PADRES User Guide
Contents
1. volume gt 0 at BrokerC demo stockquote startSQsubscriber sh is the script that starts this automated stock quote subscriber ADD ClientY 142 150 237 136 demo bin stockquote startSQsubscriber sh i ClientY s class eq STOCK volume gt 0 b socket 10 0 1 3 10002 BrokerC To deploy this topology using PANDA run panda with the topology file assume it is named topology txt Note You must configure PANDA before using it See Section 6 2 on Configuring PANDA startpanda topology txt Alternatively you may load the topology file after running panda without the command line parameter by using the load command in panda s console gt is startpanda load topology txt Loading a topology file does not automatically start the broker client processes Once the topology file successfully loaded and panda has verified that all nodes referenced by the file is reachable issue the deploy command to deploy the processes startpanda topology txt Checking reachability of referenced nodes in topology file 10 10 10 10 10 01I OK 0 1 2 OK Osle OK 0 1 4 OK 20 1 5 OK topology txt successfully loaded 13 Type help or for help gt deploy After issuing the deploy command PANDA will ask if you want to skip PANDA s automated 2 phase deployment process By skipping the 2 phase deployment process you will be given a prompt to decide whether or not to proceed with phase 22. Configure tarball package Essentially the tarball is the complete PADRES package with 3rd party library jar files PANDA will download the tarball onto the remote nodes and extract the tarball in the HOME directory not SPADRES_HOME Therefore it is recommended that a directory containing the contents of PADRES be automatically created upon extraction Note that the remote padres path property value mentioned above should match this To enable uploading of the PADRES tarball onto the remote nodes you should configure the line below in panda properties to point to the URL of your tarball PANDA uses wget for this operation and therefore the URL should be a valid HTTP address that is prefixed with http scripts env TARBALL lt url to tarball gt 6 3 PANDA Commands You may enter any one of the commands below into the Deployer s console help This screen exit quit bye ciao cu Exits the simulator hnttp www ece uci edu chou ssh key html 14 load lt file gt Loads the topology input workload file Checks to see if all nodes in the topology file are reachable by automatically running the sshtest command sshtest lt IP address list gt Returns the list of node IP addresses that it can and cannot reach via SSH You will need to provide the absolute path i e path that starts with like home padres iplist txt Results are stored in build panda lt date gt log sshtest ok failed log The followi
3. cli Available values ON OFF Default value OFF Heartbeat Whether to exchange heartbeat messages periodically between neighbors In configuration file padres heartbeat Command line option h Available values ON OFF Default value OFF Web Management Interface Whether to enable a management interface to the broker In configuration file padres managementinterfac Command line option m Available values ON OFF Default value OFF Web Management Interface Configuration Specifies property file to be used to setup the properties of the management interface In configuration file padres mipropertyfile Command line option mf Available values a file pathname Default value etc mi properties Broker Info Messages To turn on the auto publication of BrokerInfo messages Even if it is OFF PADRES monitor can still force a broker to publish BrokerInfo messages In configuration file padres monitor brokerinfo Command line option mon bi Available values ON or OFF Default value OFF Broker Info Details To control the amount of details conveyed in BrokerInfo messages In configuration file padres monitor advsubinfo Command line option mon bi advsubinfo Available values FULL to include full list of advs subs or COUNT just to include the counts of advs subs Default value FULL The configuration options are set in the following order with later options overwriting earlier ones e Default values hard coded in t
4. The amount of time the client sleeps between the above retries In configuration file connection retry pauseTime Command line option pause Available values An integer Default value 1 Client States Enabling this option will make the client to store all previously disseminated pub sub adv This option can quickly use a lot memory and should only be used for testing purposes In configuration file client store_detail_state Command line option state Available values ON OFF Default value ON for interactive clients e g GUIClient OFF otherwise Periodicity of Logging The time between two logging events In configuration file log period Command line option None Available values An integer Default value 60 5 3 The startclient Command This is a script to start a PADRES client By default it starts GUIClient but this script can be used to invoke other clients such as the CLIClient as explained at the begining of this section See Section 5 2 for the available options when starting a client It can also accept JVM specific options like Xms and Xmx One other option available for this start script is the host lt hostname gt option You might have to use this if the following two cases are applied to your client 1 The client is connecting to a broker that is accepting connections via the RMI communication proto col 11 2 The client is instantiated on a host machine that has more than one network interface ether
