements a distributed queue trimming strategy The active primary instance broadcasts messages to the active secondary instances in the notification group telling them when to trim their local representation of the queue The Oracle Stream Explorer high availability broadcast output adapter applies to the light weight queue trimming high availability quality of service option For more information see e Light Weight Queue Trimming e Configure the Broadcast Output Adapter 17 5 4 Correlating Output Adapter The Oracle Stream Explorer high availability correlating output adapter correlates two event streams usually from JMS This adapter correlates an inbound buffer of events with a second source of the same event stream outputting the buffer if correlation fails after a configurable time interval Correlated events are trimmed from the queue Correlated events are assumed to be in order High Availability Applications 17 7 Hi
342. s and relations through low latency channels e A stream is a potentially infinite sequence of events where each event has its own time stamp In a stream the events must be ordered by time one after the other so that time stamps do not decrease from one event to the next There can be events in a stream that have the same time stamp e Ina relation sequence might be unimportant Instead events in a relation are related because they meet certain criteria For example events in a relation might be the result of a query executed against a stream of stock trades where the query looks for trade volumes above a particular level In a stream of stock trade events the events arrive in sequence and each event has its own time stamp To isolate the share price for trades that occurred within 5 seconds of one another configure an Oracle CQL processor to query the stream when it arrives from the channel with the following Oracle CQL code select price from StockTradeChannel range 5 seconds Because the query uses the range 5 seconds window to isolate the events the output of this query is a relation Although the events returned from the query have time stamps they are unordered in the relation Because the incoming events are ina stream the query executes continuously against every 5 seconds worth of events as they pass into the Oracle CQL processor As new events come along those meeting the query terms are inserted into the relation wh
343. s determined by JAXB By default the Java class name is the same as the name of the XML Schema complex type that describes the configuration data for the applicable stage See the Oracle Middleware my_oep oep xsd wlevs_application_config xsd schema for schema details See also Application and Resource Configuration Adapters Oracle Stream Explorer provides several packages that provide interfaces and classes for managing adapter behavior See Adapters Packages e com bea wlevs adapters httppubsub api package provides interfaces for converting inbound JavaScript Object Notation JSON messages to event types and back again To customize the way inbound and outbound JSON messages are converted to an event type and back to JSON format create a custom converter bean and use this API e com bea wlevs adapters httppubsub support package provides classes for establishing a connection to an HTTP publish subscribe server e com bea wlevs adapters jms api package provides interfaces for converting inbound JMS messages to event types and back again If you want to customize the way inbound and outbound JMS messages are converted to an event type and back create a custom converter bean and use this API e com bea wlevs ede api package provides interfaces for creating custom adapters See Oracle Fusion Middleware Customizing Oracle Stream Explorer Components Channels The com bea wlevs channel package provides an interface for implement
344. s gt lt low units gt 50 lt low units gt lt A cachestore scheme element that gets a store starts here gt lt cachestore scheme gt lt class scheme gt lt class factory name gt com bea wlevs cache coherence configuration SpringFactory lt class factory name gt lt method name gt getStore lt method name gt lt init params gt lt init param gt lt param type gt java lang String lt param type gt lt param value gt myCoherenceCache lt param value gt 8 6 Developing Applications for Event Processing with Oracle Stream Explorer Configure an Oracle Coherence Caching System and Cache lt init param gt lt init param gt lt param type gt java lang String lt param type gt lt param value gt cachel lt param value gt lt init param gt lt init params gt lt class scheme gt lt cachestore scheme gt lt The cachestore scheme element ends here gt lt local scheme gt lt caching schemes gt lt cache config gt tangosol coherence override xml File optional The tangosol coherence override xml file is a global per server file It contains what is referred to as the operational configuration in the Oracle Coherence documentation This file contains global server wide configuration settings for Oracle Coherence caching You create this file in an XML editor and put it in the Oracle Stream Explorer server config directory for the server you want to configure Note Do not include
345. s id lt wlevs event type repository gt lt wlevs event type type name HelloWorldEvent gt lt wlevs class gt com bea wlevs event example helloworld HelloWorldEvent lt wlevs class gt lt wlevs event type gt lt wlevs event type repository gt lt wlevs adapter id helloworldAdapter class com bea wlevs adapter example helloworld HelloWorldAdapter gt lt wlevs instance property name message value HelloWorld the current time is gt lt wlevs listener ref myHaInputAdapter gt lt wlevs adapter gt lt wlevs adapter id myHaInputAdapter provider ha inbound gt lt wlevs adapter gt lt wlevs channel id helloworldInputChannel event type HelloWorldEvent gt lt wlevs listener ref helloworldProcessor gt lt wlevs source ref myHaInputAdapter gt lt wlevs channel gt lt wlevs processor id helloworldProcessor gt lt wlevs channel id helloworldOutputChannel event type HelloWorldEvent advertise true gt lt wlevs listener gt lt bean class com bea wlevs example helloworld HelloWorldBean gt lt wlevs listener gt lt wlevs source ref helloworldProcessor gt lt wlevs channel gt 5 Configure your Oracle Stream Explorer application EPN assembly file to add an Oracle Stream Explorer high availability broadcast output adapter as shown e Addawlevs adapter element with provider set to ha broadcast after channel hel loworldOutputChannel e Update the wlevs listener element
346. s the EPN through the StockTradeCSV adapter on the left which handles data in the form of comma separated values CSV The StockTradeCSVadapter logic translates the incoming CSV data into Oracle Stream Explorer events The AdapterOutputChannel carries the newly generated events to the Oracle CQL processor Introduction to Application Development 1 1 Component Configuration The GetHighVolumeProcessor component queries the events as they stream through and selects stock trades that have a volume greater than 4000 The ProcessorOutputChannel component sends the selected events to the ListenerBean component which prints their stock symbol and volume information to the command line Se EPN Diagram Q Q 100 e Full EPN iMg 0 a2 m a 3 cmh a ProcessorOutputChannel EPN Diagram Event Types 1 1E AdapterOutputChannel StockTradeCSVAdapter GetHighVolumeProcessor ListenerBean Getting Started with Event Processing for Oracle Stream Explorer describes how to use Oracle JDeveloper to create Oracle Stream Explorer applications A walkthough of the TradeReport application and a fraud detection application are included 1 2 Component Configuration When you develop an Oracle Stream Explorer application you assemble and configure a network of components into an EPN Each component has a role in processing the data The following sections describe EPN components and their roles Events and Event Types An event type is a
347. s the localized version of the message to the display Make sure that the i18n_user properties file is in the Oracle Stream Explorer server class path Internationalization 12 7 Generate Localization Classes The weblogic il8ngen utility generates the il18n_user properties file that loads the message ID lookup hashtable weblogic i1l8n L10nLookup 12 8 Developing Applications for Event Processing with Oracle Stream Explorer Part Il Deploy Test and Debug Part II contains the following chapters e Assemble and Deploy e Testing 1 2 3 e Debug with Event Record and Playback 13 Assemble and Deploy To deploy and run an Oracle Stream Explorer application you assemble the application files into an OSGi bundle and deploy the OSGi bundle to a domain on an Oracle Stream Explorer server A deployed application processes client requests in the domain to which it is deployed You can assemble and deploy an application in Oracle JDeveloper with Oracle Stream Explorer Visualizer and manually This chapter explains how to assemble and deploy an application wrapped in an OSGi bundle manually See Using Visualizer for Oracle Stream Explorer for information about how to assemble and deploy and application and how to deploy and view an application library with Oracle Stream Explorer Visualizer This chapter includes the following sections e OSGi bundles e Application Dependencies e Application Libraries e Deployme
348. s the configured query to not consider event order for that query processing events in parallel where possible Oracle CQL Processors 6 11 Configure an Oracle CQL Processor for Parallel Query Execution 6 6 1 Set Up Parallel Query Execution Support While specifying support for parallel query execution is at its core a simple configuration task be sure to follow the other steps below so that you get the most out of the feature e Use the ordering constraint attribute to support parallel execution e Make sure you have enough threads calling into the processor to meet your performance goals The maximum amount of parallel query execution is constrained by the number of threads available to the CQL processor For example if an adapter upstream of the processor supports the number of threads you need and there is a channel between the adapter and the processor try configuring the channel with a max threads count of 0 so that it acts as a pass through If you don t want a pass through be sure to configure the query s upstream channel with a max threads value greater than 1 To make a max threads value setting useful you ll need to also set the max size attribute to a value greater than 0 For more information see Channels e Follow other guidelines related to setting the max threads attribute value For example to make a max threads value setting useful you ll need to also set the max size attribute to a value greater than
349. se in fidelity has a performance penalty 17 8 2 11 Plan for Server Recovery When a secondary server rejoins the multiserver domain the server needs time to rebuild the application state to match the current primary and active secondaries See Choose an Adequate warm up window length Time The time it takes for a secondary server to become available as an active secondary server after it rejoins the multiserver domain is a factor in the number of active secondary servers you require If a secondary is declared to be the new primary server before it is ready the secondary server throw an exception High Availability Applications 17 17 Design Applications for High Availability 17 8 3 Oracle CQL Query Restrictions In a high availability application Oracle CQL queries have the following restrictions For more information about Oracle CQL and the topics covered in this section see Oracle CQL Language Reference for Oracle Stream Explorer 17 8 3 1 Range Based Windows In a Type 1 application where the application must generate exactly the same sequence of output events as existing secondaries all range based Oracle CQL windows must be shorter than the warm up window length time See Choose an Adequate warm up window length Time Channels must use application time when Oracle CQL queries contain range based Windows See Prefer Application Time 17 8 3 2 Tuple Based Windows Ina Type 1 application where the application must
350. sed provider you must specify this element Berkeley DB Specifies the event types that are played back from the event store If this element is not specified then Oracle Stream Explorer plays back all event types Oracle RDBMS based provider You must specify this element Debug with Event Record and Playback 15 7 Configure a Component to Play Back Events Child Element Description time range Specifies the time period during which play back takes place with a start and end time Configure the time period with a start child element to specify a start time and an end child element to specify the end time Express the start and end time as XML Schema dat eTime values of the form yyyy mm ddThh mm ss For example to specify that play back to start on January 20 2010 at 5 00am and end on January 20 2010 at 6 00 pm enter the following lt time range gt lt start gt 2010 01 20T05 00 00 lt start gt lt end gt 2010 01 20T18 00 00 lt end gt lt time range gt For complete details of the XML Schema dateTime format see http www w3 org TR xmlschema 2 dateTime lexical representation If you do not specify a time period then no events are played back when the application is deployed and play back happens only after you explicitly start it using Oracle Stream Explorer Visualizer or wlevs Admin You can specify t ime range or time range of fset but not both 15 8 Developing Applications for E
