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Sun GlassFish Enterprise Server 21 Performance Tuning Guide

1. Cache Settings Pool Settings cache idle refresh cache timeout removal victim period pool max pool idle Type of resize max cache in timeout in selection in steady resize pool timeout in Bean quantity size seconds seconds policy seconds pool size quantity size seconds Entity X X X X X X X X X Entity X X X X X X X X X X Read only Message X X X Driven Bean Commit Option The commit option controls the action taken by the EJB container when an EJB component completes a transaction The commit option has a significant impact on performance There are two possible values for the commit option m Commit option B When a transaction completes the bean is kept in the cache and retains its identity The next invocation for the same primary key can use the cached instance The EJB container will call the bean s ejbLoad method before the method invocation to synchronize with the database a Commit option C When a transaction completes the EJB container calls the bean s ejbPassivate method the bean is disassociated from its primary key and returned to the free pool The next invocation for the same primary key will have to get a free bean from the pool set the PrimaryKey on this instance and then call ejbActivate on the instance Again the EJB container will call the bean s ejbLoad before the method invocation to synchronize with the database Option B avo
2. The performance capacity ofa particular hardware configuration The hardware resources required to sustain specified application load and performance You can estimate these values through careful performance benchmarking using an application with realistic data sets and workloads 24 Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 General Tuning Concepts Y ToDetermine Capacity 1 Determine performance on a single CPU First determine the largest load that a single processor can sustain You can obtain this figure by measuring the performance ofthe application on a single processor machine Either leverage the performance numbers of an existing application with similar processing characteristics or ideally use the actual application and workload in a testing environment Make sure that the application and data resources are tiered exactly as they would be in the final deployment 2 Determine vertical scalability Determine how much additional performance you gain when you add processors That is you are indirectly measuring the amount of shared resource contention that occurs on the server for a specific workload Either obtain this information based on additional load testing of the application on a multiprocessor system or leverage existing information from a similar application that has already been load tested Running a series of performance tests on one to eight CPUs in incremental steps genera
3. EXAMPLE 4 1 Heap Configuration on Solaris This is an exmple heap configuration used by Enterprise Server on Solaris for large applications Xms3584m Xmx3584m verbose gc Dsun rmi dgc client gcInterval 3600000 Survivor Ratio Sizing The SurvivorRatio parameter controls the size of the two survivor spaces For example XX SurvivorRatio 6 sets the ratio between each survivor space and eden to be 1 6 each survivor space will be one eighth ofthe young generation The default for Solaris is 32 If survivor spaces are too small copying collection overflows directly into the old generation If survivor spaces are too large they will be empty At each GC the JVM determines the number oftimes an object can be copied before it is tenured called the tenure threshold This threshold is chosen to keep the survivor space half full Use the option XX PrintTenuringDistribution to show the threshold and ages ofthe objects in the new generation It is useful for observing the lifetime distribution ofan application Rebasing DLLs on Windows When the JVM initializes it tries to allocate its heap using the Xms setting The base addresses of Application Server DLLs can restrict the amount of contiguous address space available causing JVM initialization to fail The amount of contiguous address space available for Java memory varies depending on the base addresses assigned to the DLLs You can increase the amount of contiguous address space availa
4. This value does not limit the number of connections but it can cause connection hashing to take longer The default size is 512 To make lookups more efficient set the value to half of the number of concurrent TCP connections that are expected on the server You can set this value only in etc system and it becomes effective at boot time Use the following command to get the current number of TCP connections netstat nP tcp wc l 96 Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Linux Configuration File Descriptor Setting On the Solaris OS setting the maximum number of open files property using ulimit has the biggest impact on efforts to support the maximum number of RMI IIOP clients To increase the hard limit add the following command to etc system and reboot it once set rlim fd max 8192 Verify this hard limit by using the following command ulimit a H Once the above hard limit is set increase the value of this property explicitly up to this limit using the following command ulimit n 8192 Verify this limit by using the following command ulimit a For example with the default ulimit of 64 a simple test driver can support only 25 concurrent clients but with ulimit set to 8192 the same test driver can support 120 concurrent clients The test driver spawned multiple threads each of which performed a JNDI lookup and repeatedly called the same business method with a thin
5. gt Additionally create an etc sysctl conf file and append it with the following values lt begin Disables packet forwarding net ipv4 ip forward 0 Enables source route verification net ipv4 conf default rp filter 1 Disables the magic sysrq key kernel sysrq 0 fs file max 65536 vm bdflush 100 1200 128 512 15 5000 500 1884 2 net ipv4 ip local port range 1024 65000 net core rmem max 262143 net core rmem default 262143 net ipv4 tcp rmem 4096 131072 262143 net ipv4 tcp wmem 4096 131072 262143 net ipv4 tcp sack 0 net ipv4 tcp timestamps 0 kernel shmmax 67108864 For further information on tuning Solaris system see the Solaris Tunable Parameters Reference Manual Tuning for Solaris on x86 98 The following are some options to consider when tuning Solaris on x86 for Application Server and HADB File Descriptors on page 100 TP Stack Settings on page 99 Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Tuning for Solaris on x86 Some of the values depend on the system resources available After making any changes to etc system reboot the machines File Descriptors Add or edit the following lines in the etc system file set rlim fd max 65536 set rlim fd cur 65536 set sq max size 0 set tcp tcp conn hash size 8192 set autoup 60 set pcisch pci stream buf enable 0 These settings affect the file descriptors IP Stack Settings A
6. Tuning the Enterprise Server Java Runtime System m Chapter 4 Tuning the Java Runtime System m Operating system and platform m Chapter 5 Tuning the Operating System and Platform High availability features Chapter 6 Tuning for High Availability Y Performance Tuning Sequence Application developers should tune applications prior to production use Tuning applications often produces dramatic performance improvements System administrators perform the remaining steps in the following list after tuning the application or when application tuning has to wait and you want to improve performance as much as possible in the meantime Ideally follow this sequence of steps when you are tuning performance 1 Tune your application described in Chapter 2 Tuning Your Application 2 Tune the server described in Chapter 3 Tuning the Enterprise Server Chapter 3 Tuning the Enterprise Server 3 Tune the high availability database described in Chapter 6 Tuning for High Availability 4 Tune the Java runtime system described in Chapter 4 Tuning the Java Runtime System 5 Tune the operating system described in Chapter 5 Tuning the Operating System and Platform 18 Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Understanding Operational Requirements Understanding Operational Requirements Before you begin to deploy and tune your application on the Application Server it is imp
7. 1 tmpz expr tmp 1 done done Putall network interfaces into a single group For example ifconfig ipge group webserver ifconfig ipgel group webserver Start Options In some situations performance can be improved by using large page sizes The start options to use depend on your processor architecture The following examples show the options to start the 32 bit Enterprise Server and the 64 bit Enterprise Server with 4 Mbyte pages Chapter5 Tuning the Operating System and Platform 105 Tuning UltraSPARC T1 Based Systems 106 ma To start the 32 bit Enterprise Server with 4 Mbyte pages use the following options LD PRELOAD 32 usr lib mpss so 1 export LD PRELOAD 32 export MPSSHEAP 4M bin startserv unset LD PRELOAD 32 unset MPSSHEAP To start the 64 bit Enterprise Server with 4 Mbyte pages use the following options LD PRELOAD 64 usr lib 64 mpss so 1 export LD PRELOAD 64 export MPSSHEAP 4M bin startserv unset LD PRELOAD 64 unset MPSSHEAP Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 gt CHAPTER 6 Tuning for High Availability This chapter discusses the following topics Tuning HADP on page 107 Tuning the Enterprise Server for High Availability on page 116 Configuring the Load Balancer on page 120 Tuning HADB The Application Server uses the high availability database HADB to store persistent session state data To o
8. Therefore copying is inherently expensive and overusing it can reduce performance significantly Assign null to Variables That Are No Longer Needed Explicitly assigning a null value to variables that are no longer needed helps the garbage collector to identify the parts of memory that can be safely reclaimed Although Java provides memory management it does not prevent memory leaks or using excessive amounts of memory An application may induce memory leaks by not releasing object references Doing so prevents the Java garbage collector from reclaiming those objects and results in increasing amounts of memory being used Explicitly nullifying references to variables after their use allows the garbage collector to reclaim memory One way to detect memory leaks is to employ profiling tools and take memory snapshots after each transaction A leak free application in steady state will show a steady active heap memory after garbage collections Declare Methods as final Only If Necessary Modern optimizing dynamic compilers can perform inlining and other inter procedural optimizations even if Java methods are not declared final Use the keyword final as it was originally intended for program architecture reasons and maintainability Only if you are absolutely certain that a method must not be overridden use the final keyword Declare Constants as static final The dynamic compiler can perform some constant folding optimizations easily w