5. Table 1 PADRES system parameters When launching a PADRES system the broker overlay has to be created before instantiating the clients The broker overlay can be created using the following commands startbroker uri socket localhost 1100 BrokerA n socket localhost 1101 BrokerB startbroker uri socket localhost 1101 BrokerB startbroker uri socket localhost 1102 BrokerC n socket localhost 1101 BrokerB Notes Option uri is used to specify the URI of the broker and option n is to specify the neighbors A broker URI must have the format of lt comm_protocol gt lt hostname gt lt port gt lt broker_id gt The comm_protocol can be either rmi or socket hostname can be the DNS name or the IP address of the machine where the broker is instantiated port is the port number where the broker is listening at for incoming connections and broker_id is the unique identifier of the broker Only one broker can listen at a particular port of a host Broker ID must be unique and should not contain the hyphen character The neighbors are given in a comma separated with no space list of broker URIs When two brokers are connected in the overlay it is enough to specify the relation only at one side in the above example only BrokerA and BrokerC use the n option There is no stipulated order in which the brokers have to be started Brokers will detect whether the specified neighbors are alive by periodi
6. deployment Alternatively if you choose not to skip the 2 phase deployment process PANDA will automatically deploy phase 2 once it sees that all brokers and links are established in phase 1 using an internal monitoring client To stop the deployment at any time use the stop command Ignore any innocuous error messages The full list of PANDA commands syntax and descriptions can be found in Section 6 2 Configuring PANDA By default all of PANDA s configuration is contained in SPADRES_HOME etc panda panda properties You may use c config_file_path command line argument of the startpanda command to load your own configuration file for PANDA Configure remote login name This is the login name used to log into all of the remote nodes scripts env SLICE lt login name gt Configure remote S PADRES_HOME This is a relative path to the remote machines home s directory remote padres path lt path to padres home directory gt Configure SSH keys Panda uses public private ssh keys to log into remote nodes See herd or google yourself on how to generate public private ssh keys Note that PANDA requires you to use an empty paraphrase Put the public key in HOME ssh directory at all remote nodes Then modify the line illustrated below in panda properties to reflect the path to your private key Note the private key must only have read and write permission only to the user scripts env IDENTITY lt path to private ssh key gt
7. 1979 B1 n socket 10 0 1 1 lt time s gt ADD lt id gt lt nodeIPAddr gt startSQpublisher sh i lt id gt s lt symbol1 gt lt symbol12 gt r lt ratel gt lt rate2 gt b lt broker_uri gt d lt delay before first publish gt e Adds a publisher at the indicated machine s IP address according to the following setup parameters If more than one symbol is provided separated by then each symbol must have a corresponding publishing rate In this case the publisher will publish more than one stockquote symbol publication set e eg 0 11 ADD PO 10 0 1 10 demo bin stockquote startSQpublisher sh i P0 s NXTL JDSU SCON r 43 8 24 8 14 6 d 0 b socket 10 0 1 1 21979 B1 lt time s gt ADD lt id gt lt nodeIPAddr gt startSQsubscriber sh i SO s lt subscription1 gt lt sul b lt broker_uri gt e Adds a subscriber at the indicated machine s IP address according to the following setup parameters The subscriber can issue multiple subscriptions if provided with more than one subscription each separated by e e g 637 86 ADD SO 10 0 1 10 demo bin stockquote startSQsubscriber sh i S0 s class eq ST b socket 10 0 1 2 21979 B1 lt time s gt REMOVE lt id gt lt nodeIPAddr gt Removes a process with the given id by killing its pro cess on the remote machine 7 The PADRES Monitor The PADRES Monitor is a specialized PADRES client capable of graphically displaying the overlay topol ogy More precisely
8. A Below is the PANDA topology file that captures the setup illustrated in Table 2 This topology file utilizes PANDA s 2 phase deployment where PANDA ensures all brokers marked with time 0 0 are fully up and connected in phase I before deploying clients with time gt 0 0 in phase II Note even though the commands in the below example are shown broken into multiple lines the actual topology file does not accept new lines in the middle of a command line 12 e o SE OH OSE OSE OSE HE m E oS OSE OSE OE 0 0 ADD BrokerA 10 0 0 ADD BrokerB 10 0 ADD BrokerC 10 Phase 1 deploy the 3 brokers 1 bin startbroker uri socket 10 0 1 1 10000 BrokerA 2 bin startbroker uri socket 10 0 1 2 10001 BrokerB n socket 10 1 10000 BrokerA 3 bin startbroker uri socket 10 0 1 3 10002 BrokerC 2 10001 BrokerB oo oOo gt pi cy ee a n socket 10 Phase 2 deploy Client X and Client Y Client X is a publisher deployed at 1s after successful broker deployment that publishes stock quote publications of symbol ANTP at 60 msgs min to BrokerA with 0 delay before initial publication demo stockquote startSQpublisher sh is the script that starts this automated stock quote publisher 01 ADD ClientX 10 0 1 4 demo bin stockquote startSQpublisher sh i ClientX s ANTP r 60 d 0 b socket 10 0 1 1 10000 BrokerA ClientY is a subscriber deployed at 10s after successful broker deployment that subscribes to class eq STOCK