351. serted into the cache If the channel sends a remove event an old event that exits the output window then the event is removed from the cache lt wlevs caching system id caching system id gt lt wlevs cache id cache id name alternative cache name gt lt wlevs caching system ref caching system id gt lt wlevs cache gt lt wlevs channel id tradeStream gt lt wlevs listener ref cache id gt lt wlevs channel gt 8 5 Index a Cache with a Key The following sections describe the options available to you to specify the key that is used to index the cache When you do not explicitly specify a key the event object serves as both the key and value when the event is inserted into the cache In this case the event class must include a valid implementation of the equals and hashcode methods that take into account the values of the key properties 8 5 1 Assembly File Specify a property name for the key property in the assembly file with the key properties attribute as shown in the following example lt wlevs cache id myCache key properties key property name gt lt wlevs caching system ref caching system id gt lt wlevs cache gt In this case all events that are inserted into the cache are required to have a property of this name at runtime otherwise Oracle Stream Explorer throws an exception For example assume the event type being inserted into the cache looks something like the following note the key p
352. settings For a complete reference see Schema Reference for Oracle Stream Explorer 5 2 1 Assembly File The assembly file shows the channel settings for the helloworldInputChannel The settings indicate that helloworldProcessor listens to the channel for events and that events flow into the channel from helloworld Adapter lt wlevs channel id helloworldInputChannel event type HelloWorldEvent gt lt wlevs listener ref helloworldProcessor gt lt wlevs source ref helloworldAdapter gt lt wlevs channel gt 5 2 Developing Applications for Event Processing with Oracle Stream Explorer Control Which Queries Output to a Downstream Channel To configure the channel as a relation add the is relation setting to the assembly file as follows lt wlevs channel id helloworldInputChannel event type HelloWorldEvent is relation true primary key myprimarykey gt If you make the channel a relation you must also configure the primary key attribute The primary key is a list of event property names separated by white space or a comma that uniquely identifies each event See wlevs metadata in Schema Reference for Oracle Stream Explorer for information about how to define a primary key To configure the channel to be application time stamped add the application timestamped and expression elements to the assembly file as follows When you set the is total order element to t rue the application time published is always stric
353. sing with Oracle Stream Explorer Partition an Incoming JMS Event Stream lt jndi provider url gt t3 ppurich pc 7001 lt jndi provider url gt lt destination jndi name gt Topicl lt destination jndi name gt lt session transacted gt true lt session transacted gt lt jms adapter gt lt jms adapter gt lt name gt JMS InboundAdapter2 lt name gt lt event type gt StockTick lt event type gt lt jndi provider url gt t3 ppurich pc 7001 lt jndi provider url gt lt destination jndi name gt Topic2 lt destination jndi name gt lt session transacted gt true lt session transacted gt lt jms adapter gt lt wlevs config gt Define a parameterized message selector in the jms adapter element for each JMS inbound adapter a Edit the component configuration file to add group binding child elements to the jms adapter element for the JMS inbound adapters b Add one group binding element for each possible JMS message selector value as shown lt jms adapter gt lt name gt JMS InboundAdapter lt name gt lt event type gt StockTick lt event type gt lt jndi provider url gt t3 ppurich pc 7001 lt jndi provider url gt lt destination jndi name gt Topicl lt destination jndi name gt lt session transacted gt true lt session transacted gt lt message selector gt CONDITION lt message selector gt lt bindings gt lt group binding group id ActiveActiveGroupBean_group1 gt lt param id CONDITION g
354. source in another bundle with a cache id of cacheprovider lt wlevs processor id myProcessor2 gt lt wlevs cache source ref cacheprovider cache id gt lt wlevs processor gt 8 4 Developing Applications for Event Processing with Oracle Stream Explorer Configure an Oracle Coherence Caching System and Cache Note When you have Oracle Coherence caches in the EPN assembly files of one or more applications deployed to the same Oracle Stream Explorer server never configure multiple instances of the same cache with a loader or a store You can inadvertently do this by employing multiple applications that each configure the same Oracle Coherence cache with a loader or store in their respective EPN assembly file If you configure multiple instances of the same cache with a loader or a store Oracle Stream Explorer throws an exception 8 2 2 Configuration File The coherence cache config xml file is the basic Oracle Coherence configuration file and must conform to the Oracle Coherence DTDs as is true for any Oracle Coherence application See the Oracle Coherence documentation for information about coherence cach config xml http docs oracle com middleware 1213 coherence index html An Oracle Stream Explorer Oracle Coherence factory must be declared when you use Spring to configure a loader or store for a cache You specify the factory with the cachestore scheme element and include a factory class that enables Oracl
355. ss the events in the caches with Oracle CQL and Java classes This chapter includes the following sections e Caching Defined e Configure an Oracle Coherence Caching System and Cache e Configure a Local Caching System and Cache e Configure a Cache as an Event Listener e Index a Cache with a Key e Configure a Cache as an Event Source e Configure a Cache with a Cache Listener e Configure a Third Party Caching System and Cache e Exchange Data Between a Cache and Another Data Source e Access a Cache from Application Code 8 1 Caching Defined A cache is a temporary storage area for event data To increase the availability of event data and to increase application performance you can create a cache so that applications can publish to or consume events from the cache An application can also access the processed event data written to the cache by other applications You can configure any stage in an Oracle Stream Explorer application that generates events to publish its events to the cache A cache does not have to be a stage in the EPN Another component or Spring bean can access events in the cache programmatically with the caching APIs A caching system is a configured instance of a caching implementation A caching system defines a named set of configured caches and the configuration for remote communication when any of the caches are distributed across multiple machines Oracle Stream Explorer caching enables an application to per
356. ssage catalogs to internationalize message text that your application sends to the server log or displays to the user The messages can provide information about anything occurring in the application such as which user invoked specific application components error conditions or help you debug an application before its release This chapter includes the following sections e Message Catalogs e Generate Localization Classes 12 1 Message Catalogs A message catalog is a single XML file that contains a collection of messages with each message indexed by a unique ID All internationalized text is externalized and defined in message catalogs and each message catalog defines a collection of log messages or simple text With message catalogs message strings can be converted to multiple locales without changing or recompiling the application code Message IDs are unique across all log message or locale message catalogs Within the message catalog file each localized version of the message is assigned a unique message ID and message text specific to the error Ideally a message is logged from only one location within the system so that a support team can easily find it Message IDs in simple text catalogs are unique within each simple text catalog There are the following three types of message catalogs e Log message catalogs Informational or error messages that your application logs to the server logs e Simple text message catalogs Simpl
357. ssos aaa a E E e E VE 5 3 5 3 Control Which Queries Output to a Downstream Channel ss ssssssssessssssrrisissesserresessesseee 5 3 5 4 Batch Processing Channels io iescseccussaiesceeves setgisecs na E e EE E EE 5 4 Bie Fault amin Ger cs sites pun aA E hates E E E A EET 5 4 5 6 EventPartitioner Channels zs 2222s 0ssececbdecsecoet f cid i E E a i 5 5 Bef Dismibuted FLOW Seiiunmie naa e iE E E a ees 5 5 5 7 1 Examples of Distributed Flows ssssssssssessssssssessessssnsrsisstsnesnsnsesresnesnensesnesnesnennesnenesnenness 5 6 5 7 2 Local Partitioning Channel iiisge tior epi kaire kE kaiaa i aaki arna aa pA Kpaka 5 6 Oracle CQL Processors 6 1 gt Processor Data SOUPCES etaria a a a a a 6 1 6 2 Assembly and Configuration Files c ccccccccesessesesesescesescsesceneesesesesnenesescececesescsnsnsnsneseseeneneneseees 6 2 6 3 QUES naaa ee a Misses a a e a e a era Sle td ARE 6 3 633 1 Stream Channels sunroso daner aa a tlh arena a a See 6 3 6 3 2 Time Based Relations WindOwS ccssssssssesseseeecsesecseseceeeeceeeececeaescsaesceaescsaesesaeeeareees 6 4 6 3 3 Processor Output Control Slides ccc eeeececesesssssesesesssesssesesesssssesessssssseeesseeseeeeeees 6 7 6 324 VIEWS nei aa a e eaea EERS a ss A A aa A eaaa Dee nisin wa nian aretha aie ein 6 8 64 COL Ag sree ations sicssticcieiiiinhelnnnddeitinda tiie a AEE ERK alien A E R 6 9 6 5 Configured Table Source mestyi g a aanere aeaa AEE KAKE E EE A
358. t Designate pid helloworldProcessor helloworldRule gt lt Object ocdref com oracle cep sample helloworld filter gt lt Designate gt lt MetaData gt Parameterized Applications 11 3 Where You Can Use Parameterized Applications 11 6 Where You Can Use Parameterized Applications You can use parameterized applications in the following three ways e Document an Application Channel Configuration e Oracle CQL Processor Query 11 6 1 Document an Application The following example documents the com oracle cep parameterizedapp application The pid attribute of the designate element corresponds to the Bundle SymbolicName in the MANIFEST MF lt OCD name Parameterized App Testing id com oracle cep parameterizedapp description The application is for parameterized app testing gt lt OCD gt lt Designate pid parameterizedapp gt lt Object ocdref com oracle cep parameterizedapp gt lt Designate gt 11 6 2 Channel Configuration The following example shows how to use an OCD with ADs to configure a channel The pid attribute of the designate element corresponds to the channel component in the EPN file lt OCD name Channel Configuration id com oracle cep channel description The channel definition in the OCEP Application ocep binding jmx EventChannel gt lt AD name Max Threads id maxThreads type Integer required true default 0 min 0 max 100 description Number of threads generati
359. t acctid lt 1000 lt param gt lt group binding gt lt group binding group id ActiveActiveGroupBean_group2 gt lt param id CONDITION gt acctid gt 1000 lt param gt lt group binding gt lt bindings gt lt jms adapter gt In this configuration when the application is deployed to an Oracle Stream Explorer server with a cluster element groups child element that contains ActiveActiveGroupBean_group1 then the CONDITION parameter is defined as acctid lt 1000 and the application processes events whose acctid property is less than or equal to 1000 Similarly when the application is deployed to an Oracle Stream Explorer server with a cluster element groups child element that contains Act iveAct iveGroupBean_group2 then the CONDITION parameter is defined as acctid gt 1000 and the application processes events whose acct id property is greater than 1000 Edit the component configuration file to configure a jms adapter element for the outbound JMS adapter as shown Configure the out bound JMS adapter with the same topic as the correlating in bound adapter in this example JMSInboundAdapter2 Topic2 and set session transacted to true lt xml version 1 0 encoding UTF 8 gt lt wlevs config xmlns wlevs http www bea com ns wlevs config application xmlns ha http www oracle com ns cep config cluster gt lt jms adapter gt lt name gt JMS InboundAdapter lt name gt lt event type gt StockTick lt event typ