9. Enterprise Server 65 HTTP Service Settings 66 Buffer Length The size in bytes ofthe buffer used by each ofthe request processing threads for reading the request data from the client Adjust the value based on the actual request size and observe the impact on performance In most cases the default should suffice If the request size is large increase this parameter Keep Alive Both HTTP 1 0 and HTTP 1 1 support the ability to send multiple requests across a single HTTP session A server can receive hundreds of new HTTP requests per second If every request was allowed to keep the connection open indefinitely the server could become overloaded with connections On Unix Linux systems this could easily lead to a file table overflow The Application Server s Keep Alive system addresses this problem A waiting keep alive connection has completed processing the previous request and is waiting for a new request to arrive on the same connection The server maintains a counter for the maximum number of waiting keep alive connections If the server has more than the maximum waiting connections open when a new connection waits for a keep alive request the server closes the oldest connection This algorithm limits the number of open waiting keep alive connections If your system has extra CPU cycles incrementally increase the keep alive settings and monitor performance after each increase When performance saturates stops improving the
10. GC algorithms A generational memory system divides the heap into a few carefully sized partitions called generations The efficiency of a generational memory system is based on the observation that most of the objects are short lived As these objects accumulate a low memory condition occurs forcing GC to take place The heap space is divided into the old and the new generation The new generation includes the new object space eden and two survivor spaces The JVM allocates new objects in the eden space and moves longer lived objects from the new generation to the old generation The young generation uses a fast copying garbage collector which employs two semi spaces survivor spaces in the eden copying surviving objects from one survivor space to the second Objects that survive multiple young space collections are tenured meaning they are copied to the tenured generation The tenured generation is larger and fills up less quickly So it is garbage collected less frequently and each collection takes longer than a young space only collection Collecting the tenured space is also referred to as doing a full generation collection The frequent young space collections are quick a few milliseconds while the full generation collection takes a longer tens of milliseconds to a few seconds depending upon the heap size Other GC algorithms such as the Concurrent Mark Sweep CMS algorithm are incremental They divide the full GC into several
11. HADB uses this disk space for temporary storage of the log buffer during high load conditions Tuning Data Device Size To increase the size ofthe HADB data devices use the following command hadbm set TotalDatadeviceSizePerNode This command restarts all the nodes one by one to apply the change For more information on using this command see Configuring HADB in Sun GlassFish Enterprise Server 2 1 High Availability Administration Guide Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Tuning HADB Note hadbm does not add data devices to a running database instance Placing HADB files on Physical Disks For best performance data devices should be allocated on separate physical disks This applies if there are nodes with more than one data device or if there are multiple nodes on the same host Place devices belonging to different nodes on different devices Doing this is especially important for Red Hat AS 2 1 because HADB nodes have been observed to wait for asynchronous I O when the same disk is used for devices belonging to more than one node An HADB node writes information warnings and errors to the history file synchronously rather than asynchronously as output devices normally do Therefore HADB behavior and performance can be affected any time the disk waits when writing to the history file This situation is indicated by the following message in the history file BEWARE last f
12. HIGH LOAD informational messages in the history files All the relevant messages will contain tuple Log or simply Log and a description of the internal resource contention that occurred Under normal operation the log is reported as 70 to 80 full This is because space reclamation is said to be lazy HADB requires as much data in the log as possible to recover from a possible node crash Use the following command to display information on log buffer size and use hadbm resourceinfo logbuf For example output might look like this Node No Avail Free Size 0 44 42 44 42 The columns in the output are Node No The node number Avail Size of buffer in megabytes Free Size Free size in MB when the data volume is larger than the buffer The entire buffer is used at all times Change the size of the log buffer with the following command hadbm set LogbufferSize This command restarts all the nodes one by one for the change to take effect For more information on using this command see Configuring HADB in Sun GlassFish Enterprise Server 2 1 High Availability Administration Guide InternalLogbufferSize The node internal log nilog contains information about physical as opposed to logical row level operations at the local node For example it provides information on whether there are disk block allocations and deallocations and B tree block splits This buffer is maintained in shared memory and is als
13. However this must be done after carefully analyzing the database table usage patterns Set the database transaction isolation level with the Admin Console on the Resources gt JDBC gt Connection Pools gt PoolName page For more information on tuning JDBC connection pools see JDBC Connection Pool Settings on page 77 Tuning Message Driven Beans This section provides some tips to improve performance when using JMS with message driven beans MDBs Use getConnection JMS connections are served from a connection pool This means that calling getConnection on a Queue connection factory is fast Caution Previous to version 8 1 it was possible to reuse a connection with a servlet or EJB component That is the servlet could call getConnection inits init method and then continually call getSession for each servlet invocation If you use JMS within a global transaction that no longer works applications can only call getSession once for each connection After than the connection must be closed which doesn t actually close the connection it merely returns it to the pool This is a general feature of portable Java EE 1 4 applications the Sun Java System Application Server enforces that restriction where previous Java EE 1 3 based application servers did not Tune the Message Driven Bean s Pool Size The container for message driven beans MDB is different than the containers for entity and session beans In the MDB
14. a trade off between these four metrics For example a large young generation likely maximizes throughput but at the cost of footprint and promptness Conversely using a small young generation and incremental GC will minimize pauses and thus increase promptness but decrease throughput JVM diagnostic output will display information on pauses due to garbage collection If you start the server in verbose mode use the command asadmin start domain verbose domain then the command line argument verbose gc prints information for every collection Here is an example of output ofthe information generated with this JVM flag GC 50650K gt 21808K 76868K 0 0478645 secs GC 51197K gt 22305K 76868K 0 0478645 secs GC 52293K gt 23867K 76868K 0 0478645 secs Full GC 52970K gt 1690K 76868K 0 54789968 secs On each line the first number is the combined size of live objects before GC the second number is the size of live objects after GC the number in parenthesis is the total available space which is the total heap minus one of the survivor spaces The final figure is the amount of time that the GC took This example shows three minor collections and one major collection In the first GC 50650 KB of objects existed before collection and 21808 KB of objects after collection This means that 28842 KB of objects were dead and collected The total heap size is 76868 KB The collection process required 0 0478645 seconds Other useful monitor
15. beans can be cached to improve performance TABLE3 1 Bean Type Pooling or Caching Bean Type Pooled Cached Stateless Session Yes No Stateful Session No Yes Entity Yes Yes The difference between a pooled bean and a cached bean is that pooled beans are all equivalent and indistinguishable from one another Cached beans on the contrary contain conversational state in the case of stateful session beans and are associated with a primary key in the case of entity beans Entity beans are removed from the pool and added to the cache on ejbActivate and removed from the cache and added to the pool on ejbPassivate ejbActivate is called by the container when a needed entity bean is not in the cache ej bPassivate is called by the container when the cache grows beyond its configured limits Chapter3 Tuning the Enterprise Server 53 EJB Container Settings 54 Note If you develop and deploy your EJB components using Sun Java Studio then you need to edit the individual bean descriptor settings for bean pool and bean cache These settings might not be suitable for production level deployment Tuning the EJB Pool A bean in the pool represents the pooled state in the EJB lifecycle This means that the bean does not have an identity The advantage of having beans in the poolis that the time to create a bean can be saved for a request The container has mechanisms that create pool objects in the background to save the t