9. NFO DEBUG Default value INFO 9 PADRES Language In this section we give a short description of the basics of PADRES messages and leave the details of the format of advertisements subscriptions and publications to subsequent sections Predicates in padres are in the form of attributeName op arg triples which define conditional statements A predicate is evaluated as true with an attribute value pair attributeName value whenever the attributeNames are identical and application of the operator on the value arg is evaluated as true Attribute names are strings but attribute values can have different data types Currently PADRES supports string and numerical data types Numer ical values can either be integer float or double The operators op that can be applied to these types are listed in the table that follows Data type Supported operators String eq str lt str le str gt str ge neq str prefix str contains str postfix and isPresent Numerical lt lt gt gt and isPresent Table 6 PADRES language operators PADRES supports a special isPresent operator for all data types This operator is used to say whether an attribute has taken on any value or not For example the following predicate will be matched with any value associated with the attribute price as long as that value is a number i e the matched value should be of the same type as the arg value in the predicate p
10. PADRES User Guide PADRES Development Team July 11 2012 1 Introduction PADRES is a distributed content based publish subscribe system It consists of a set of clients connected to brokers organized in an overlay network A client can be a publisher and or a subscriber Publishers pro duce information that subscribers are possibly interested in publications and subscribers consume them Initially publishers broadcast their publication schemas by issuing advertisements Subscribers register their interest via issuing subscriptions and these subscriptions are routed towards candidate publishers whose advertisements match the subscriptions When a new publication is published it is matched against all the registered subscriptions and routed to the subscribers who sent matching subscriptions A topic based pub sub system makes the routing decisions based on the topic attribute that classifies publications into pre defined classes In contrast the content based routing used in PADRES can use any attribute in the publications subscriptions to make the matching routing decision providing a highly flexible routing mechanism PADRES is also different from many other content based pub sub systems due to its fully decentralized architecture routing decisions are taken in a distributed broker overlay This provides a scalable solution that can span across a large enterprise or even throughout the Internet 2 Installing PADRES Follow the inst
11. blication The attribute could be any value as long as the attribute appears in the publication with the right data type For instance price isPresent twenty will not be matched by an attribute price with an associated value 20 or any other numerical value but will be matched by an attribute price with any value of type string How do we then distinguish between a double and a float value We infer the type of an attribute from its value in a subscription or an advertisement For numbers PADRES can distinguish integer short int from double float It cannot distinguish double from float Currently all non integer numbers are doubles 21
12. cally sending connection requests For detailed description of the options used with the startbroker command run it with help option Section 4 2 Now start the clients startclient i ClientX b socket localhost 1100 BrokerA startclient i ClientY b socket localhost 1102 BrokerC The option i specifies the unique ID for the client and b is used to specify the broker it should connect to The startclient command will bring up a GUI for each client which can be used to interact with the client Section 5 3 The layout of the client GUI is shown in Figure 2 Figure 2 PADRES RMI client GUI The client GUI provides a way to perform the basic operations in a PADRES network advertise sub scribe and publish A client can publish only after it has sent out matching advertisements For example if the Client X is going to publish temperature data from the Toronto area it must first advertise by issuing an advertisement as below enter this command into the user interface area of Client X a class eq temp area eg tor value lt 100 Here the client advertises that it is going to publish temperature data for Toronto area with values less than 100 degree Celsius Note that the interface is space sensitive If the Client Y wants to be informed when the temperature in city of Toronto drops below zero it can register a subscription via its GUI as below enter this command into the user interface area o
13. commands from a text file Each command in the file must be placed in separate lines printsubs Print the list of subscriptions that has been already disseminated from this client The list will show the subscription IDs which can be used to unsubscribe printadvs Similar to the above command but displays the list of advertisements 5 2 Configuring PADRES Client PADRES clients uses SPADRES_HOME etc client properties as their default configuration file Like the broker you can use the c command line option to specify your own configuration file 10 Client ID The identifier of the client Mandatory In configuration file client id Command line option i Available values A unique identifier Default value Client1 Broker to connect The URI of the broker to which the client is to conect Even though it is an optional parameter at the invocation of the client it has to connect to a broker before it can function An initially unconnected client can make a connection to a broker using the connect command Section 5 1 In configuration file client remoteBrokers Command line option b Available values An URI of a broker Default value No of connection retries The number of times the client tries to connect to the assigned Broker before it reports a failure and quits In configuration file connection retries Command line option retry Available values An integer Default value 5 Pause between retries