360. t in the Oracle Middleware my_oep bin directory If want to bundle an application library for a new JDBC driver see Administering Oracle Stream Explorer 13 7 6 1 Command Location Syntax and Arguments You can find the bundler sh script in the Oracle Middleware my_oep bin directory The following shows the bundler sh command syntax Table 13 1 describes the command arguments bundler source JAR name NAME version VERSION factory CLASS service INTERFACE fragmenthost HOST stagedir PATH targetdir PATH import PACKAGE REGEX imods REGEX MODS import PACKAGE texport PACKAGE REGEX emods REGEX MODS dimport PACKAGE explode verbose Table 13 1 bundler sh Command Line Options Argument Description source JAR The path of the source JAR file to be bundled name NAME The symbolic name of the bundle The root of the target JAR file name is derived from the name value version VERSION The bundle version number All exported packages are qualified with a version attribute with this value The target JAR file name contains the version number factory CLASS An optional argument that specifies a space delimited list of one or more factory classes that are to be instantiated and registered as OSGi services Each service is registered with the OSGi service registry with name name and version version properties This argument is incompatible with the fragmenthost argument Assemble
361. t information from and write event information to an RMI connection The best way to create RMI adapters is through the Oracle JDeveloper components window The following assembly and configuration files generated by Oracle JDeveloper show the RMI inbound and outbound adapter configurations 4 22 Developing Applications for Event Processing with Oracle Stream Explorer RMI Adapters Note The RMI client connection cannot be closed See question F1 at http docs oracle com javase 8 docs technotes guides rmi fage neml Assembly File The inbound RMI adapter has a JNDI name to enable inbound clients to locate the EPN lt wlevs adapter id rmi inbound adapter provider rmi inbound gt lt wlevs instance property name jndiName value TradeReportApplication TradeReport rmi inbound adapter gt lt wlevs adapter gt lt wlevs adapter id rmi outbound adapter provider rmi outbound gt Configuration File The JNDI name enables the RMI outbound adapter to locate the output resource for the event data The JNDI provider enables directory service implementations to be plugged into the JNDI framework In this example the JNDI provider is the default Oracle WebLogic T3 client Oracle WebLogic T3 clients are Java RMI clients that use the Oracle T3 protocol to communicate with Oracle WebLogic Server T3 clients typically outperform other client types lt rmi adapter gt lt name gt rmi outbound adapter lt name gt lt
362. t sink can also initiate other processes in the same or in another application based on the event data Spring beans are managed by the Spring framework and are a good choice if you want to integrate your bean to an existing Spring deployment Event beans use Oracle Stream Explorer conventions for configuring beans so that they are managed by the Oracle Stream Explorer server With an event bean for example you get the support of Oracle Stream Explorer server features such as monitoring and event record and playback You can use event record and playback to debug an application Caching You can integrate a cache system with your Oracle Stream Explorer application to make a cache available as source or destination for data and event data that your application uses Integrating a cache can provide access to relatively static data at a speed that is suited to an application that handles streaming data A cache is a temporary storage area for events that you can create to improve the overall performance of your Oracle Stream Explorer application A cache is not necessary for the application to function correctly To increase the availability of the events and increase the performance of their applications Oracle Stream Explorer applications can publish to or consume events from a cache A caching system defines a named set of configured caches Oracle Stream Explorer distributes the configuration for remote cache communications across multiple se
363. t sources are pull data sources which means that Oracle Stream Explorer periodically polls the event source e You can join a stream only with a NOW window and only to a single database table Because changes in the table source are not coordinated in time with stream data you can only join the table source to an event stream with a Now window and you can only join to a single database table e With Oracle JDBC data cartridge you can integrate arbitrarily complex SQL queries and multiple tables and data sources with your Oracle CQL queries See Developing Applications with Oracle CQL Data Cartridges Note Oracle recommends the Oracle JDBC data cartridge for accessing relational database tables from an Oracle CQL statement Whether you use the NOW window or the data cartridge you must define data sources in the Oracle Stream Explorer server file as described in Administering Oracle Stream Explorer 6 5 1 Assembly File The following assembly file entry shows the setting for a table source with an id attribute of Stock lt wlevs table id Stock event type TradeEvent data source StockDataSource gt Oracle Stream Explorer uses the event type and the data source to map a relational table row to the event type The TradeEvent event type is created from a Java class that has the following five private fields that map to columns in the relational database symbol price lastPrice percChange and volume Note
364. t that joins cache data source s e Ifthe cache is a processor source you connect the cache directly to the channel on the EPN e Ifthe cache is a processor sink it can be connected directly to a processor Access a Cache from an Oracle CQL Statement This procedure assumes that you have already configured the caching system and caches For more information see e Configure a Local Caching System and Cache e Configure an Oracle Coherence Caching System and Cache Configure a Third Party Caching System and Cache 1 If you have not already done so create the event type that corresponds to the cache data and register it in the event repository See Events and Event Types 2 Specify the key properties for the data in the cache 3 In the EPN assembly file update the configuration of the cache to declare the event type of its values use the value type attribute of the wlevs cache element For example lt wlevs caching system id caching system id gt lt wlevs cache id cache id name alternative cache name value type CompanyEvent gt lt wlevs caching system ref caching system id gt lt wlevs cache gt The value type attribute specifies the type for the values contained in the cache This must be a valid type name in the event type repository This attribute is required only if the cache is referenced in an Oracle CQL query This is because the query processor needs to know the type of events in the cache
365. t the number of words the application maps incoming sentences into meaningful terms and then reduces these terms to a count per term With stream processing you can count a real time flow of words such as the one coming stream from Twitter However if it is done through stream processing handling such a high volume of words becomes an issue The distributed processing subscribes to disparate parallel twitter streams and converges the results number of words Smart Meter Energy Consumption It is common for households today to collect their energy consumption through the use of smart meters located in their premises Typically these smart meters output energy consumption sensor data in the form of events periodically through out the day e g every 1 minute This sensor data is captured by downstream management systems in regional processing centres and is used to calculate useful descriptive statistics such as the average energy consumption of a house or neighborhood and how it relates to historical data for the region These running aggregations can be partitioned to efficiently calculate the energy consumption A distributed flow can be used to identify outliers for example households that are above or below the general consumption and to predict future consumption This data can be used to control the buying and selling process of energy with their partners Risk Analysis Distributed flow can be used for real time calculation of
366. t when a server rejoins the cluster your application accesses the same cache or table as before The application must join to the same external relation again The data source defined on the server must not have been changed to ensure that you are pulling data from same data source 17 8 2 7 Source Event Identity Externally Many high availability solutions require that events be correlated between different servers To correlate events the events must be universally identifiable The best way to make event universally identifiable is use external information preferably a time stamp to seed the event For more information see Prefer Application Time 17 8 2 8 Understand the Importance of Event Ordering Primary and secondary servers must generate the same output events and in exactly the same order when you choose high availability quality of service options that use queue trimming and equality based event identify non monotonic event identifiers that do not increase continually Generating output events in different orders can cause missed output events or unnecessary duplicate output events when a failure occurs Consider the output event streams shown in Figure 17 8 The primary server has output events a b and c After outputting event c the primary sends the secondary a queue trimming message Figure 17 8 Event Order Output Event Stream t Primary f e d c b a Trim Secondary f c d e b a The secondary server t
367. t work manager gt Jett yWorkManager lt work manager gt lt concurrent consumers gt 1 lt concurrent consumers gt lt session transacted gt true lt session transacted gt High Availability Applications 17 33 Configure High Availability Adapters lt jms adapter gt lt jms adapter gt lt name gt JMSOutboundAdapter lt name gt lt event type gt JMSEvent lt event type gt lt jndi provider url gt t3 localhost 7001 lt jndi provider url gt lt destination jndi name gt Topic2 lt destination jndi name gt lt delivery mode gt nonpersistent lt delivery mode gt lt session transacted gt true lt session transacted gt lt jms adapter gt lt wlevs config gt 14 Optionally configure the component configuration file to include the Oracle Stream Explorer high availability input adapter and correlating output adapter as shown lt ha ha inbound adapter gt lt name gt myHaInputAdapter lt name gt lt ha ha inbound adapter gt lt ha ha correlating adapter gt lt name gt myHaBroadcastAdapter lt name gt lt fail over delay gt 2000 lt fail over delay gt lt ha ha correlating adapter gt 15 Optionally add an Act iveAct iveGroupBean to your EPN to improve scalability For more information see Partition an Incoming JMS Event Stream 16 Oracle Stream Explorer automatically selects one of the Oracle Stream Explorer servers as the primary 17 10 Configure High Availability Adapters You configure Oracle St
368. tChannel event type HelloWorldEvent gt lt wlevs listener ref helloworldProcessor gt lt wlevs source ref helloworldAdapter gt lt wlevs channel gt lt wlevs processor id helloworldProcessor gt lt wlevs channel id helloworldOutputChannel event type HelloWorldEvent advertise true gt lt wlevs listener gt lt bean class com bea wlevs example helloworld HelloWorldBean gt lt wlevs listener gt lt wlevs source ref helloworldProcessor gt lt wlevs channel gt lt beans gt 2 2 1 Nested Stages in an EPN Assembly File When you define a child stage within a parent stage in an EPN the child stage is said to be nested Only the parent stage can specify the child stage as a listener The following example shows the EPN assembly source in which Hel loWorldBean is nested within the he 1 loworldOutputChannel Only the parent helloworldOutputChannel may specify the nested bean as a listener lt wlevs adapter id helloworldAdapter class com bea wlevs adapter example helloworld HelloWorldAdapter gt lt wlevs instance property name message value HelloWorld the current time is gt lt wlevs adapter gt lt wlevs channel id helloworldInputChannel event type HelloWorldEvent gt lt wlevs listener ref helloworldProcessor gt lt wlevs source ref helloworldAdapter gt lt wlevs channel gt lt wlevs processor id helloworldProcessor gt lt wlevs channel id helloworldOutput
369. talOrder value false gt lt wlevs adapter gt This example shows a broadcast output adapter configuration where the mandatory key is based on more than one event property properties timeProperty and account ID key values are monotonic they do increase continually and total order unique lt wlevs adapter id myHaSlidingWindowAdapter provider ha broadcast gt lt wlevs listener gt lt bean class com bea wlevs example helloworld HelloWorldBean gt lt wlevs listener gt lt wlevs instance property name keyClass value com acme MyCompoundKeyClass gt lt wlevs instance property name monotonic value true gt lt wlevs instance property name totalOrder value true gt lt wlevs adapter gt A compound key Java class com acme MyCompoundKeyClass is mandatory and its implementation is shown in the following example The hashCode and equals methods are required When you specify a keyClass the keyProperties instance property is ignored Oracle Stream Explorer assumes that the compound key is based on all the getter methods in the keyClass package com acme public class MyCompoundKeyClass private int timeProperty private int accountID High Availability Applications 17 27 Configure High Availability Quality of Service 9 10 11 public MyCompoundKeyClass public int getTimeProperty return orderID public setTimeProperty int timeProperty this timeProperty timeProperty