16. container sessions and threads are attached to the beans in the MDB pool This design makes it possible to pool the threads for executing message driven requests in the container Tune the Message Driven bean s pool size to optimize the concurrent processing of messages Setthe size ofthe MDB pool to based on all the parameters of the server taking other applications into account For example a value greater than 500 is generally too large Youcan configure MDB pool settings in the Admin Console at Configurations config name EJB Container MDB Settings You can also set it with asadmin as follows asadmin set server mdb container max pool size value Chapter2 Tuning Your Application 47 EJB Performance Tuning 48 Cache Bean Specific Resources Use the setMessageDrivenContext or ejbCreate method to cache bean specific resources and release those resources from the ej bRemove method Limit Use of JMS Connections When designing an application that uses JMS connections make sure you use a methodology that sparingly uses connections by either pooling them or using the same connection for multiple sessions The JMS connection uses two threads and the sessions use one thread each Since these threads are not taken from a pool and the resultant objects aren t pooled you could run out of memory during periods of heavy usage One workaround is to move createTopicConnection into the init ofthe servlet Make sure t
17. eie detail da dette diede 60 Connection OUGUe io ouvre diea diia dun add dtd det P OU Tuning the HTTP Service osea nid nt nn ne Tuning HTTP Listener Settings ORB Sti BS o seed paeiiianie eiie di pid deae me dH CORR coutsscashacgensoca Geacgenaceedsscacnacasensnae OVerview RTE dede e D dederit limes diente teits 70 Howa Client Connects to the ORD treten erede ect eiae 70 Monitoring the ORB nn anna unes 70 Tuning the ORB M Thread Pool Sizing Examining IIOP Messages 4 Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Contents Improving ORB Performance with Java Serialization sse 75 Thread POOL Settings enu beet buddies idee raa dp e e e d Dau OPE VT d TS 76 Tuning Thread Pools Unix Linux only testet teret ra ie P eae dn 76 RESOULCES M N JDBC Connection Pool Settings Connector Connection Pool Settin G6 go nn nait FURORE nan 80 Tuning the Java Runtime System Java Virtual Machine Settings Managing Memory and Garbage Collection ss 84 Tuning the Garbage Collector smilies 84 Tracing Garbage Collection tiens 86 Other Garbage Collector Settings tno ns quae nine iet 86 Tunine the Jaya EIeap 45 2 pe e eto ae candi de o eret o degere edid e ans 87 Rebasing DLEs On WindOWs aidant in tricis dit ie e deed enia 89 Further Information cett oth are ete i dr ERR d nere ter RU REE 91 T
18. following property m name accessLoggingEnabled value false You can set the following access log properties Rotation enabled disabled Enable rotation to ensure that the logs don t run out of disk space Rotation Policy ime based or size based Size based is the default Rotation Interval Request Processing On the Request Processing tab of the HTTP Service page tune the following HTTP request processing settings Thread Count Initial Thread Count Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 HTTP Service Settings Request Timeout Buffer Length Thread Count The Thread Count parameter specifies the maximum number of simultaneous requests the server can handle The default value is 5 When the server has reached the limit or request threads it defers processing new requests until the number of active requests drops below the maximum amount Increasing this value will reduce HTTP response latency times In practice clients frequently connect to the server and then do not complete their requests In these cases the server waits a length of time specified by the Request Timeout parameter Also some sites do heavyweight transactions that take minutes to complete Both of these factors add to the maximum simultaneous requests that are required If your site is processing many requests that take many seconds you might need to increase the number of maximum simultaneo
19. incremental pieces This provides a high probability of small pauses This process comes with an overhead and is not required for enterprise web applications Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Managing Memory and Garbage Collection When the new generation fills up it triggers a minor collection in which the surviving objects are moved to the old generation When the old generation fills up it triggers a major collection which involves the entire object heap Both HotSpot and Solaris JDK use thread local object allocation pools for lock free fast and scalable object allocation So custom object pooling is not often required Consider pooling only if object construction cost is high and significantly affects execution profiles Choosing the Garbage Collection Algorithm Pauses during a full GC of more than four seconds can cause intermittent failures in persisting session data into HADB While GC is going on the Application Server isn t running If the pause is long enough the HADB times out the existing connections Then when the application server resumes its activities the HADB generates errors when the application server attempts to use those connections to persist session data It generates errors like Failed to store session data Transaction Aborted or Failed to connect to HADB server To prevent that problem use the CMS collector as the GC algorithm This collector can c
20. information on how to configure RMI IIOP for multiple application server instances in a cluster Chapter 9 RMI HOP Load Balancing and Failover in Sun GlassFish Enterprise Server 2 1 High Availability Administration Guide When tuning the client ORB for load balancing and connections consider the number of connections opened on the server ORB Start from a low number of connections and then increase it to observe any performance benefits A connection to the server translates to an ORB thread reading actively from the connection these threads are not pooled but exist currently for the lifetime of the connection Thread Pool Sizing After examining the number of inbound and outbound connections as explained above tune the size of the thread pool appropriately This can affect performance and response times significantly The size computation takes into account the number of client requests to be processed concurrently the resource number of CPUs and amount of memory available on the machine and the response times required for processing the client requests Setting the size to a very small value can affect the ability of the server to process requests concurrently thus affecting the response times since requests will sit longer in the task queue On the other hand having a large number of worker threads to service requests can also be detrimental because they consume system resources which increases concurrency This can mean that
21. jar stateful entity bean ItemEnt bean pool idle timeout in seconds 0 steady pool size 0 total beans destroyed num threads waiting 0 num beans in pool 54 max pool size 2147483647 pool resize quantity 0 total beans created 255 0 The monitoring command below gives the bean pool statistics for a stateless bean asadmin get user admin host e4800 241 a port 4848 m test application testEjbMon ejb module slsb stateless session bean slsb bean pool idle timeout in seconds 200 steady pool size 32 total beans destroyed num threads waiting 0 num beans in pool 4 max pool size 1024 pool resize quantity 12 total beans created 42 12 Tuning the bean involves charting the behavior of the cache and pool for the bean in question over a period oftime Iftoo many passivations are happening and the JVM heap remains fairly small then the max cache size or the cache idle timeout in seconds can be increased If garbage Chapter 2 Tuning Your Application 33 EJB Performance Tuning 34 collection is happening too frequently and the pool size is growing but the cache hit rate is small then the pool idle timeout in seconds can be reduced to destroy the instances Note Specifying a max pool size of zero 0 means that the pool is unbounded The pooled beans remain in memory unless they are removed by specifying a small interval for pool idle timeout in seconds For production systems specifying the
22. memory segments in use You can configure the size of some ofthe shared memory segments Ifthese segments are too small performance suffers and user transactions are delayed or even aborted Ifthe segments are too large then the physical memory is wasted You can configure the following parameters DataBufferPoolSize on page 110 LogBufferSize on page 111 InternalLogbufferSize on page 112 NumberOfLocks on page 113 Timeouts on page 115 DataBufferPoolSize The HADB stores data on data devices which are allocated on disks The data must be in the main memory before it can be processed The HADB node allocates a portion of shared memory for this purpose Ifthe allocated database buffer is small compared to the data being processed then disk I O will waste significant processing capacity In a system with write intensive operations for example frequently updated session states the database buffer must be big enough that the processing capacity used for disk I O does not hamper request processing The database buffer is similar to a cache in a file system For good performance the cache must be used as much as possible so there is no need to wait for a disk read operation The best performance is when the entire database contents fits in the database buffer However in most cases this is not feasible Aim to have the working set of the client applications in the buffer Also monitor the disk I
23. not be optimal for a development environment This chapter discusses the following topics Process Overview on page 17 Understanding Operational Requirements on page 19 General Tuning Concepts on page 23 Further Information on page 26 Process Overview The following table outlines the overall administration process and shows where performance tuning fits in the sequence TABLE1 1 Performance Tuning Roadmap Step Description of Task Location of Instructions 1 Design Decide on the high availability topology Deployment Planning Guide and set up the Application Server and if you are using HADB for session persistence high availability database HADB systems 2 Capacity Planning Make sure the systems have Deployment Planning Guide sufficient resources to perform well Process Overview TABLE1 1 Performance Tuning Roadmap Continued Step Description of Task Location of Instructions 3 Installation If you are using HADB for session Installation Guide persistence ensure that the HADB software is installed 4 Deployment Install and run your applications Application Deployment Guide Familiarize yourself with how to configure and T s Administration Guide administer the Enterprise Server 5 Tuning Tune the following items The following chapters m Applications m Chapter 2 Tuning Your Application m Enterprise Server m Chapter 3