14. d classonly Print all the subscriptions stored in the matcher The nohead option will prevent the message headers from printing and the classonly option will only print the subscription class predicates e printadvs nohead classonly Print all the advertisements stored in the matcher The nohead option will prevent the message headers from printing and the classonly option will only print the advertisement class predicates e info Print all the essential details about the Broker broker ID broker URI JVM version and platform OS e sub lt subscription string gt Inject a subscription directly into the broker The broker itself will be the subscriber e adv lt advertisement string gt Inject an advertisement directly into the broker The broker itself will be the advertiser e pub lt publication string gt Inject a publication directly into the broker The broker itself will be the publisher e unsub lt subscription ID gt lt subscription ID gt Unsubscribe the subscription s with the specified ID s e unadv lt advertisement ID gt lt advertisement ID gt Unadvertise the advertisement s with the specified ID s e batch lt filename gt Execute a batch of commands listed in the given plain text file One command per line the above commands can be used If the broker is configured to use the Jess library for content based matching the following additional commands are available to interact with the Jes
15. d configuration file for PADRES logging engine Useful set of configuration options are as follows Note that only the logging directory parameter can be changed using a command line option and this command line option is to be used with the startbroker Section 4 2 and startclient Section 5 3 commands Other parameters do not have any command line options Logging Directory The directory path name where the log files are to be placed In configuration file Log dir Command line option 11 Available values a directory pahtname Default value padres logs Timestamp in log file name This adds a time stamp to the log file names Itis only useful for testing the 18 system see the PADRES developers guide In configuration file time in filename Available values ON OFF Default value OFF Basic log level This parameter defines the basic log level of the system Any classes see below requesting logs below this level will not create any output In configuration file 1og4j root Logger Available values ERROR WARN INFO DEBUG this is the order of priority Default value WARN Log levels of the PADRES classes The log levels of the PADRES classes There is one line for each class that requires logging To enable the logging on one class the log level in the line has to be greater or equal to the log level of the basic log level see above In configuration file 1og4j logger lt ClassName gt Available values ERROR WARN I
16. e web browser is running i e the broker machine is not behind a firewall The web management provides a similar interface like the console interface and accepts the same set of commands Section 4 3 However the exit command is not applicable here 5 PADRES Clients PADRES provides a number of clients which provides the basic functionality of pub sub operations Only the interface to these clients differs GUIClient This provides a GUI interface to the client commands When you run the startclient script in the bin directory this is the client that gets invoked by default CLIClient This provides a command line interface to the client Use the startclient script with the cli option to invoke this WebClient This provides a user interface via a web page The default configuration and relevant data for this client is found at etc web client You can start this client using the startclient script with web option However it accepts an additional command line option wport lt port number gt The port_number has to be unique for a client Once you start a WebClient you can access its interface via the URL http localhost lt port number gt Note that each WebClient you start will require separate port number and browser window for its interface SwingRM Deployer It is similar to the GUIClient but created mostly to be used in the PADRES demos The primary difference from the above is this client s ability to launch a batch of pub sub
17. essage Trace specific subscription messages as they traverse the federa tion Untrace Message Cancel tracing of messages Set of Adv View selected broker s set of advertisements Set of Sub View selected broker s set of subscriptions Properties View selected broker s system properties Failure Detection Set selected broker s failure detection properties In the popup menu that appears Heartbeat properties can be configured Heart beats are small messages sent between brokers that facilitate fail ure detection Trace by ID Trace publications as they traverse the network by entering the application name of the deployment Table 4 Broker menu items Menu Item Description Batch Message Inject publications subscriptions and advertisements as a batch job from a text file Batch Message Incremen Inject publications subscriptions and advertisements one by one tal as a batch job from a text file Table 5 First Broker menu items 8 PADRES Log Files There is a detailed logging system in the PADRES design By default the system logs only the error and exceptions But the level of logging can be tuned by a configuration file 8 1 Configuring PADRES Logs PADRES uses the log4j properties file to configure the logging of information from PADRES compo nents At present there is no command line option available to specify a user define