370. tatement lt query id helloworldRule gt lt CDATA select age from eventChannel now gt lt query gt Events and Event Types 3 13 Access the Event Type Repository 3 10 Access the Event Type Repository The Oracle Stream Explorer event type repository keeps track of the event types defined for your application When you create an event type in Oracle JDeveloper it becomes available to the Oracle Stream Explorer application In some cases you might need to write code that explicitly accesses the repository For example when your event type is created as a tuple Java logic that accesses instance of the type will need to first retrieve the type definition using the repository API then use the API to access the instance property values The Event TypeRepository is a singleton OSGi service Because it is a singleton you only need to specify its interface name to identify it You can get a service from OSGi in any of the following ways e EPN Assembly File e Spring DM ServiceReference Annotation e Oracle Stream Explorer Service Annotation For more information see Java API Reference for Oracle Stream Explorer 3 10 1 EPN Assembly File You can access the Event TypeRepository by specifying an osgi reference in the EPN assembly file lt osgi reference id etr interface com bea wlevs ede api EventTypeRepository gt lt bean id outputBean class com acme MyBean gt lt property name eventT
371. te anew channel with a Java class event type Testing 1 2 3 14 15 EPN Command Interface e EventChannel createChannel String channelName Map lt String String gt metadata Create a new system timestamped channel with a metadata based event type e EventChannel createChannel boolean relation String applicationTimestampProp boolean totalOrder List lt String gt keys String channelName Map lt String String gt metadata Create anew channel with a metadata based event type e EventChannel createChannel boolean relation String applicationTimestampProp boolean totalOrder List lt String gt keys String channelName Map lt String String gt metadata EventBuilder Factory factory Create anew channel with a metadata based event type Processor getProcessors Returns all Oracle CQL processors created in the current session Processor createProcessor Creates an Oracle CQL processor in the current session StreamSource link StreamSource fromStage StreamSink toStage Connects a stage to stage void unlink StreamSource source StreamSink sink Disconnects the source from the sink Statement createView Processor processor String id String StatementValue Creates an Oracle CQL view Statement createQuery Processor processor String id String statement Value Creates an Oracle CQL query Object createEvent String eventTypeName Creates
372. tems in a way that would cause conflicts when multiple copies of the application run concurrently The application sends output events to an external downstream system Multiple instances of the application can connect to the downstream system simultaneously although only one instance of the application can send messages at any one time Within these constraints the following different cases are of interest The application is allowed to skip sending some output events to the downstream system when there is a failure Duplicates are also allowed Use the Simple Failover high availability quality of service option The application is allowed to send duplicate events to the downstream system but must not skip any events when there is a failure Use the Simple Failover with Buffering and Light Weight Queue Trimming high availability quality of service options The application must send exactly the same stream of messages events to the downstream system when there is a failure modulo a brief pause during which events may not be sent when there is a failure Use the Precise Recovery with JMS high availability quality of service option 17 8 2 High Availability Design Patterns When designing your Oracle Stream Explorer application for use with Oracle Stream Explorer high availability options observe the following design patterns Select the Minimum High Availability Your Application can Tolerate Use High Availability Components at All
373. ter as shown lt processor gt lt name gt helloworldProcessor lt name gt lt rules gt lt query id helloworldRule gt lt CDATA select from helloworldInputChannel Now gt lt query gt lt rules gt lt processor gt lt ha ha buffering adapter gt lt name gt myHaSlidingWindowAdapter lt name gt lt window length gt 0 lt window length gt lt ha ha buffering adapter gt 8 Deploy your application to the deployment group you created in step 1 Oracle Stream Explorer automatically selects one of the Oracle Stream Explorer servers as the primary 17 9 2 Configure Simple Failover With Buffering You configure simple failover using the Oracle Stream Explorer buffering output adapter with a sliding window size greater than zero 0 This procedure starts with the example EPN that Figure 17 10 shows and adds the required components to configure it for simple failover with buffering Figure 17 10 Simple Failover With Buffering EPN B helloworldInputChannel 2 helloworldOutputChannel 2 helloworldAdapter helloworldProcessor HelloWorldBean Configure simple failover with buffering 1 Create a multiserver domain using Oracle Coherence For more information see Administering Oracle Stream Explorer 2 Create an Oracle Stream Explorer application 3 Edit the MANIFEST MF file to add the following Import Package entries e com bea wlevs ede api cluster e com oracle cep cluster hagroups e com oracle cep cluste
374. the quality of service option that suits your application s tolerance for missed and duplicate events and expected event throughput Note that primary and secondary server hardware requirements increase as the quality of service becomes more precise Table 17 1 Oracle Stream Explorer High Availability Quality of Service High Availability Option Missed Duplicate Performanc Events Events e Overhead Simple Failover Yes Yes few Negligible many Simple Failover with Buffering Yes few Yes Low many Light Weight Queue Trimming No Yes few Low Medium Precise Recovery with JMS No No High 17 7 1 Simple Failover The simple failover high availability quality of service is characterized by the lowest performance overhead fastest recovery time and the least data integrity both missed events and duplicate events are possible during failover The primary server outputs events and secondary servers discard their output events because they do not buffer output events If the current active primary fails anew active primary is chosen and begins sending output events once it is notified During failover many events can be missed or duplicated by the new primary depending on whether it is running ahead of or behind the old primary respectively During the failover window events can be missed For example if you process 100 events per second and failover takes 10 seconds then you miss 1000 events The new primary server enters
375. the raw event data into an event An event is an ordered set of values tuple Events are similar to a table row in a relational database in that an event has a schema The event schema defines the properties and types for each event value Events are unlike a table row in a database in that a table row contains static data In a stream of events when an event arrives including which event arrives before or after another event can make a difference Your application needs to be able to account for time and sequence For example in an application that processes stock trades events made up of stock symbol price last price percentage change and volume information would arrive one after the other in the order in which each trade was executed Your application logic might look for trades of one stock that occurred immediately after trades of another In an event processing application the sequence in which events occur in a stream is as important as the data types and values of each event property Oracle Stream Explorer programming conventions reflect the importance of time and sequence Your code needs to discover which events are related to one another based on certain criteria such as a shared stock symbol Your code also needs to discover sequence patterns such as trades within fifteen seconds of one another To account for both the sequential and relational aspects of event data Oracle Stream Explorer implements the concepts of stream
376. the PRIMARY state immediately There is no configurable readiness threshold that must be met before the new primary server transitions out of the BECOMING_PRIMARY state When an Oracle Event Processing server rejoins the multiserver domain it is immediately available as a secondary High Availability Applications 17 9 Choose a Quality of Service Option To implement this high availability quality of service you configure your EPN with a high availability buffering output adapter with a sliding window of size zero before each output adapter To reduce performance overhead rather than use a high availability input adapter use application time with some incoming event property For more information see Configure a Simple Failover 17 7 2 Simple Failover with Buffering The simple failover with buffering high availability quality of service is characterized by a low performance overhead faster recovery time and increased data integrity no missed events but many duplicate events are possible during failover The primary server outputs events and the secondary servers buffer their output events If the current active primary fails a new active primary is chosen and begins sending output events once it is notified During the failover window events might be missed For example if you are processing 100 events per second and failover takes 10 seconds then you miss 1000 events If the secondary buffers are large a significant nu
377. the appropriate method to pass in events received from the upstream stage connected to your class For more information about event batching see Batch Processing Channels For complete API reference information about the Oracle Stream Explorer APIs described in this section see the Java API Reference for Oracle Stream Explorer 7 3 Event Source Interfaces You can create a Java class that sends events to a downstream stage in an event processing network You can create an event source for example to send events your Java code has created or altered from event data flowing through the EPN A Java class that is an event source implements one of the interfaces described in this section Each of these interfaces provides a method used by the Oracle Stream Explorer server to pass into your class an instance of a sender class The sender instance your event source receives implements one of the sender interfaces described in this section The sender interfaces provide methods your code can call to send events as streams or relations and batched or unbatched to the downstream EPN stage that follows such as a channel The interfaces described here support sending events either as streams or relations Interfaces for relation also support sending events as streams Table 7 2 Interfaces for Implementing an Event Source Interface Description com bea wlevs ede api StreamSou Implement this interface to send events as a rce stream At runtim
378. the channel listener Note When you implement custom partitioning and parallel processing make sure to add code to preserve event order and to carefully manage multithreading Figure 18 4 shows an EPN that uses an event partitioner to partition a channel In this example the inbound adapter sends events of type PriceEvent which has two properties stock symbol and stock price The example partitions the channel on the symbol property and shows you how to add multithreading to the channel or to the upstream adapter 18 12 Developing Applications for Event Processing with Oracle Stream Explorer Custom Channel Event Partitioner Figure 18 4 Event Partitioner EPN aa processor1 e lt _2a gt _B EventPartitionerChannel channel inbound processor2 outbound processor3 18 4 2 Implement the EventPartitioner Interface 1 2 3 In Oracle JDeveloper open your Oracle Stream Explorer application Edit your MANIFEST MF file to import package com bea wlevs channel Select the project and select File gt New gt From Gallery The New Gallery dialog displays In the New Gallery dialog select General in the left panel and Java Class in the right panel and click OK The Create Java Class dialog displays In the Create Java Class dialog provide a class name package name and extends information Under Optional Attributes and Implements use the Add button to locate the