24. number of times the bean state has to be checkpointed into the persistent store Stateless Session Beans Stateless session beans are more readily pooled than entity or the stateful session beans Valid values for steady pool size pool resize quantity and max pool size are the best tunables for these type of beans Set the steady pool size to greater than zero if you want to pre populate the pool This way when the container comes up it creates a pool with steady pool size number of beans By pre populating the pool it is possible to avoid the object creation time during method invocations Setting the steady pool size to a very large value can cause unwanted memory growth and can result in large garbage collection times pool resize quantity determines the rate of growth as well as the rate of decay ofthe pool Setting it to a small value is better as the decay behaves like an exponential decay Setting a small max pool size can cause excessive object destruction and as a result excessive object creation as instances are destroyed from the pool if the current pool size exceeds max pool size Read Only Entity Beans Read only entity beans cache data from the database Application Server supports read only beans that use both bean managed persistence BMP and container managed persistence CMP Ofthe two types CMP read only beans provide significantly better performance In the EJB lifecycle the EJB container calls the ejbLoad m
25. only bean add the following to the EJB deployment descriptor sun ejb jar xml lt is read only bean gt true lt is read only bean gt lt refresh period in seconds gt 600 lt refresh period in seconds gt Refresh period An important parameter for tuning read only beans is the refresh period represented by the deployment descriptor entity ref resh period in seconds For CMP beans the first access to a bean loads the bean s state The first access after the refresh period reloads the data from the database All subsequent uses ofthe bean uses the newly refreshed data until another refresh period elapses For BMP beans an ejbLoad method within an existing transaction uses the cached data unless the refresh period has expired in which case the container calls ejbLoad again This parameter enables the EJB component to periodically refresh its snapshot of the database values it represents If the refresh period is less than or equal to 0 the bean is never refreshed from the database the default behavior if no refresh period is given Pre fetching Container Managed Relationship CMR Beans If a container managed relationship CMR exists in your application loading one bean will load all its related beans The canonical example of CMR is an order orderline relationship where you have one Order EJB component that has related OrderLine EJB components In previous releases of the application server to use all those beans would req
26. param name gt genSt rAsCharArray lt param name gt lt param value gt t rue lt param value gt lt init param gt lt load on startup gt 3 lt load on startup gt lt servlet gt Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 EJB Container Settings EJB Container Settings The EJB Container has many settings that affect performance As with other areas use monitor the EJB Container to track its execution and performance Monitoring the EJB Container Monitoring the EJB container is disabled by default Enable monitoring with the Admin Console under Configurations gt config name gt Monitoring Set the monitoring level to LOW for to monitor all deployed EJB components EJB pools and EJB caches Set the monitoring level to HIGH to also monitor EJB business methods Tuning the EJB Container The EJB container caches and pools EJB components for better performance Tuning the cache and pool properties can provide significant performance benefits to the EJB container Set EJB cache and pool settings in the Admin Console Configurations gt config name gt EJB Container EJB Settings The pool settings are valid for stateless session and entity beans while the cache settings are valid for stateful session and entity beans Overview of EJB Pooling and Caching Both stateless session beans and entity beans can be pooled to improve server performance In addition both stateful session beans and entity
27. see Chapter 9 Configuring Security in Sun GlassFish Enterprise Server 2 1 Administration Guide The type of authentication mechanism chosen may require additional hardware for the deployment Typically a directory server executes on a separate server and may also require a backup for replication and high availability Refer to Sun Java System Directory Server documentation for more information on deployment sizing and availability guidelines An authenticated user s access to application functions may also need authorization checks If the application uses the role based Java EE authorization checks the application server performs some additional checking which incurs additional overheads When you perform capacity planning you must take this additional overhead into account Encryption For security reasons sensitive user inputs and application output must be encrypted Most business oriented web applications encrypt all or some ofthe communication flow between the browser and Application Server Online shopping applications encrypt traffic when the user is completing a purchase or supplying private data Portal applications such as news and media typically do not employ encryption Secure Sockets Layer SSL is the most common security framework and is supported by many browsers and application servers The Application Server supports SSL 2 0 and 3 0 and contains software support for various cipher suites It also supports integra
28. server and application server tier If SSL is enabled hardware capacity planning must be take into account the encryption policy and mechanisms J fsoftware encryption is to be employed Whatisthe expected performance overhead for every tier in the system given the security requirements Whatarethe performance and throughput characteristics of various choices For information on how to encrypt the communication between web servers and Application Server please refer to Chapter 9 Configuring Security in Sun GlassFish Enterprise Server 2 1 Administration Guide Hardware Resources The type and quantity of hardware resources available greatly influence performance tuning and site planning The Application Server provides excellent vertical scalability It can scale to efficiently utilize multiple high performance CPUs using just one application server process A smaller number of application server instances makes maintenance easier and administration less expensive Also deploying several related applications on fewer application servers can improve performance due to better data locality and reuse of cached data between co located applications Such servers must also contain large amounts of memory disk space and network capacity to cope with increased load The Application Server can also be deployed on large farms of relatively modest hardware units Business applications can be partitioned across various server in
29. size of the young generation relative to the old generation is controlled by NewRatio For example setting XX NewRatio 3 means that the ratio between the old and young generation is 1 3 the combined size of eden and the survivor spaces will be fourth of the heap By default the Enterprise Server is invoked with the Java HotSpot Server JVM The default NewRatio for the Server JVM is 2 the old generation occupies 2 3 of the heap while the new generation occupies 1 3 The larger new generation can accommodate many more short lived objects decreasing the need for slow major collections The old generation is still sufficiently large enough to hold many long lived objects To size the Java heap Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Managing Memory and Garbage Collection Decide the total amount of memory you can afford for the JVM Accordingly graph your own performance metric against young generation sizes to find the best setting Make plenty of memory available to the young generation The default is calculated from NewRatio and the Xmx setting Larger eden or younger generation spaces increase the spacing between full GCs But young space collections could take a proportionally longer time In general keep the eden size between one fourth and one third the maximum heap size The old generation must be larger than the new generation For up to date defaults see Java HotSpot VM Options
30. the JVM Settings page in the Admin Console Restart the Application Server Heap Configuration on Windows This is an example heap configuration used by Sun GlassFish Enterprise Server for heavy server centric applications on Windows as set in the domain xml file lt jvm options gt Xms1400m lt jvm options gt lt jvm options gt Xmx1400m lt jvm options gt For more information on rebasing see MSDN documentation for rebase utility Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Further Information Further Information For more information on tuning the JVM see Java HotSpot VM Options Frequently Asked Questions About the Java HotSpot Virtual Machine Performance Documentation for the Java HotSpot VM Java performance web page Monitoring and Management for the Java Platform J2SE 5 0 The jvmstat monitoring utility Chapter4 Tuning the Java Runtime System 91 92 CHAPTER 5 Tuning the Operating System and Platform This chapter discusses tuning the operating system OS for optimum performance It discusses the following topics Server Scaling on page 93 Solaris 10 Platform Specific Tuning Information on page 95 Tuning for the Solaris OS on page 95 Linux Configuration on page 97 Tuning for Solaris on x86 on page 98 Tuning for Linux platforms on page 100 Tuning UltraSPARC T1 Based Systems on page 103 Server Scaling This section provides rec