18. f Client Y s class eq temp area eq tor value lt 0 Now Client X can publish new temperature data via its GUI enter this command into the user interface area of Client X p class temp area tor value 10 This data will be routed through the broker overlay and the Client Y will be informed about it via the output area of its GUI this message should have appeared in the client output area of Client Y upon sending of the previous publication Got Publication class temp area tor value 10 Thu Jun 19 17 14 58 GMT 2008 Advertisements and subscriptions have an attribute operator value tuple format whereas publications are formatted as attribute value pairs More information on adv sub pub patterns and operators can be found at Note currently the client GUI does not support unadvertise and unsubscribe A graphical representation of the PADRES overlay can be viewed using the PADRES monitor To start the monitor use the following command startmonitor b socket localhost 1100 BrokerA This will bring up the monitor GUI and automatically connect to BrokerA After some time the monitor will show the current system layout as in Figure B You can also use Main Refresh Federation or press F5 to refresh the view Figure 3 PADRES monitor GUI Instructions on the basic usage of the monitor can be found in Section 7 You can stop the clients and the monito
19. f IBM stock is greater than 50 AND the HP stock price is greater than 40 The second subscription is satisfied when the stock price of IBM is greater than 50 OR the price of HP stock is greater than 40 Cross references between atomic portions of composite subscriptions is also supported For example cs class eq stock name eq S X price lt 50 amp class eq stock name eq S X price gt 40 is satisfied when a company s stock is between 40 50 The S indicates that the following variable X is of type string Similarly ISY means that variable Y is an integer Format of Publication A publication is conjunction of attribute value pairs p class stock name IBM price 45 20 9 2 FAQ Is the below publication example correct class stock name IBM price 45 No stock should be quoted since it is a string as class stock Can a value be non existant in a publication No each attribute value pair must have a value Hence the following publication is invalid class foot product price color gree What s the syntax for the use of isPresent isPresent is an operator for subscriptions and advertisements It is used exactly in the same way normal operators are used The arg element in the predicates identify the data type associated with the attribute isPresent does not care about the concrete value in a pu
20. from PADRES federation without exiting the Moni tor Refresh Federation Refresh the graphical display to ensure it is up to date Apply Layout Execute one of seven algorithms on the graphical display to change arrangement of nodes Global Failure Detection Enable disable the global failure detection functionality of PADRES When enabled the monitor graphically indicates halted brokers and broken links in the federation Show Edge Message Counter Display a message counter per link The counters increment as messages traverse the links Hide Edge Message Counter Hide all message counters Edge Throughput Indicator Enable disable and reset the edge throughput indicator When ON OFF RESET enabled edges in graphical display will increase in thickness as messages traverse the links Exit Exit the monitor Table 3 Main menu items Note most of the features in the Broker menu Table 4 are only available when a broker is selected A broker can be selected by clicking on a cyan node in the graphical display 7 3 Monitor Demos Monitor features can be demonstrated by executing the Historic databasejand Failure Detection demos 17 Menu Item Description Stop Broker Manually stop selected broker Resume Broker Resume a stopped broker Trace PUB Message Trace specific publication messages as they traverse the federa tion Trace SUB M
21. hat contains configurations for the database supporting historic queries Useful only when the historic query option is enabled In configuration file padres dopropertyfile Command line option d Available values a file pathname Default value SPADRES_HOME etc db db properties Cyclic Network Specifies whether the PADRES topology allows cycles In configuration file padres cycles Command line option cy Available values OFF FIXED DYNAMIC Default value OFF Subscription Covering To enable subscription covering In configuration file padres covering subscription Command line option s Available values OFF LAZY ACTIVE Default value OFF Advertisement Covering To enable advertisement covering In configuration file padres covering advertisement Command line option a Available values OFF ACTIVE Default value OFF Publication Conformation With this enabled publishers can publish only after issuing matching adver tisements In configuration file padres pub conformcheck Command line option pubc Available values ON OFF Default value ON Publication Tracing To enable tracing of publications by class name In configuration file padres traceall Command line option None Available values ON OFF Default value OFF Console Interface Whether to enable a console interface to the broker The command line option does not accept any argument In configuration file padres consoleinterface Command line option