379. the events You enable the playback of events for a component by updating its configuration file and adding the playback parameters element Using the child elements of playback parameters you specify the event store from which the events are played back the list of event types you want to play back by default all are played back the time range of the recorded events you want to play back and so on By default Oracle Stream Explorer plays back the events in a time accurate manner However you can configure that the events get played back either faster or slower than they originally flowed out of the component from which they were recorded After you deploy the application and events start flowing through the network you must start the playback with Oracle Stream Explorer Visualizer or wlevs Admin Oracle Stream Explorer reads the events from the persistent store and inserts them into the appropriate place in the EPN When a component receives a playback event the playback event looks exactly like the original event If a downstream component is configured to record events then Oracle Stream Explorer records the arriving playback events and real time events For more information see e Using Visualizer for Oracle Stream Explorer e Administering Oracle Stream Explorer 15 5 Configure Berkeley DB You can use the default Berkeley DB configuration as is You only need to make configuration changes to customize the location of the Be
380. the tangosol coherence override xml file when you use Oracle Coherence for clustering Add the following XML to the Oracle Coherence configuration file to reference the tangosol coherence override xml file Include the cluster name element to prevent Oracle Coherence from attempting to join existing Oracle Coherence clusters when Oracle Stream Explorer starts up This can cause problems and sometimes prevent Oracle Stream Explorer from starting lt coherence xml override tangosol coherence override xml gt lt cluster config gt lt member identity gt lt cluster name gt com bea wlevs example provider lt cluster name gt lt member identity gt lt coherence gt For more information about Oracle Stream Explorer clusters see Administering Oracle Stream Explorer 8 2 3 Cache Loader Bean The com oracle cep cacheloader package provides the CsvCacheLoader class for loading CSV events into a Coherence cache You use a cache loader with an inbound adapter by replacing the sourceUr1 property The first assembly file CSV adapter configuration shows a CSV inbound adapter that loads a file with the sourceUrl property The second assembly file CSV adapter entry shows a CSV inbound adapter that loads a cache loader bean Cached Event Data 8 7 Configure a Local Caching System and Cache Load Events in a CSV file lt wlevs adapter id StockTradeCSVInboundAdapter provider csv inbound gt lt wlevs listener ref AdapterOutputC
381. the window expires the query will be incorrect The following example shows an invalid Oracle CQL query that joins a Range window against a cache If the cache changes before this window expires the query will be incorrect Consequently this query will raise Oracle Stream Explorer server error external relation must be joined with s now SELECT trade symbol trade price trade numberOfShares company name FROM TradeStream Range 8 hours as trade CompanyCache as company WHERE trade symbol company id When you use data from a cache in an Oracle CQL query Oracle Stream Explorer pulls the data rather than it being pushed as is the case with a channel This means that continuing with the query executes only when a channel pushes a t rade event to the query the stock symbol data in the cache never causes a query to execute it is only pulled by the query when needed e You must specify the key property needed to do a lookup based on the cache key Consider two streams S and C with schemas id group value where the cache key is id A valid query is select count as n from S now C where S id C id e Joins must be executed only by referencing the cache key e You cannot use a cache in a view Instead use a join 8 18 Developing Applications for Event Processing with Oracle Stream Explorer Access a Cache from Application Code e Only a single channel source may occur in the FROM clause of an Oracle CQL statemen
382. thout the xm1 extension is used to generate runtime class and property names choose the name carefully Follow these guidelines for naming message catalogs e Do not choose a message catalog name that conflicts with the names of existing classes in the target package for which you are creating the message catalog e Choose message catalogs names that contain only characters that are allowed in class names e Follow class naming standards For example the resulting class names for a catalog named Xyz xml are XyzLogLocalizer and XyzLogger The following considerations also apply to message catalog files e Log message IDs are generally six character strings with leading zeros Some interfaces also support integer representations e Simple text catalogs message IDS can consist of any string value 12 2 Developing Applications for Event Processing with Oracle Stream Explorer Message Catalogs e Java lets you group classes into a collection called a package Oracle recommends that a package name be consistent with the name of the subsystem in which a particular catalog resides Consistent naming makes OSGi imports easier to define e The log Localizer classes are actually ResourceBundle property files 12 1 3 Message Arguments The message body message detail cause and action sections of a log message can include message arguments as described by java text MessageFormat Make sure your message content conforms to the
383. time on the primary Oracle Stream Explorer server begin processing events from input streams at that point and generate valid output events The input stream is not paused while the application starts and input events are constantly being generated and arriving You can assume that in many cases a secondary stage that does the same thing but at a slightly different time also produces output events that are valid from the point of view of the application although not necessarily identical to those events produced by the primary server because of slight timing differences For example a financial application that only runs while the market is open might operate as a Type 2 application as follows All servers can be brought up before the market opens and begin processing incoming events at the same point in the market data stream Multiple secondary servers can be run to protect against failure and if the number of secondary servers is sufficient while the market is open then do not restart High Availability Applications 17 15 Design Applications for High Availability secondary servers that fail or add additional secondary servers because no secondary server needs to recover its state 17 8 2 6 Ensure Applications are Idempotent You scan run two copies of an application on different servers and the copies do not conflict in a shared cache or database If you use an external relation such as a cache or table then you must ensure tha
384. timestamped gt lt wlevs expression gt inboundTime lt wlevs expression gt lt wlevs application timestamped gt lt wlevs channel gt 8 Configure the Oracle Stream Explorer high availability correlating output adapter failOverDelay The following example shows a correlating output adapter configuration where the failOverDelay is 2000 milliseconds lt wlevs adapter id myHaCorrelatingAdapter provider ha correlating gt lt wlevs listener ref JMSOutboundAdapter gt lt wlevs instance property name failOverDelay value 2000 gt lt wlevs adapter gt 9 Create a second regular JMS input adapter The following example shows a JMS adapter named JMSInboundAdapter2 lt wlevs adapter id JMSInboundAdapter2 provider jms inbound gt lt wlevs adapter gt The following JMS input adapter must be configured identically to the first JMS input adapter in this example JMS InboundAdapter The following example shows the component configuration file for both the JMS input adapters Note that both have exactly the same configuration including the same provider lt jms adapter gt lt name gt JMS InboundAdapter lt name gt lt jndi provider url gt t3 localhost 7001 lt jndi provider url gt lt destination jndi name gt Topicl lt destination jndi name gt lt user gt weblogic lt user gt lt password gt weblogic lt password gt lt work manager gt Jett yWorkManager lt work manager gt lt concurrent consumers gt
385. tition order capacity value or max threads value or if the max threads value is set to 0 meaning it s a pass through channel When using partition order capacity keep in mind the following e The partition order capacity value is only useful when you re setting the ordering constraint attribute to PARTITION_ORDERED e Increasing partition order capacity generally increases parallelism and scaling For example if your profiling reveals lock contention bottlenecks you might find it helpful to increase partition order capacity to see if contention is reduced e Setting partition order capacity even higher than the number of available threads can be helpful in some cases because of the particular way partitioning is done in the CQL processor e There is some resource cost in memory used by specifying very high values e Tuning this parameter is very dependent on details of the application and the input rate Tuning by experimentation may be necessary to determine an optimal value 6 6 4 Limitations Think of parallel query execution as a performance enhancement feature that you specify support for so that the CQL processor can use it whenever possible Not all queries can be executed in parallel This includes queries using certain COL language features For example if your query uses some form of aggregation such as to find the maximum value from a range of values the CQL processor may not be able to fully execut
386. tly greater than the last value used lt wlevs application timestamped is total order true gt lt wlevs expression gt mytimet10 lt wlevs expression gt lt wlevs application timestamped gt 5 2 2 Configuration File The configuration file shows the channel configuration settings The settings customize the channel to buffer process events asynchronously max size to use a maximum of 4 threads max threads and to use a heartbeat time out of 10000 nanoseconds heartbeat lt channel gt lt name gt helloworldInputChannel lt name gt lt max size gt 10000 lt max size gt lt max threads gt 4 lt max threads gt lt heartbeat gt 10000 lt name gt lt channel gt 5 3 Control Which Queries Output to a Downstream Channel If you configure an Oracle CQL processor with more than one query then by default all queries send their results to the downstream channel You can control which queries send their results to the downstream channel with the selector element Figure 5 1 shows an EPN with channel fi1lteredSt ream connected to the upstream Oracle CQL processor filteredFanoutProcessor Figure 5 1 EPN With Oracle CQL Processor and Downstream Channel D igs priceStream filteredStream PriceAdapter filterFanoutProcessor The following example shows the queries configured for the Oracle CQL processor lt processor gt lt name gt filterFanoutProcessor lt name gt lt rules gt lt query id Yr3Sector gt
387. tore that is bundled with the Oracle Stream Explorer server Berkeley DB is a fast scalable transactional database with industrial grade reliability and availability For more information about Berkeley DB see http www oracle com technetwork database database technologies berkeleydb overview index html When you deploy an application that is configured to use the record and playback feature the Oracle Stream Explorer server creates the database schema and an instance of Berkeley DB in the following directory Oracle Middleware my_oep user_projects domains domainname servername bdb Note The database key is the record time plus the sequence number You can use the default Berkeley database configuration as is You only need to make configuration changes to customize the location of the Berkeley database instance or to tune performance See Configure Berkeley DB for information about how to configure Berkeley DB You can use the event store API to query a store for past events given a record time range and the component from which the events were recorded The actual query you use depends on the event repository provider for example you would use Oracle CQL for the default persistent event store provider included with Oracle Stream Explorer You can also use these APIs to delete old events from the event store 15 3 Record Events You can configure recording for any component in the EPN that produces events such as processors
388. tory gt To create and register a java util Map event type First identify the event data that the event type carries and then decide the properties the event type requires e To register declaratively edit the EPN assembly file using the wlevs event type repository element wlevs event type child element as shown lt wlevs event type repository gt lt wlevs event type type name AnotherEvent gt lt wlevs properties type map gt lt wlevs property name name value java lang String gt lt wlevs property name age value java lang Integer gt lt wlevs property name address value java lang String gt lt wlevs properties gt lt wlevs event type gt lt wlevs event type repository gt At runtime Oracle Stream Explorer generates a bean instance of the AnotherEvent class for you The AnotherEvent class has three properties name age and address e To register programmatically use the Event TypeRepository class as shown EventTypeRepository rep getEventTypeRepository java util Map map new Map name java lang String age java lang Integer address java lang String rep registerEventType AnotherEvent map Usages public void onInsertEvent Object event throws EventRejectedException java util Map anEvent java util Map event System out println Age anEvent get age The following Oracle CQL rule shows how you can reference the MarketEvent ina SELECT s