31. threads take longer to acquire shared structures in the EJB container thus affecting response times The worker thread pool is also used for the EJB container s housekeeping activity such as trimming the pools and caches This activity needs to be accounted for also when determining the size Having too many ORB worker threads is detrimental for performance since the server has to maintain all these threads The idle threads are destroyed after the idle thread timeout period Examining IIOP Messages It is sometimes useful to examine the IIOP messages passed by the Enterprise Server To make the server save IIOP messages to the server Log file set the JVM option Dcom sun CORBA ORBDebug giop Use the same option on the client ORB The following is an example of IIOP messages saved to the server log Note in the actual output each line is preceded by the timestamp such as 29 Aug 2002 22 41 43 INFO 27179 CORE3282 stdout Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 ORB Settings nn en D D D D D D D PHcER Message Thread ORB Client side Reader conn to 192 18 80 118 1050 5 main createFromStream type is 4 MessageBase Thread ORB Client side Reader conn to 192 18 80 118 1050 5 main Message GIOP version 1 2 MessageBase Thread ORB Client side Reader conn to 192 18 80 118 1050 5 main ORB Max GIOP Version 1 2 Message Thread ORB Client side Reader conn to 192 18 80 118 1050 5 ma
32. transaction modifies the data the version number is unchanged at the end of both transactions and both succeed But now the transactions can run in parallel If two transactions occasionally modify the same EJB component one will succeed and one will fail and can be retried using the new values which can still be faster than serializing all access to the EJB component if the retries are infrequent enough though now your application logic has to be prepared to perform the retry operation To use version consistency the database schema for a particular table must include a column where the version can be stored You then specify that table in the sun cmp mapping xml deployment descriptor for a particular bean lt entity mapping gt lt cmp field mapping gt Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 EJB Performance Tuning lt cmp field mapping gt lt consistency gt lt check version of accessed instances gt lt column name gt 0rderTable VC VERSION NUMBER lt column name gt check version of accessed instances lt consistency gt lt entity mapping gt In addition you must establish a trigger on the database to automatically update the version column when data in the specified table is modified The Application Server requires such a trigger to use version consistency Having such a trigger also ensures that external applications that modify the EJB data will not conflict with EJB trans
33. value at 20 second increments then inconsistencies will result For example consider an online auction scenario as follows Bidding starts at 5 in 60 seconds the value recorded will be 8 three 20 second intervals During the next 40 seconds the client starts incrementing the price The value the client sees is 10 During the client s 20 second rest the Application Server stops and starts in 10 seconds As a result the latest value recorded at the 60 second interval 8 is be loaded into the session The client clicks again expecting to see 11 but instead sees is 9 which is incorrect So to avoid data inconsistencies take into the account the expected behavior of the application when adjusting the reap interval Disable Dynamic JSP Reloading On a production system improve web container performance by disabling dynamic JSP reloading To do so edit the default web xml file in the config directory for each instance Change the servlet definition for a JSP file to look like this lt servlet gt lt servlet name gt jsp lt servlet name gt lt servlet class gt org apache jasper servlet JspServlet lt servlet class gt lt init param gt lt param name gt development lt param name gt lt param value gt false lt param value gt lt init param gt lt init param gt lt param name gt xpoweredBy lt param name gt lt param value gt t rue lt param value gt lt init param gt lt init param gt lt
34. view monitoring information with the Admin Console open the page Stand Alone Instances gt instance name Monitor Tuning Thread Pools Unix Linux only Configure thread pool settings through the Admin Console at Configurations gt config name gt Thread Pools Since threads on Unix Linux are always operating system OS scheduled as opposed to user scheduled Unix Linux users do not need to use native thread pools Therefore this option Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Resources is not offered in a Unix Linux user interface However it is possible to edit the OS scheduled thread pools and add new thread pools if needed using the Admin Console Resources JDBC Connection Pool Settings on page 77 Connector Connection Pool Settings on page 80 JDBC Connection Pool Settings For optimum performance of database intensive applications tune the JDBC Connection Pools managed by the Enterprise Server These connection pools maintain numerous live database connections that can be reused to reduce the overhead of opening and closing database connections This section describes how to tune JDBC Connection Pools to improve performance J2EE applications use JDBC Resources to obtain connections that are maintained by the JDBC Connection Pool More than one JDBC Resource is allowed to refer to the same JDBC Connection Pool In such a case the physical connection pool is shared by
35. 9 ORB Settings set serverInstance iiop service orb system monitoringEnabled true reconfig serverInstance Connection Statistics The following statistics are gathered on ORB connections m total inbound connections Total inbound connections to ORB m total outbound connections Total outbound connections from ORB Use this command to get ORB connection statistics asadmin get monitor serverInstance iiop service orb system orb connection Thread Pools The following statistics are gathered on ORB thread pools thread pool size Number of threads in ORB thread pool m waiting thread count Number of thread pool threads waiting for work to arrive Use this command to get ORB thread pool statistics asadmin get monitor serverInstance iiop service orb system orb thread pool Tuning the ORB Tune ORB performance by setting ORB parameters and ORB thread pool parameters You can often decrease response time by leveraging load balancing multiple shared connections thread pool and message fragment size You can improve scalability by load balancing between multiple ORB servers from the client and tuning the number of connection between the client and the server The following table summarizes the tunable ORB parameters TABLE3 3 Tunable ORB Settings Path ORB modules Server settings RMI IIOP from application client to application communication steady thread pool size max thread pool size server infrastructure t
36. EJB Performance Tuning 32 The Enterprise Server s high performance EJB container has numerous parameters that affect performance Individual EJB components also have parameters that affect performance The value of individual EJB components parameter overrides the value of the same parameter for the EJB container The default values are designed for a single processor computer system change them to optimize for other system configurations This section covers the following topics Goals on page 32 Monitoring EJB Components on page 32 General Guidelines on page 35 Using Local and Remote Interfaces on page 36 Improving Performance of EJB Transactions on page 38 Using Special Techniques on page 39 Tuning Tips for Specific Types of EJB Components on page 42 JDBC and Database Access on page 46 Tuning Message Driven Beans on page 47 Goals The goals of EJB performance tuning are Increased speed Cache as many beans in the EJB caches as possible to increase speed equivalently decrease response time Caching eliminates CPU intensive operations However since memory is finite as the caches become larger housekeeping for them including garbage collection takes longer Decreased memory consumption Beans in the pools or caches consume memory from the Java virtual machine heap Very large pools and caches degrade performance because they require longer and more frequent garbage collection cycles Im
37. Generally do not store large objects as HttpSession variables Don t cache transaction data in HttpSession Access to data in an HttpSession is not transactional Do not use it as a cache of transactional data which is better kept in the database and accessed using entity beans Transactions will rollback upon failures to their original state However stale and inaccurate data may remain in HttpSession objects The Enterprise Server provides read only bean managed persistence entity beans for cached access to read only data Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Java Server Page and Servlet Tuning Configuration and Deployment Tips Follow these configuration tips to improve performance These tips are intended for production environments not development environments To improve class loading time avoid having excessive directories in the server CLASSPATH Put application related classes into JAR files HTTP response times are dependent on how the keep alive subsystem and the HTTP server is tuned in general For more information see HTTP Service Settings on page 60 Cache servlet results when possible For more information see Chapter 8 Developing Web and SIP Applications in Sun GlassFish Enterprise Server 2 1 Developers Guide Ifan application does not contain any EJB components deploy the application as a WAR file not an EAR file Optimize SSL Optimize SSL b
38. O If HADB performs many disk read operations this means that the database is low on buffer space The database buffer is partitioned into blocks of size 16KB the same block size used on the disk HADB schedules multiple blocks for reading and writing in one I O operation Use the hadbm deviceinfo command to monitor disk use For example hadbm deviceinfo details will produce output similar to this NodeNo TotalSize FreeSize Usage 0 512 504 1 1 512 504 1 The columns in the output are TotalSize size of device in MB Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Tuning HADB FreeSize free size in MB Usage percent used Use the hadbm resourceinfo command to monitor resource usage for example the following command displays data buffer pool information hadbm resourceinfo databuf NodeNo Avail Free Access Misses Copy on write 0 32 0 205910260 8342738 400330 1 32 0 218908192 8642222 403466 The columns in the output are Avail Size of buffer in Mbytes Free Free size when the data volume is larger than the buffer The entire buffer is used at all times Access Number of times blocks that have been accessed in the buffer Misses Number of block requests that missed the cache user had to wait for a disk read a Copy on write Number of times the block has been modified while it is being written to disk For a well tuned system the number of misses an
39. Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide S S microsystems Sun Microsystems Inc 4150 Network Circle Santa Clara CA 95054 U S A Part No 820 4343 10 Copyright 2009 Sun Microsystems Inc 4150 Network Circle Santa Clara CA 95054 U S A All rights reserved Sun Microsystems Inc has intellectual property rights relating to technology embodied in the product that is described in this document In particular and without limitation these intellectual property rights may include one or more U S patents or pending patent applications in the U S and in other countries U S Government Rights Commercial software Government users are subject to the Sun Microsystems Inc standard license agreement and applicable provisions ofthe FAR and its supplements This distribution may include materials developed by third parties Parts ofthe product may be derived from Berkeley BSD systems licensed from the University of California UNIX is a registered trademark in the U S and other countries exclusively licensed through X Open Company Ltd Sun Sun Microsystems the Sun logo the Solaris logo the Java Coffee Cup logo docs sun com OpenSolaris Java and Solaris are trademarks or registered trademarks of Sun Microsystems Inc or its subsidiaries in the U S and other countries All SPARC trademarks are used under license and are trademarks or registered trademarks of SPARC International Inc in the U S and other coun
40. able auto deployment with the Admin Console under Stand Alone Instances server Admin Server on the Advanced Applications Configuration tab Use Pre compiled JavaServer Pages Compiling JSP files is resource intensive and time consuming Pre compiling JSP files before deploying applications on the server will improve application performance When you do so only the resulting servlet class files will be deployed You can specify to precompile JSP files when you deploy an application through the Admin Console or DeployTool You can also specify to pre compile JSP files for a deployed application with the Admin Console under Stand Alone Instances gt server Admin Server on the Advanced Applications Configuration tab Disable Dynamic Application Reloading If dynamic reloading is enabled the server periodically checks for changes in deployed applications and automatically reloads the application with the changes Dynamic reloading is intended for development environments and is also incompatible with session persistence To improve performance disable dynamic class reloading Disable dynamic class reloading for an application that is already deployed with the Admin Console under Stand Alone Instances server Admin Server on the Advanced Applications Configuration tab Logger Settings 50 The Application Server produces writes log messages and exception stack trace output to the log file in the logs directory of the instance apps
41. ache and Pool Tuning Tips Follow these tips when using the EJB cache and pools to improve performance Explicitly call remove Allow stateful session EJB components to be removed from the container cache by explicitly calling ofthe remove method in the client Tune the entity EJB components pool size Entity Beans use both the EJB pool and cache settings Tune the entity EJB components pool size to minimize the creation and destruction of beans Populating the pool with a non zero steady size before hand is useful for getting better response for initial requests Cachebean specific resources Use the setEntityContext method to cache bean specific resources and release them using the unSetEntityContext method Load related data efficiently for container managed relationships CMRs For more information see Pre fetching Container Managed Relationship CMR Beans on page 44 ma Identify read only beans Configure read only entity beans for read only operations For more information see Read Only Entity Beans on page 43 Using Local and Remote Interfaces This section describes some considerations when EJB components are used by local and remote clients Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 EJB Performance Tuning Prefer Local Interfaces An EJB component can have remote and local interfaces Clients not located in the same application server instance as the bean remo
42. actions in progress For example the following DDL illustrates how to create a trigger for the Order table CREATE TRIGGER OrderTrigger BEFORE UPDATE ON OrderTable FOR EACH ROW WHEN new VC VERSION NUMBER old VC VERSION NUMBER DECLARE BEGIN NEW VC VERSION NUMBER OLD VC VERSION NUMBER 1 END Request Partitioning Request partitioning enables you to assign a request priority to an EJB component This gives you the flexibility to make certain EJB components execute with higher priorities than others An EJB component which has a request priority assigned to it will have its requests services executed within an assigned threadpool By assigning a threadpool to its execution the EJB component can execute independently of other pending requests In short request partitioning enables you to meet service level agreements that have differing levels of priority assigned to different services Request partitioning applies only to remote EJB components those that implement a remote interface Local EJB components are executed in their calling thread for example when a servlet calls a local bean the local bean invocation occurs on the servlet s thread To enable request partitioning Configure additional threadpools for EJB execution using the Admin Console Add the additional threadpool IDs to the Application Server s ORB You can do this by editing the domain xml file or through the Admin Console Chapter2 Tuning Your Applic
43. ad balancer pings the instance to see if it is healthy Default value is 30 seconds If the response timeout in seconds is optimally tuned and the server doesn t have too much traffic then the default value works well health checker timeout in seconds How long the load balancer waits after pinging an instance The default value is 100 seconds The combination of the health checker s interval in seconds and timeout in seconds values determine how much additional traffic goes from the load balancer plug in to the server instances Chapter 6 Tuning for High Availability 115 Tuning the Enterprise Server for High Availability For more information on configuring the load balancer plug in see Configuring the HTTP Load Balancer in Sun GlassFish Enterprise Server 2 1 High Availability Administration Guide HADB timeouts The sql_client time out value may affect performance Operating System Configuration Ifthe number of semaphores is too low HADB can fail and display this error message No space left on device This can occur either while starting the database or during run time To correct this error configure semaphore settings Additionally you may need to configure shared memory settings Also adding nodes can affect the required settings for shared memory and semaphores For more information see Configuring Shared Memory and Semaphores in Sun GlassFish Enterprise Server 2 1 High Availability Administr
44. ained in the pool default is 8 Maximum Pool Size Maximum number of connections that can be created to satisfy client requests default is 32 Pool Resize Quantity Number of connections to be removed when idle timeout timer expires Idle Timeout Maximum time seconds that a connection can remain idle in the pool default is 300 Max Wait Time Amount of time milliseconds caller waits before connection timeout is sent Chapter6 Tuning for High Availability 119 Configuring the Load Balancer For optimal performance use a pool with eight to 16 connections per node For example if you have four nodes configured then the steady pool size must be set to 32 and the maximum pool size must be 64 Adjust the Idle Timeout and Pool Resize Quantity values based on monitoring statistics For the best performance use the following settings Connection Validation Required Validation Method metadata Transaction Isolation Level repeatable read In addition to the standard attributes add the two following properties cacheDatabaseMetaData false eliminateRedundantEndTransaction true To add a property click the Add Property button then specify the property name and value and click Save For more information on configuring the JDBC connection pool see Tuning JDBC Connection Pools on page 77 Configuring the Load Balancer 120 The Enterprise Server provides a load balancer plugin that can bal
45. alive interval 96 tcp recv hiwat 96 104 tcp rexmit interval initial 96 tcp rexmit interval max 96 tcp rexmit interval min 96 tcp slow start initial 96 tcp smallest anon port 96 tcp time wait interval 95 tcp xmit hiwat 96 104 Thread Count HTTP Service 65 Thread Pool ID ORB 72 thread pool sizing 74 statistics 71 tuning 76 throughput 86 timeouts HADB 115 Total Connections ORB 72 Total Connections Queued 64 transactions connector connection pools 80 EJB components 38 39 EJB transaction attributes 39 isolationlevel 46 47 management for CMT 79 monitoring 58 tuning 59 tuning applications 27 EJBcache 55 56 EJB pool 54 55 JDBC connection pools 77 80 Solaris TCP IP settings 95 theserver 49 thread pools 76 U ulimit 97 userload 24 V Validation Method JDBC Connection Pool 80 variables assigning nullto 28 victim selection policy 56 virtual memory 101 W web container 51 127 Index X x86 98 XA capable data sources 38 39 Xms 88 Xmx 88 XX DisableExplicitGC 87 MaxHeapFreeRatio 88 MaxPermSize 86 MinHeapFreeRatio 88 128 Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009
46. all the resources Monitoring JDBC Connection Pools Statistics gathering is enabled by default for JDBC Connection Pools The following attributes are monitored numConnFailedValidation count Number of connections that failed validation numConnUsed range Number of connections that have been used m numConnFree count Number of free connections in the pool a numConnTimedOut bounded range Number of connections in the pool that have timed out To get the statistics use these commands asadmin get monitor true serverInstance resources jdbc connection pool asadmin get monitor true serverInstance resources jdbc connection pool poolName Tuning JDBC Connection Pools Set JDBC Connection Pool attributes with the Admin Console under Resources JDBC Connection Pools PoolName The following attributes affect performance Pool Size Settings on page 78 Chapter 3 Tuning the Enterprise Server 77 Initial and Mimimum Pool Size Initial and Mimimum Pool Size Maximum Pool Size Pool Resize Quantity Timeout Settings on page 78 Isolation Level Settings on page 79 Connection Validation Settings on page 79 Pool Size Settings The following settings control the size of the connection pool Size ofthe pool when created and its minimum allowable size Upper limit of size ofthe pool Number of connections to be removed when the idle timeout expires Connections that have