22. he code e Values in default configuration file e Values in user specified configuration file e Values specified as command line options For example command line options would overwrite configurations in the user specified configuration file which in turn overwrite those in the default configuration file 4 2 The startbroker Command startbroker is the shell script to invoke a PADRES broker See Section 4 1 for the broker specific options It can also accept JVM specific options like Xms and Xmx 4 3 Console Interface The PADRES broker provides a console interface which can be used to interact with the broker and mon itor its state By default the console interface is disabled it can be activated at launch time with the cli command line option Section 4 2 or with the padres consoleinterface ON property in the broker con figuration file Section 4 1 If the console interface is to be activated the broker should be started at a shell prompt where stdin stdout are available to the broker With the console interface activated the broker will provide a Broker gt gt gt prompt at which various commands can be entered to interact with the broker The followings are the commands available in the console interface e help command Print all the available commands If a command is specified print the description of that particular command e exit or Ctrlitd Exit the shell and terminates the broker e printsubs nohea
23. in PANDA By default PANDA assumes that Java is installed in the home directory under java Additionally the script named javahome located in the distribution s etc panda setup must be present in the home directory of the remote nodes Uploading of the PADRES binaries and libraries can be done by using the upload command to upload and extract tarball containing the required files Please complete PANDA s configuration Section before proceeding More help regarding PANDA commands can be found by typing help in the PANDA console Using the PADRES system configuration in Table 2 to deploy Broker A using PANDA first start panda by running the startpanda command Once you get the PANDA console type the following command into PANDA s console startpanda Type help or for help gt 0 0 ADD BrokerA 10 0 1 1 bin startbroker uri socket 10 0 1 1 10000 BrokerA The 0 0 value at the beginning of the line marks the time when the broker should be started 0 0 implies an immediate action also see below All node addresses must strictly be IP addresses To stop the deployed broker issue the command below Note that the ID of the process and IP address of the node must match with the previous ADD command gt 0 0 REMOVE BrokerA 10 0 1 1 Instead of typing ADD REMOVE commands separately for each broker client process it is possible to group all the console commands into a file called a PANDA topology file to be imported into PAND
24. net card In this case you have to explicitly specify using this host option the IP address of the network interface of the client machine through which the client reaches the broker 6 PANDA PADRES Automated Node Deployer and Administrator PANDA allows you to deploy and manage a net work of brokers and clients In addition to starting and terminating remote processes PANDA also supports installing uninstalling of rpms and tarballs and fetching and cleaning of log files at remote nodes The user has complete freedom of the topology to deploy as all deployment details are captured in a user defined topology file Internally PANDA consists of a Java program with many helper shell scripts that interact with the remote nodes With PANDA you no longer need to manually log into every single node to do anything as everything is now automated The current version of PANDA is only available on the Linux platform requires OpenSSH 3 9 or later with options ConnectTimeout and StrictHostKeyChecking requires all remote machines to be accessible via ssh remote machines must host ssh servers and have the screen application installed 6 1 Running a Distributed PADRES System with PANDA Before deploying any PADRES processes you must make sure that the machines on which you wish to run padres has Java 6 and screen installed and both PADRES binaries and libraries Installation of Java 6 and screen on PlanetLab can be done via the install command
25. ng commands can be invoked only after a topology file has been successfully loaded install Install RPMs on all nodes you specified in the loaded input file such as the Java SDK It does not hurt to run this command on nodes that already has the RPMs installed because nodes will not download the rpm file again nor reinstall it uninstall Removes RPMs sitting in tmp of remote nodes specified in the loaded topology file It does not hurt to run this command on nodes that have already uninstalled its RPM files reinstall Runs uninstall then install in sequence upload URL Deploys the padres code to all broker nodes you specified It does this by downloaded the tarball and extracting it by simply doing tar xzvf tar gz after which the tar ball is deleted If you do not specify a tar ball URL then the default one specified in panda properties will be used clean lt all log gt e all cleans the entire home directory e log removes log files located under SHOME build deploy lt auto gt Starts the 2 phase deployment process by first setting up a stabilized broker network before deploying the clients With the auto flag panda will not give any prompts deploy phase 1 and deploys phase 2 only after monitoring phase 1 deployment is complete stop time s Stops the experiment by killing all broker and client processes on their respective nodes after a certain period of time from now If time is not specified then it means n