389. tream Explorer Design Constraints Data Type Description Benefits and Limitations Tuple A structure that you create and register declaratively in the EPN assembly file For more information see Create and Register a Tuple Event Type Benefits Requires no Java programming to create the event type An event type is created by declaring it in the EPN assembly file Useful for quick prototyping Limitations Using instances of this type in Java application logic requires programmatically accessing the event type repository to get the instance s property values A tuple is also unlikely to be useful when integrating the Oracle Stream Explorer with other systems java uti 1 Map Based on an instance of java util Map You don t implement or extend the Map interface Rather you specify that the interface should be used when configuring the event type in the EPN assembly file If you write Java code to access the type instance you treat it as a Map instance For more information see Create and Register a Map Event Type Benefits Requires no Java programming to create the type An event type is created by declaring it in the EPN assembly file Useful for quick prototyping Limitations Does not perform as well as other types 3 3 Design Constraints Keep in mind the following CSV adapter and database table constraints when you design event types CSV Adapter Constraints When you declarati
390. tream regardless of whether events were deleted or updated RSTREAM SELECT FROM StockTradeIStreamChannel ROWS 3 SLIDE 2 The following configuration file entry uses an RSTREAM to batch by numbers lt processor gt lt rules gt lt query id rule2 lt CDATA RSTREAM SELECT FROM StockTradeIStreamChannel ROWS 3 SLIDE 2 gt lt query gt lt rules gt lt processor gt Batch by Time Window Gl With a time window Oracle Stream Explorer batches events by a time interval RANGI operator When you specify the time interval Oracle COL sends the events to the output stream at a time that is a multiple of the number you specified For example if you specify 5 seconds the events are sent at 5 10 15 20 and so on seconds In the case where the first event arrives at 1 2 or 3 seconds into the interval the first output will be smaller than the others The following example specifies a range of 5 minutes with a slide every 30 seconds SELECT FROM StockTradeIStream RANGE 5 MIN SLIDE 30 SECONDS The following configuration file entry shows a time based slide lt processor gt lt rules gt lt query id rule2 lt CDATA RSTREAM SELECT FROM StockTradeIStreamChannel RANGE 5 MIN 30 SECONDS gt lt query gt lt rules gt lt processor gt Views enable you to create an Oracle CQL statement that can be reused by other Oracle CQL queries A view element contains Oracle CQL subquery statements The view
391. tting to deploy to an Oracle WebLogic Server container Bundle ManifestVersion 2 This is because Oracle Stream Explorer uses Felix in the Oracle WebLogic Server container Manifest Version 1 0 Bundle ManifestVersion 2 Bundle Version 1 0 0 Bundle Vendor Oracle Corporation Bundle Copyright Copyright c 2006 2009 by Oracle Export Package com bea wlevs event example helloworld version 12 1 2 com bea wlevs example helloworld version 12 1 2 Import Package com bea wlevs configuration version 12 1 2 com bea wlevs ede api version 12 1 2 com bea wlevs ede impl version 12 1 2 com bea wlevs ede spi version 12 1 2 com bea wlevs ede version 12 1 2 com bea wlevs management spi version 12 1 2 com bea wlevs spring support version 12 1 2 com bea wlevs spring version 12 1 2 com bea wlevs util version 12 1 2 org apache commons logging version 1 1 0 org springframework beans factory config version 2 5 6 org springframework beans factory version 2 5 6 org springframework beans version 2 5 6 org springframework core annotation version 2 5 6 org springframework osgi context version 1 2 0 org springframework osgi extensions annotation version 1 2 0 org springframework osgi service version 1 2 0 org springframework util version 2 5 6 Bundle Name example helloworld 13 8 Developing Applications for Event Processing with Oracle Stream Explorer Assemble an OSGi Bundle with bundle
392. ty name name type char gt lt lt wlevs property name age type int gt lt lt wlevs property name birthplace type char gt lt wlevs properties gt lt wlevs event type gt lt wlevs event type repository gt This event type corresponds to the data feed file shown in Create the Data Feed File To configure the csvgen adapter that receives this data use the following wlevs adapter element lt wlevs adapter id csvgenAdapter provider csvgen gt lt wlevs instance property name port value 9001 gt lt wlevs instance property name eventTypeName value PersonType gt lt wlevs instance property name eventPropertyNames value name age birthplace gt lt wlevs adapter gt Note how the bold values in the adapter configuration example correspond to the PersonType event type registration If you use the wlevs class element to specify your own JavaBean when registering the event type then the event PropertyNames value corresponds to the JavaBean properties For example if your JavaBean has a get Name method then one of the properties of your JavaBean is name For more information on event types see Events and Event Types 14 2 Event Inspector Service Use the Event Inspector service to test and debug Oracle CQL queries during development With the Event Inspector service you can view trace the events that flow out of any EPN stage and inject events into any EPN stage The Event Inspector service uses
393. types described in Design Constraints With a tuple based event type your Java code must always set and get its property values with the Event TypeRepository APIs Note The order in which the EPN processes tuples with the same time stamp is not guaranteed when the EPN is made up of multiple streams Data Types When you specify the tuple event type properties declaratively in the application assembly file you can use any of the native Oracle CQL data types in the property type The following XML shows the use of different types in the application assembly file 3 10 Developing Applications for Event Processing with Oracle Stream Explorer Create and Register a Tuple Event Type lt wlevs event type repository gt lt wlevs event type type name SimpleEvent gt lt wlevs properties gt lt wlevs property name id type char length 1000 gt lt wlevs property name msg type char gt lt wlevs property name count type double gt lt wlevs property name time_stamp type timestamp gt lt wlevs properties gt lt wlevs event type gt elses event type repository gt Procedures e Create a Tuple Event Type in the Assembly File e Usea Tuple Event Type in Java Code e Usea Tuple Event Type Instance in Oracle CQL Code 3 8 1 Create a Tuple Event Type in the Assembly File Register your event type declaratively in the Oracle Stream Explorer event type repository with the wlevs event type repository e
394. ue2 lt destination jndi name gt lt user gt weblogic lt user gt lt password gt welcomel lt password gt lt session transacted gt true lt session transacted gt lt delivery mode gt nonpersistent lt delivery mode gt lt jms adapter gt 4 11 JMS Custom Message Converter Bean To customize the conversion between JMS messages and event types create inbound and outbound converter beans and package them with your Oracle Stream Explorer Application 4 14 Developing Applications for Event Processing with Oracle Stream Explorer JMS Custom Message Converter Bean 4 11 1 Implement Interfaces The inbound and outbound converter beans implement methods in the following two inbound and outbound interfaces See the Java API Reference for Oracle Stream Explorer for a full description of these APIs e Inbound com bea wlevs adapters jms api InboundMessageConverter You have to implement its convert method The return value is a List of events to be passed downstream public List convert Message message throws MessageConverterException JMSException message parameter Corresponds to the incoming JMS message e Outbound com bea wlevs adapters jms api OutboundMessageConverter interface You have to implement its convert method The return value is a List of JMS messages public List lt Message gt convert Session session Object event throws MessageConverterException JMSException session parameter The javax jms Sessi
395. uery by using the CQL processor s MBean interface 6 16 Developing Applications for Event Processing with Oracle Stream Explorer Fault Handling Note When you update an Oracle CQL query with an MBean do not send events during the update procedure If you send events during some queries the order of the events in the output stream is not guaranteed For example when you update an Oracle COL query from unordered to ordered in an Oracle CQL parallelism execution In the following example the code provides a high level illustration of handling a fault package com example faulthandler import com bea wlevs ede api FaultHandler public class SimpleFaultHandler implements FaultHandler private String suppress Called by the server to pass in fault information Override public void handleFault Throwable fault String catchers throws Throwable Log the fault return 6 7 2 Register a Fault Handler After you have written a fault handling class you can associate it with an EPN stage by registering it as an OSGi service The simplest way to do this is to register the handler declaratively in the EPN assembly file Note Due to inherent OSGi behavior runtime fault handler registration from your configuration happens asynchronously meaning that a small amount of warm up time might be required before the handler can receive faults To be sure your handler is ready for the first events that enters the netwo
396. ught or reaches a stage that cannot catch it such as a processor or multithreaded channel that does not have an associated fault handler Note that if you rethrow an exception any channels in the catcher s list must have an associated fault handler to catch the exception The EventProcessingException instance could also be one of the exception types that extend that class including CQLExecutionException Arithmet icExecutionException and others See the Java API Reference for Oracle Stream Explorer The EventProcessingException instance provides methods with which your code can retrieve insert delete and update events that were involved in generating the fault Your implementation of the method should do one of the following e Consume the fault in the way that a Java try and catch statement might If your implementation does not rethrow the fault then event processing continues with subsequent events However query processing continues with its state reset as if the query had been restarted The processing state is lost and processing begins fresh with events that follow those that provoked the fault e Rethrow the fault so that it is received by upstream stages or their fault handlers As when the fault is consumed queries continue processing events although the query state is reset with subsequent events The upstream stage receiving the fault always has the option of explicitly stopping the offending q
397. ume Stock FROM StockTraceIStreamChannel Now Stock WHERE StockTradeIStreamChannel symbol Stock symbol Because changes in the table source are not coordinated in time with stream data you can only join the table source to an event stream with a Now window and you can only join to a single database table 6 6 Configure an Oracle CQL Processor for Parallel Query Execution For improved performance you can enable a CQL query to execute in parallel rather than serially as it does by default When the CQL code supports it you can configure a query so that it can process incoming events in parallel when multiple threads are available to the CQL processor You should enable parallel query execution only in cases where the relative order of the query output events is unimportant to the query s downstream client For example event ordering probably is not important if your query is intended primarily to filter events such as to deliver to clients a set of stock transactions involving a particular company where the transaction sequence is irrelevant By default without enabling parallel execution queries process events from a channel serially For events routed through a channel that uses a system time stamp event order is the order in which events are received through a channel that is time stamped by an application event order is the order determined by a time stamp value included in the event Relaxing the total order constraint allow