47. ance the load of requests among multiple instances which are part of the cluster Note The following section assumes that the server is tuned effectively to service incoming requests Enabling the Health Checker The load balancer periodically checks all the configured Enterprise Server instances that are marked as unhealthy based on the values specified in the health checker element in the loadbalancer xml file Enabling the health checker is optional If the health checker is not enabled periodic health check of unhealthy instances is not performed The load balancer s health check mechanism communicates with the application server instance using HTTP The health checker sends an HTTP request to the URL specified and waits for a response The status code in the HTTP response header should be between 100 and 500 to consider the instance to be healthy To enable the health checker edit the following properties a url Specifies the listener s URL that the load balancer checks to determine its state of health Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Configuring the Load Balancer a interval in seconds Specifies the interval at which health checks of instances occur The default is 30 seconds timeout in seconds Specifies the timeout interval within which a response must be obtained for a listener to be considered healthy The default is 10 seconds If the typical response from the serve
48. ation Solaris Dynamic Tracing DTrace is a comprehensive dynamic tracing framework for the Solaris Operating System OS You can use the DTrace Toolkit to monitor the system The DTrace Toolkit is available through the OpenSolaris project from the DTraceToolkit page http www opensolaris org os community dtrace dtracetoolkit Tuning for the Solaris OS Tuning Parameters on page 95 File Descriptor Setting on page 97 Tuning Parameters Tuning Solaris TCP IP settings benefits programs that open and close many sockets Since the Enterprise Server operates with a small fixed set of connections the performance gain might not be significant The following table shows Solaris tuning parameters that affect performance and scalability benchmarking These values are examples of how to tune your system for best performance TABLE5 1 Tuning Parameters for Solaris Parameter Scope Default Tuned Value Comments rlim_fd_max etc system 65536 65536 Limit of process open file descriptors Set to account for expected load for associated sockets files and pipes if any rlim fd cur etc system 1024 8192 sq max size etc system 2 0 Controls streams driver queue size setting to 0 makes it infinite so the performance runs won t be hit by lack of buffer space Set on clients too Note that setting sq max size to 0 might not be optimal for production systems with high network traffic tcp close wait interval
49. ation 41 EJB Performance Tuning 42 For example enable threadpools named priority 1and priority 2 to the orb element as follows orb max connections 1024 message fragment size 1024 use thread pool ids thread pool 1 priority 1 priority 2 gt Include the threadpool ID in the use thread pool id element of the EJB component s sun ejb jar xml deployment descriptor For example the following sun ejb jar xml deployment descriptor for an EJB component named TheGreeter is assigned to a thread pool named priority 2 sun ejb jar enterprise beans lt unique id gt 1 lt unique id gt lt ejb gt lt ejb name gt TheGreeter lt ejb name gt lt jndi name gt greeter lt jndi name gt use thread pool id priority 1 use thread pool id ejb lt enterprise beans gt lt sun ejb jar gt Restart the Application Server TuningTips for SpecificTypes of EJB Components This section provides tips for tuning various specific types of EJB components Entity Beans on page 42 Stateful Session Beans on page 42 Stateless Session Beans on page 43 Read Only Entity Beans on page 43 Pre fetching Container Managed Relationship CMR Beans on page 44 Entity Beans Depending on the usage ofa particular entity bean one should tune max cache size so that beans that are used less for example an order that is created and never used after the transaction is over are cached less and beans
50. ation Guide Tuning the Enterprise Server for High Availability 116 This section discusses how you can configure the high availability features of Enterprise Server This section discusses the following topics Tuning Session Persistence Frequency on page 117 Session Persistence Scope on page 118 Session Size on page 118 Checkpointing Stateful Session Beans on page 119 Configuring the JDBC Connection Pool on page 119 Descriptor configuration in the web application To ensure highly available web applications with persistent session data the high availability database HADB provides a backend store to save HTTP session data However there is a overhead involved in saving and reading the data back from HADB Understanding the different schemes of session persistence and their impact on performance and availability will help you make decisions in configuring Enterprise Server for high availability In general maintain twice as many HADB nodes as there are application server instances Every application server instance requires two HADB nodes Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Tuning the Enterprise Server for High Availability Tuning Session Persistence Frequency The Enterprise Server provides HTTP session persistence and failover by writing session data to HADB You can control the frequency at which the server writes to HADB by specifying the p
51. ause a drop in throughput for heavily utilized systems because it is running more or less constantly But it prevents the long pauses that can occur when the garbage collector runs infrequently To use the CMS collector Make sure that the system is not using 100 percent of its CPU Configure HADB timeouts as described in the Administration Guide Configure the CMS collector in the server instance To do this add the following JVM options XX UseConcMarkSweepGC XX SoftRefLRUPolicyMSPerMB 1 Additional Information Use the jvmstat utility to monitor HotSpot garbage collection See Further Information on page 91 For detailed information on tuning the garbage collector see Tuning Garbage Collection with the 5 0 Java Virtual Machine Chapter 4 Tuning the Java Runtime System 85 Managing Memory and Garbage Collection 86 Tracing Garbage Collection The two primary measures of garbage collection performance are throughput and pauses Throughput is the percentage ofthe total time spent on other activities apart from GC Pauses are times when an application appears unresponsive due to GC Two other considerations are footprint and promptness Footprint is the working size of the JVM process measured in pages and cache lines Promptness is the time between when an object becomes dead and when the memory becomes available This is an important consideration for distributed systems A particular generation size makes
52. ble by rebasing the Application Server DLLs Chapter4 Tuning the Java Runtime System 89 Managing Memory and Garbage Collection v Before You Begin Example 4 2 See Also 90 To prevent load address collisions set preferred base addresses with the rebase utilty that comes with Visual Studio and the Platform SDK Use the rebase utility to reassign the base addresses of the Application Server DLLs to prevent relocations at load time and increase the available process memory for the Java heap There are a few Application Server DLLs that have non default base addresses that can cause collisions For example a Thensprlibraries have a preferred address of 0x30000000 Theiculibraries have the address of 0x4A 00000 Move these libraries near the system DLLs msvcrt dllis at 0x78000000 to increase the available maximum contiguous address space substantially Since rebasing can be done on any DLL rebase to the DLLs after installing the Application Server To rebasethe Application Server s DLLs To perform rebasing you need Windows 2000 Visual Studio and the Microsoft Framework SDK rebase utility Make install_dir bin the default directory cd install_dir bin Enter this command rebase b 0x6000000 dll Use the dependencywalker utility to make sure the DLLs were rebased correctly For more information see the Dependency Walker website Increase the size for the Java heap and set the JVM Option accordingly on
53. cache size and probably cache idle timeout in seconds Java Message Service Settings The Type attribute that determines whether the Java Message Service JMS is on local or remote system affects performance Local JMS performance is better than remote JMS performance However a remote cluster can provide failover capabilities and can be administrated together so there may be other advantages of using remote JMS For more information on using JMS see Chapter 4 Configuring Java Message Service Resources GlassFish Enterprise Server 2 1 Administration Guide in Sun Transaction Service Settings 58 The transaction manager makes it possible to commit and roll back distributed transactions A distributed transactional system writes transactional activity into transaction logs so that they can be recovered later But writing transactional logs has some performance penalty Monitoring the Transaction Service Transaction Manager monitoring is disabled by default Enable monitoring of the transaction service with the Admin Console at Configurations gt config name gt Monitoring You can also enable monitoring with these commands set serverInstance transaction service monitoringEnabled true reconfig serverInstance Viewing Monitoring Information When you have enabled monitoring of the transaction service view results With Admin Console at Standalone Instances gt server name Monitor Monitor Select transaction s