26. operations listed in a text file Each line in such a text file is a command recognized by the above SwingRMI Client 5 1 Client Commands All the clients accept the same set of pub sub commands exit quit Exit the client setid lt client_id gt Set client identifier Caution Avoid using this command if you do use it before any other client operations help lt command gt Output help on the specified command If issued without a command a list of all available commands will be displayed info Print information about the client brokerinfo To print the information about the broker the client is connected to connect lt broker_uri gt Connect to a broker disconnect lt broker_uri gt Disconnect from a broker adv class eq Advertise The alias a also works sub class eq Subscribe The alias s also works csub lt op gt Produce a composite subscription Each term inside a pair of braces represents a normal subscription The operator op can be amp represents AND or represents OR The alias es also works pub class Publish The alias p also works unsub lt id gt Unsubscribe id is a valid ID of a previously disseminated subscription See the printsubs com mand below unadv lt id gt Similar to the above command but used to un advertise See printadvs command below file lt file path gt Process a batch of pub sub
27. otocol 4 1 Configuring PADRES Broker By default SPADRES_HOME etc broker properties is used to configure PADRES brokers It has the format of a standard Java property file Users can specify their own configuration file using the c command line option Section 4 2 The followings are the available configuration parameters and their descriptions Instead to specifying these parameters in the configuration file different command line options can be used to specify the parameters with the startbroker command Section 4 2 Configuration File The property file to read to configuration options of the broker In configuration file Command line option c Available values a file pathname Default value SPADRES_HOME etc broker properties Broker ID ID of the broker mandatory In configuration file padres brokerID Command line option given as the part of uri option Available values An identifier string that does not include hyphen or _ underscore characters Default value Broker URI unique URI of the broker In configuration file padres uri Command line option uri Available values A string in the format of lt comm_protocol gt lt hostname gt lt port gt lt broker_id gt see Section 3 Default value rmi localhost 1099 Brokerl Neighbors Lists of URIs of neighbor brokers If broker A and B are neighbors only one of them need to specify the neighbor In configuration file pad
28. ow get lt logs errors gt e logs Retrieves the log files from remote machines and store them into a local directory called as LOGS lt current date gt e errors Grep for ERROR messages in Exception log files under the build directory No log files are retrieved in doing so auto URL to tarball Performs all steps in one shot so you can sit back and relax drink a coffee and eat a bun while waiting These steps include 15 1 install 2 upload 3 deploy The following can be entered into both the console and the simulation file If entered onto the console then PANDA assumes that the node on which the broker client runs is already set up and contains the desired PADRES build In short inputs entered onto the console are like loading an input from the file and automatically calling the start command Note Commands i e ADD etc are NOT case sensitive Note ADD addresses should take the form of IP address and port number s For example 10 0 0 1 1099 Or 10 0 0 2 45045 21979 1099 Tip Start all your brokers at time Os then your clients Os to allow PANDA to freeze your client deployment time until all brokers have started and neighbor links estabilshed lt time s gt ADD lt id gt lt nodeIPaddr gt startbroker uri lt broker_uri gt n lt neighborl1 neighbo e Adds a broker with the given broker ID at the indicated machine with limited JVM memory e e g 0 0 ADD Bl 10 0 1 2 bin startbroker uri socket 10 0 1 2 2
29. r just by closing the GUIs The brokers can be stopped using the stopbroker command stopbroker BrokerA stopbroker BrokerB stopbroker BrokerC 3 2 Running a Distributed PADRES System Using the same topology as in Figure I but running each process on a separate node we have a slightly different setup compared to the previous configuration as shown in Table 2 Broker A Broker B Broker C ID BrokerA ID BrokerB ID BrokerC Location 10 0 1 1 Location 10 0 1 2 Location 10 0 1 3 Port A 10000 Port B 10001 Port C 10002 Neighbors Broker B Neighbors Broker A Broker C Neighbors Broker B Client X Client Y Location 10 0 1 4 Location 10 0 1 5 Broker Broker A Broker Broker C Table 2 Distributed PADRES system parameters You may start brokers and clients individually using the same technique above by logging into each node separately Be sure to update the broker URIs with the correct hostnames and ports 4 PADRES Broker The broker provides the core matching and routing capabilities in the PADRES overlay It accepts messages from clients publishers and subscribers performs content based routing of those messages and notifies subscribers when the publications matching their subscriptions are found A broker can service multiple clients Communications between broker and clients and between brokers are always achieved via a pub sub pr
30. res remoteBrokers Command line option n Available values Comma separated without space in between remote broker URIs Default value Connection Retry Limit The number of times a broker tries to connect to the specified neighbors In configuration file padres remoteBrokers retry limit Command line option r1 Available values An integer Default value 30 Connection Retry Pause The number of seconds a broker pauses between connection retries In configuration file padres remoteBrokers retry pauseTime Command line option rp Available values An integer Default value 10 Managers Optional internal components to instantiate to provide additional features In configuration file padres managers Command line option b Available values DB Default value Matching Engine Specifies the type of matching engine to be used In configuration file padres routerFactory Command line option None Available values NewRete Jess Default value NewRete Note Due to licensing issues the Jess library is not included in the release choosing Jess for this option will result in a run time exception If you want to use the Jess engine you have to download the library yourself and place the jess jar archive in the SPADRES_HOME 1ib directory Note that only version 6 0 of the Jess library is tested with PADRES and you might have to pay a licensing fee for the Jess library Database property file The property file t