398. und gt lt wlevs instance property name converterBean ref myConverter gt lt wlevs adapter gt 4 12 Oracle Business Rules Adapter The Oracle Business Rules OBR adapter is an event bean that wraps the business rules engine from the Oracle Business Rules product The OBR adapter lets you assert and retract events as facts to trigger business rules You can configure OBR rules to generate events and add business logic to an Oracle COL processor downstream to process the events For example you can invoke St reamSender sendInsertEvent within the rules file to send data out of an OBR adapter as an event Oracle JDeveloper does not provide a drag and drop component for the assembly file or the EPN diagram but it does provide a drag and drop component for the configuration file You can create an OBR adapter by adding entries to the assembly file and by dragging and dropping the OBR adapter into the configuration file For more information about creating OBR adapters by adding entries see the OBR documentation at http www oracle com technetwork middleware business rules documentation index html Assembly File The event type repository element specifies the event type repository for the application In the following example the repository has a single event type named HelloWorldEvent and is implemented by the Hel loWorldEvent java class The next adapter specifies an id equal to he loworldAdapter ID with a v
399. utes Applications that do not have this property cannot be Type 1 applications and cannot use the warm up window length period For example an application that uses an tuple based partitioned window that has no time qualification cannot use the warm up window length period because an arbitrary amount of time is required to rebuild the state of the window If a Type 1 application uses the high availability broadcast output adapter it can trim events with a unique application specific key or a monotonic key like application time Trimming events with application time is encouraged because it is more robust and less susceptible to bugs in the application that can cause an output event to not be generated For more information see e Oracle CQL Query Restrictions e Buffering Output Adapter e Broadcast Output Adapter e Correlating Output Adapter 17 8 2 5 2 Type 2 Applications A Type 2 application does not require the new secondary server to generate the same sequence of output events as existing secondary servers once it fully joins the high availability deployment and notification groups It simply requires that the new cluster member generate valid output events with respect to the point in time at which it begins processing input events A Type 2 application does not require a warm up window length period Most applications are Type 2 applications It is common for an application to be brought up at an arbitrary point in
400. vailability Design Patterns ccccsescscetesceceseseeceneesesesesneneseececeneseessnanenens 17 13 18 17 8 3 Oracle COL Query Restrictions ccccccceccsseeseseseensnesesesesensesesesesesesesesesereeneeees 17 18 17 9 Configure High Availability Quality of Service ceccessesesesesenssesesesesensneeseseenseseeeees 17 19 17 9 1 Configure a Simple Failover c cccccsecessccsssesesesescsesnesesescsesssesesescsessseseseseseseseseseee 17 19 17 9 2 Configure Simple Failover With Buffering ccccccsssesesnsteseseeneteseececesesesesnenenens 17 21 17 9 3 Configure Light Weight Queue Trimming ccccccccccseensneeseseeneeseececesesesesnenenens 17 23 17 9 4 Configure Precise Recovery With JMS ccccccsecccscesescsssneneeseseeneesescecesesesesnaenens 17 28 17 10 Configure High Availability Adapters 0 0 cccccceesesesssssssesessscssssesesesssenseseseseseesesess 17 34 17 10 1 Configure the High Availability Input Adapter cscs ereneeesees 17 34 17 10 2 Configure the Buffering Output Adapter s ssssssrsssssssissestsrtessessesteseessesnenteneeseess 17 36 17 10 3 Configure the Broadcast Output Adapter cccccecseseccsssssesesescenseeseseseeesenees 17 38 17 10 4 Configure the Correlating Output Adapter s sssssssssssssssesisrtessissesiesressnsneseeneesness 17 39 Scalable Applications 18 1 Default Channel Scalability Settings ccc ceccsssssesesescsesseesescsesesesescsesesesesessseseeseseeces 18 1 18 1 1
401. value constraints as described in Table 3 3 Table 3 3 EPN Assembly File event type Element Property Attributes Attribute Description name The name of the table column you want to access as specified in the SQL create table statement You do not need to specify all columns type The Oracle Stream Explorer Java type from Table 3 4 that corresponds to the column s SQL data type length The column size as specified in the SQL create table statement When you specify the properties of an event type for use with a relational database table you must observe the additional JDBC type restrictions listed in Table 3 4 When you join a stream with the Derby database where the join condition compares two timestamp values one value is from the stream attribute and the other value is from the Derby data source attribute the Derby database performs the predicate evaluation However the Derby database supports only the yyyy MM dd HH mm ss nnnnnn format For the Derby database to perform the evaluation correctly the stream timestamp value must use the Derby database format Table 3 4 SQL Column Types and Oracle Stream Explorer Type Equivalents SQL Type Oracle Stream com bea wlevs ede api T Description Explorer Java Type ype ARRAY Ljava lang Objec Array of depth 1 of java lang Object BIGINT java math BigInte bigint An instance of ger java math BigInteger BINARY byte Array of depth 1 of byte BIT java lang Bo
402. vely specify the properties of an event type for use with CSV adapters you can only use the data types that Table 3 2 describes Table 3 2 CSV Adapter Types Type Usage char int float long double Single or multiple character values Use for both char and java lang String values Optionally you may use the length attribute to specify the maximum length of the char value for the property with name id The default length is 256 characters If you need more than 256 characters you should specify an adequate length Numeric values in the range that java lang Integer specifies Numeric values in the range that java lang Float specifies Numeric values in the range that java Lang Long specifies Numeric values in the range that java lang Double specifies For more information see Events and Event Types 3 3 Design Constraints e Testing 1 2 3 Database Table Constraints You can use a relational database table as a source of event data binding data from the table to your event type instance at runtime When your event data source is a database table you must follow the guidelines represented by the following tables When an event type will receive data from a database table a property configured for the type will each receive data from a particular column in the database When configuring the event type note that its property child elements have attributes that have particular meanings and
403. vent Processing with Oracle Stream Explorer Configure a Component to Play Back Events Child Element Description time range offset playback speed repeat max size Specifies the time period during which play back takes place with a start time and a duration Configure the time period with a start child element to specify a start time and a duration child element to specify the length of time to play back events Express the start time as an XML Schema dat eTime value of the form yyyy mm ddThh mm ss Express the duration in the form hh mm ss For example to specify that play back should start on January 20 2010 at 5 00am and continue for 3 hours enter the following lt time range offset gt lt start gt 2010 01 20T05 00 00 lt start gt lt duration gt 03 00 00 lt duration gt lt time range offset gt For complete details of the XML Schema dat eTime format see http www w3 org TR xmlschema 2 dateTime lexical representation If you do not specify a time period then no events are played back when the application is deployed and playback happens after you explicitly start it using Oracle Stream Explorer Visualizer or wlevs Admin You can specify t ime range or time range of fset but not both Specifies the playback speed as a positive float The default value is 1 which corresponds to normal speed A value of 2 means that events are played back 2 times faster than the original r
404. vers Or if your application monitors trends and patterns related to stock market trades events contain event data that corresponds to stock trades Event data can arrive at an application in many forms By creating an event type to represent the data inside the application you create a predictable way for application logic to work with the data Events carry event data through the event processing network EPN When you design the event type keep in mind how you plan to access process and manipulate the event data in your code Events and Event Types 3 1 Choose a Data Structure for the Event Type 3 2 Choose a Data Structure for the Event Type An event type can get its structure from a JavaBean class a tuple ora java util Map class Oracle recommends that you use JavaBean classes to structure event types JavaBeans provide greater flexibility within your application and simplify integration with existing systems JavaBean event types are flexible For example you assign a JavaBean event type to a property of a tuple or java util Map event type The following code shows the event type Student that defines its address property as the JavaBean event type Address lt wlevs event type repository gt lt wlevs event type type name Student gt lt wlevs properties gt lt wlevs property name name type char gt lt wlevs property name address type classpackage Address gt lt wlevs properties gt lt wlevs event typ
405. vior is specific to a naming scope Some naming scopes resolve names by simple matching Other scopes resolve names by mapping the name used to do the lookup into a new name Once a name is mapped lookup proceeds recursively beginning with the current scope 2 10 Developing Applications for Event Processing with Oracle Stream Explorer 3 Events and Event Types An event type is a data structure that defines the data contained in an event When raw event data comes into the Oracle Stream Explorer application the application binds that data to an event of a particular event type In your application you define the event type in terms of its data set and the corresponding data types This chapter includes the following sections e How Events Function e Choose a Data Structure for the Event Type e Design Constraints e Event Type Repository e Properties e Interval and Time Stamp Properties e Create and Register a JavaBean Event Type e Create and Register a Tuple Event Type e Create and Register a Map Event Type e Access the Event Type Repository e Share Event Types Between Application Bundles e Control Event Type Instantiation with an Event Type Builder Class 3 1 How Events Function An event is structured data that relates to something that happens or is happening For example if your application reacts to changes to a cluster of servers events capture snapshot data that is collected by the device that monitors the ser
406. vs event type repository gt lt wlevs adapter id helloworldAdapter class com bea wlevs adapter example helloworld HelloWorldAdapter gt lt wlevs instance property name message value HelloWorld The time is gt lt wlevs adapter gt lt wlevs channel id helloworldInputChannel event type HelloWorldEvent gt lt wlevs listener ref helloworldProcessor gt lt wlevs source ref helloworldAdapter gt lt wlevs channel gt lt wlevs processor id helloworldProcessor gt lt wlevs channel id helloworldOutputChannel event type HelloWorldEvent advertise true max threads 0 max size 0 gt lt wlevs listener ref OBRAdapter gt lt wlevs source ref helloworldProcessor gt lt wlevs channel gt lt wlevs adapter id OBRAdapter provider obr gt lt wlevs instance property name decisionFunction value handleri gt lt wlevs instance property name dictionaryUrl value file helloworld rules gt lt wlevs listener ref OutputBean gt lt wlevs adapter gt lt wlevs event bean id OutputBean class com bea wlevs example helloworld HelloWorldBean gt lt wlevs event bean gt Configuration File The configuration file declares the Oracle CQL processor and query rules to use to process the HelloworldEvent received from the OBR adapter It also provides the OBR adapter handler handler1 for accessing the OBR rules The dictionary url element specifies the path to the OBR dictionary fil
407. wlevs cache gt lt bean id orderFunction class orderFunction impl class gt lt wlevs property name cache ref cache id gt lt bean gt In the example the ref attribute of the wlevs property element references the id value of the wlevs cache element Oracle Event Processing automatically injects the cache implemented as a java util Map into the user defined function In the user defined function s Java source add a setMap Map method with the code that implements whatever you want the function to do with the cache package com bea wlevs example import java util Map public class OrderFunction public void setMap Map map For more information on user defined functions see Oracle Fusion Middleware Oracle CQL Language Reference for Oracle Event Processing 8 22 Developing Applications for Event Processing with Oracle Stream Explorer Access a Cache from Application Code 8 10 5 Access a Cache with JMX At runtime you can access a cache programmatically using JMX and the MBeans that Oracle Stream Explorer deploys for the caching systems and caches you define For more information see Administering Oracle Stream Explorer 8 10 5 1 How to Access a Cache With JMX Using Oracle Stream Explorer Visualizer The simplest and least error prone way to access a caching system or cache with JMX is to use the Oracle Stream Explorer Visualizer For more information see Using Visualizer for Oracle Stream Explorer
408. wlevs util Service Service annotation to specify a component method that is injected with an OSGi service reference You typically add this annotation to JavaBean setter methods where needed The Service annotation has the following attributes 1 12 Developing Applications for Event Processing with Oracle Stream Explorer OSGi Service Platform Table 1 1 Attributes of the com bea wlevs util Service JWS Annotation Tag Name Description Data Required Type serviceBeanName The name of the bean that backs the injected String No service Can be null cardinality Valid values for this attribute are enum No e ServiceCardinality CcoO__1 e ServiceCardinality CcO__N e ServiceCardinality Cl__1l e ServiceCardinality Cl__N Default value is ServiceCardinality Cl__l contextClassloa Valid values for this attribute are enum No der e ServiceClassloader CLIENT e ServiceClassloader SERVICE_PROV IDER e ServiceClassloader UNMANAGED Default value is ServiceClassloader CLIENT timeout Timeout for service resolution in milliseconds int No Default value is 30000 serviceType Interface or class of the service to be injected Class No Default value is Service class filter Specifies the filter used to narrow service String No matches Value may be null The following example shows how to use the Service annotation For another example see Access the Event Type Repository Service
409. xml transform stream oracle jdbc version 1 1 0 0_11 2 0 2 0 ora cle sql version 1 1 0 0_11 2 0 2 0 org apache commons logging versi on 1 1 0 org springframework beans version 2 5 6 org springframew ork beans factory version 2 5 6 org springframework beans factory c onfig version 2 5 6 org springframework core annotation version 2 5 6 org springframework ejb config org springframework osgi context version 1 2 0 org springframework osgi extensions annotation versio n 1 2 0 org springframework osgi service version 1 2 0 org spring framework util version 2 5 6 org xml sax org xml sax ext weblogic j dbc extensions version 1 10 0 0 weblogic xml stax version 1 10 0 0 6 Add the following lines of code to your application to invoke the web service EchoService service new EchoService EchoPort port service getEchoServicePort String echo port echo foo 10 3 Expose an Application as a Web Service In this example the application is the web service provider To Expose an Application as a Web Service 1 Create or obtain the WSDL for the web service 10 2 Developing Applications for Event Processing with Oracle Stream Explorer Expose an Application as a Web Service This example uses a WSDL named EchoService WSDL 2 Implement the service Consider using the java jws annotations WebService and WebMethod 3 Adda bea jaxws xml file to your application bundle Table 10 1 descri
410. xplorer Event Sink Interfaces You implement the Bat chSt reamSink interface if you expect your class to receive batched events as a stream The interface has a single method onInsertEvents which the Oracle Stream Explorer server calls to pass in a collection of events received from the upstream stage The Bat chSt reamSink interface extends St reamSink so can receive unbatched events also For more information about event batching see Batch Processing Channels Example 7 1 Implement the StreamSink Interface public class TradeListener implements StreamSink public void onInsertEvent Object event throws EventRejectedException if event instanceof TradeEvent String symbolProp TradeEvent event getSymbol Integer volumeProp TradeEvent event getVolume Code to do something with the property values 7 2 2 Implement RelationSink A class that receives events as a relation can receive any of the kinds of events possible in a relation which are insert events delete events and update events Unlike a stream events in a relation are unordered and include events that have been updated or deleted by code that created or operated on the relation As a result the interfaces that support receiving events as a relation have methods through which your class can receive insert delete or update events You implement the Relat ionSink interface if your class receives unbatched events as a relation The Relat ionS
411. xplorer provides the bundler sh UNIX shell script that you can use to manually assemble an OSGi bundle that provides services and packages to other bundles For example you can deploy a JDBC driver in an OSGi bundle JAR file to make it available to other OSGi applications For more information see Administering Oracle Stream Explorer Note There is no Windows support no bundler cmd The bundle sh shell script reads the source JAR files and creates a target JAR file that includes the content of the source JAR files and a MANIFEST MF file with the appropriate bundle related entries specified All Java packages found in the source archive are exported to the target bundle With bundler sh you can also generate a bundle activator A bundler activator instantiates one or more classes in the JAR file and registers each instantiated object as an OSGi service This feature enables component bundles to access and manipulate multiple versions of specific factory classes during execution The procedure to manually assembly an OSGi bundle consists of the following steps e Prepare and Organize the Files e Create the MANIFEST MF File e Include Third Party JAR Files Reference Foreign Stages e Assemble an OSGi Bundle that Activates Note See the HelloWorld example source directory for a sample build xml Ant file that performs many of the steps described below The build xml file is located in Oracle Middleware my_oep oep exa
412. xport l l Application A gt Application B gt Application C t In this example Application A depends on Application B Application B depends on Application C and Application C depends on Application A Application C declares and exports the MarketEvent class Applications A and B import the MarketEvent 13 10 Developing Applications for Event Processing with Oracle Stream Explorer Assemble an OSGi Bundle with bundle sh class that Application C provides In this example the MANIFEST MF files of the OSGi bundles A and B should contain Require Bundle C Note the following e When you redeploy a foreign stage you must redeploy all foreign stages that depend on that application or foreign stage For example if you redeploy Application B you must redeploy Application A e If there is a class path dependency between one foreign stage and another when you deploy the foreign stage that declares and exports the shared class you must redeploy all foreign stages that import the shared class For example if you redeploy Application C you must also redeploy Application A and B because Application A and B have a class path dependency on Application C MarketEvent 13 7 6 Assemble an OSGi Bundle that Activates Once you prepare and organize the files you can use the bundle sh shell script to assemble the files into an OSGi bundle and define the activator classes You can find the bundle sh scrip
413. y cache provider then you must use the CachingSystem interface If you want to perform operations on a cache that are not part of the java util Map interface then you can use the Cache interface If you create cache listeners loaders or stores for an Oracle Stream Explorer local cache then the beans you write must implement the CacheListener CacheLoader or CacheStore interfaces If you create cache listeners loaders or stores for an Oracle Coherence cache then the beans you write must implement the appropriate Oracle Coherence interfaces If you create cache listeners loaders or stores for a third party cache then the beans you write must implement the appropriate third party cache interfaces 8 10 1 Access a Cache from an Oracle CQL Statement You can reference a cache from an Oracle CQL statement in much the same way you reference an event source such as a channel this feature enables you to enrich standard streaming data with data from a separate source The code in the following example shows a valid Oracle CQL query that joins trade events from a standard channel named s1 with stock symbol data from a cache named stockCache You must abide by these restrictions when using a cache in an Oracle CQL query e Whenever you query a cache you must join against the Now window This guarantees that the query will execute against a snapshot of the cache If you join against any other window type then if the cache changes before
414. y_oep examples source applications recplay For details about running and building the example see Getting Started with Event Processing for Oracle Stream Explorer This chapter includes the following sections e Event Flow e Berkeley DB e Record Events e Play Back Events e Configure Berkeley DB e Configure a Component to Record Events e Configure a Component to Play Back Events e Start and Stop the Record and Playback of Events 15 1 Event Flow The following graphic shows the EPN of the event record and playback example to demonstrate where you can record events and where you can play events back The simpleEvent Source adapter is configured to record events The recording happens as events flow out of the adapter The event St ream channel is configured to play back events The playback happens where events flow into the channel Debug with Event Record and Playback 15 1 Berkeley DB Figure 15 1 Configuring Record and Playback in an EPN y B eventStream coal simpleEventSource x playbackHttpPublisher sadapter gt channel gt sname gt simpleEventSources name gt snamereventStream name gt srecord parameters gt lt playback parameters gt lt record parameters gt siplayback parameters gt Adapter Channel Processor sJadapter gt lt channel gt 15 2 Berkeley DB When you record events by default the Oracle Stream Explorer server stores them in Berkeley DB which is a persistent event s
415. ype e Create a named channel with a Java class event type e Create a channel with a Java class event type e Create a named relation channel with update keys and a map based event type epn channels Lists all channels within the EPN scope pn createevent Creates an event of the provided event type epn end Ends the EPN session pn eventtypes Lists all event types epn heartbeat Sends a heartbeat to channel that is time stamped by an application epn query Registers an Oracle CQL query epn remove Removes all statements that are registered within the EPN scope epn send Sends an insert event to a named channel Same as the sendinsert command pn senddelete Deletes a named event in a named channel epn sendinsert Sends an insert event to a named channel Same as the send command epn sendupdate Updates an OSGi bundle with the bundle at the provided URL epn statements Lists all registered Oracle CQL statements within the EPN scope epn subscribe Subscribe to an event channel and output events to a file epn unsubscribe Unsubscribe from an event channel epn view Register an Oracle CQL view 14 3 6 Management Commands The management commands are shown and described in the following list mngt deployapp Deploys an application with optional parameters mngt deployrepapp Deploys an application from the respository mngt introspect Introspects an application for its public interfaces
416. ypeRepository ref etr gt lt bean gt Then in the MyBean class you can access the Event TypeRepository using the event TypeRepository property initialized by Spring package com acme import com bea wlevs ede api EventTypeRepository import com bea wlevs ede api EventType public class MyBean private EventTypeRepository eventTypeRepository public void setEventTypeRepository EventTypeRepository eventTypeRepository this eventTypeRepository eventTypeRepository public void onInsertEvent Object event throws EventRejectedException get the event type for the current event instance EventType eventType eventTypeRepository getEventType event Throw com bea wlevs ede api EventRejectedException to have an exception propagated up to senders Other errors will be logged and dropped 3 14 Developing Applications for Event Processing with Oracle Stream Explorer Share Event Types Between Application Bundles 3 10 2 Spring DM ServiceReference Annotation You can access the Event TypeRepository by using the Spring DM ServiceReference annotation to initialize a property in your Java source import org springframework osgi extensions annotation ServiceReference import com bea wlevs ede api EventTypeRepository ServiceReference setEventTypeRepository EventTypeRepository etr 3 10 3 Oracle Stream Explorer Service Annotation You can access the Event TypeRepository with the Oracl

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