31. rice isPresent 0 On the other hand price isPresent twenty maches any associated value of type String for attribute price 19 9 1 PADRES Message Format Messages can have three different types e Advertisements e Subscriptions e Publications Every message in PADRES should have a fixed attribute class of type String Format of Advertisements An advertisement is a list of comma separated predicates The advertisement defines all the attributes that can possibly appear in future publications In fact valid publications use all or subset of the attributes defined in an advertisement An example is provided below a class eqg stock name eg IBM price gt 50 Format of Subscriptions The format of atomic subscription is the same as that of an advertisement s class eq stock name eq IBM price gt 60 However PADRES supports composite subscriptions as well A composite subscription consists of atomic subscriptions connected by logical operators amp or Variables are allowed as well For example 1 cs class eq stock name eq IBM price gt 50 amp class eq stock name eq HP price gt 40 class eq stock name eq IBM price gt 50 lal class eq stock name eq HP price gt 40 2 cs The first composite subscription is satisfied when the price o
32. ructions from the PADRES download page 3 Running PADRES A PADRES overlay is deployed by instantiating a set of brokers and clients Section i First you have to decide on the topology of the broker overlay and client broker connections You can additionally instantiate a monitor in order to monitor the status of the brokers and clients For this user guide let us consider the PADRES system topology shown in Figure I Figure 1 A simple PADRES network PADRES system components are typically deployed on different physical machines However it may also be advantageous to learn to run the whole system in a single physical machine for verification and debugging purposes We first describe how to instantiate the system shown in Figure I on a single physical machine and then in a distributed setting 3 1 Running a PADRES System in a Single Physical Machine The parameters of the PADRES system shown in Figure running on a single machine is given in Table I The port numbers are chosen arbitrarily However it is better to choose high port numbers to avoid conflicts with the ports used by other services Broker A Broker B Broker C ID BrokerA ID BrokerB ID BrokerC Location localhost Location localhost Location localhost Port A 1100 Port B 1101 Port C 1102 Client X Client Y Location localhost Location localhost Broker Broker A Broker Broker C
33. s based matching engine If the Jess library is not available these commands will always print an error message e srt lt command gt Runs the given command on the Jess SRT e prt lt command gt Runs the given command on the Jess PRT e flush lt class gt lt class gt Flush facts from Jess based PRT 4 4 Web Management Interface In addition to the console interface Section 4 3 a web management interface also can be enabled It is enabled using the padres management interface property in the configuration file or the m option in the command line Section KI The interface is configured through a configuration file which is set to etc broker mipropertyfile by default The configuration options available are Server Port Number The port number of the web server to be instantiated In configuration file http port Available values An integer Default value 9595 Monitor name The identifier of the management interface In configuration file monitor name Available values A unique identifier Default value MyMonitor When the web management interface is enabled the interface can be accessed through a web browser at the URL http lt hostname gt lt port_no gt e g http localhost 9595 The hostname should be the hostname of the machine where the broker is instantiated The interface can be accessed from any machine using the correct URL provided that the broker machine is reachable from the machine where th
34. the monitor displays PADRES brokers clients and their interconnections It develops the view of a overlay by connecting to a broker in the federation and then subscribing to BROKER_INFO mes sages published by individual brokers It uses the information received in these publications to construct and graphically display the network topology 16 7 1 Basics Getting Started In order to view a PADRES federation the client must first connect to a broker in the federation This can be done as follows Connecting to a Federation 1 In the PADRES menu bar click Main Connect to Federation 2 In the ensuing pop up window enter the hostname i e localhost or IP address in the Hostname field and the port number in the Port field 3 Click OK A PADRES federation should now appear on screen Note that cyan nodes represent brokers and blue nodes represent clients Edges represent connections between brokers and clients and between brokers To disconnect from the federation click Main gt Disconnect from Federation 7 2 Advanced Features The monitor supports certain operations on a broker or the entire federation All features can be invoked from the Monitor menu bar Descriptions of each of the menu items are listed in Tables BA and 5 Menu Item Description Connect to Federation Connect to a PADRES federation and graphically display the net work topology Disconnect Federation Disconnect
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