54. caches calls to setAutoCommit and getMetaData Table name to query when Validation Method is table Whether to close all connections in the pool ifa single validation check fails The default is false One attempt will be made to re establish failed connections Connector Connection Pool Settings From a performance standpoint connector connection pools are similar to JDBC connection pools Follow all the recommendations in the previous section Tuning JDBC Connection Pools on page 77 Transaction Support You may be able to improve performance by overriding the default transaction support specified for each connector connection pool For example consider a case where an Enterprise Information System EIS has a connection factory that supports local transactions with better performance than global transactions If a resource from this EIS needs to be mixed with a resource coming from another resource manager the default behavior forces the use of XA transactions leading to lower performance However by changing the EIS s connector connection pool to use LocalTransaction transaction support and leveraging the Last Agent Optimization feature previously described you could leverage the better performing EIS LocalTransaction implementation For more information on LAO see Configure JDBC Resources as One Phase Commit Resources on page 39 In the Admin Console specify transaction support when you create a new connector connec
55. ch method call Use XA Capable Data Sources Only When Needed When multiple database resources connector resources or JMS resources are involved in one transaction a distributed or global transaction needs to be performed This requires XA capable resource managers and data sources Use XA capable data sources only when two or more data Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 EJB Performance Tuning source are going to be involved in a transaction If a database participates in some distributed transactions but mostly in local or single database transactions it is advisable to register two separate JDBC resources and use the appropriate resource in the application Configure JDBC Resources as One Phase Commit Resources To improve performance oftransactions involving multiple resources the Application Server uses last agent optimization LAO which allows the configuration of one ofthe resources in a distributed transaction as a one phase commit 1PC resource Since the overhead of multiple resource transactions is much higher for a JDBC resource than a message queue LAO substantially improves performance ofdistributed transactions involving one JDBC resource and one or more message queues To take advantage of LAO configure a JDBC resource as a 1PC resource Nothing special needs to be done to configure JMS resources In global transactions involving multiple JDBC resources LAO will still improv
56. components sun ejb jar xml deployment descriptor The EJB cache settings are Chapter 3 Tuning the Enterprise Server 55 Max Cache Size Max Cache Size Cache Resize Quantity Removal Timeout Removal Selection Policy Maximum number of beans in the cache Make this setting greater than one The default value is 512 A value of zero indicates the cache is unbounded which means the size of the cache is governed by Cache Idle Timeout and Cache Resize Quantity The corresponding EJB deployment descriptor attribute is max cache size Number of beans to be created or deleted when the cache is serviced by the server Valid values are from zero to MAX INTEGER and the default is 16 The corresponding EJB deployment descriptor attribute is resize quantity Amount of time that a stateful session bean remains passivated idle in the backup store Ifa bean was not accessed after this interval of time then it is removed from the backup store and will not be accessible to the client The default value is 60 minutes The corresponding EJB deployment descriptor attribute is removal timeout in seconds Algorithm used to remove objects from the cache The corresponding EJB deployment descriptor attribute is victim selection policy Choices are NRU not recently used This is the default and is actually pseudo random selection policy m FIFO first in first out LRU least recently used Cac
57. ction is enabled by default Disable it by adding the following property to domain xml and restart the server property name statsProfilingEnabled value false gt Disabling statistics collection will increase performance You can also view monitoring statistics with the Admin Console The information is divided into the following categories DNS Cache Information dns on page 61 File Cache Information file cache on page 63 Keep Alive keep alive on page 63 DNS Cache Information dns The DNS cache caches IP addresses and DNS names Your server s DNS cache is disabled by default In the DNS Statistics for Process ID All page under Monitor in the web based Administration interface the following statistics are displayed Enabled Ifthe DNS cache is disabled the rest ofthis section is not displayed By default the DNS cache is off Enable DNS caching with the Admin Console by setting the DNS value to Perform DNS lookups on clients accessing the server CacheEntries CurrentCacheEntries MaxCacheEntries The number of current cache entries and the maximum number of cache entries A single cache entry represents a single IP address or DNS name lookup Make the cache as large as the maximum number of clients that access your web site concurrently Note that setting the cache size too high is a waste of memory and degrades performance Setthe maximum size ofthe DNS cache by entering or changing the value in th
58. ctions and thus protects data However it also decreases performance since it effectively serializes all EJB access Version consistency is another approach to protecting EJB data integrity To use version consistency you specify a column in the database to use as a version number The EJB lifecycle then proceeds like this m The first time the bean is used the ej bLoad method loads the bean as normal including loading the version number from the database TheejbStore method checks the version number in the database versus its value when the EJB component was loaded Ifthe version number has been modified it means that there has been simultaneous access to the EJB component and ejbStore throws a ConcurrentModificationException Otherwise ejbStore stores the data and completes as normal The ejbStore method performs this validation at the end ofthe transaction regardless of whether any data in the bean was modified Subsequent uses of the bean behave similarly except that the ejbLoad method loads its initial data including the version number from an internal cache This saves a trip to the database When the ejbStore method is called the version number is checked to ensure that the correct data was used in the transaction Version consistency is advantageous when you have EJB components that are rarely modified because it allows two transactions to use the same EJB component at the same time Because neither
59. d hence the number of reads must be very small compared to the number of writes The example numbers above show a miss rate of about 4 200 million access and 8 million misses The acceptability of these figures depends on the client application requirements Tuning DataBufferPoolSize To change the size of the database buffer use the following command hadbm set DataBufferPoolSize This command restarts all the nodes one by one for the change to take effect For more information on using this command see Configuring HADP in Sun GlassFish Enterprise Server 2 1 High Availability Administration Guide LogBufferSize Before it executes them HADB logs all operations that modify the database such as inserting deleting updating or reading data It places log records describing the operations in a portion of shared memory referred to as the tuple log buffer HADB uses these log records for undoing operations when transactions are aborted for recovery in case of node crash and for replication between mirror nodes Chapter6 Tuning for High Availability 111 Tuning HADB 112 The log records remain in the buffer until they are processed locally and shipped to the mirror node The log records are kept until the outcome commit or abort ofthe transaction is certain If the HADB node runs low on tuple log the user transactions are delayed and possibly timed out Tuning LogBufferSize Begin with the default value Look for
60. dd or edit the following lines in the etc system file set ip tcp squeue wput 1 set ip tcp squeue close 1 set ip ip squeue bind 1 set ip ip squeue worker wait 10 set ip ip squeue profile 0 These settings tune the IP stack To preserve the changes to the file between system reboots place the following changes to the default TCP variables in a startup script that gets executed when the system reboots ndd set dev tcp tcp time wait interval 60000 ndd set dev tcp tcp conn req max q 16384 ndd set dev tcp tcp conn req max q0 16384 ndd set dev tcp tcp ip abort interval 60000 ndd set dev tcp tcp keepalive interval 7200000 ndd set dev tcp tcp rexmit interval initial 4000 ndd set dev tcp tcp rexmit interval min 3000 ndd set dev tcp tcp rexmit interval max 10000 ndd set dev tcp tcp smallest anon port 32768 ndd set dev tcp tcp slow start initial 2 ndd set dev tcp tcp xmit hiwat 32768 ndd set dev tcp tcp recv hiwat 32768 Chapter5 Tuning the Operating System and Platform 99 Tuning for Linux platforms Tuning for Linux platforms 100 To tune for maximum performance on Linux you need to make adjustments to the following File Descriptors on page 100 Virtual Memory on page 101 Network Interface on page 102 Disk I O Settings on page 102 TCP IP Settings on page 102 File Descriptors You may need to increase the number of file descriptors from the default Having a higher n
61. ds more threads are scheduled to be added the next time a request completes The previous backlog is tracked so that n threads are added n is the HTTP Service s Thread Increment parameter until one of the following is true The number of threads increases over time The increase is greater than n The number of session threads minus the backlog is less than n To avoid creating too many threads when the backlog increases suddenly such as the startup of benchmark loads the server makes the decision whether more threads are needed only once every 16 or 32 connections based on how many session threads already exist Chapter 3 Tuning the Enterprise Server 69 ORB Settings ORB Settings 70 The Enterprise Server includes a high performance and scalable CORBA Object Request Broker ORB The ORB is the foundation of the EJB Container on the server Overview The ORB is primarily used by EJB components via RMI IIOP path from an application client or rich client using the application client container RMI IIOP path from another Enterprise Server instance ORB a RMI IIOP path from another vendors ORB In process path from the Web Container or MDB message driven beans container When a server instance makes a connection to another server instance ORB the first instance acts as a client ORB SSL over IIOP uses a fast optimized transport with high performance native implementations of cryptography algorith
62. e January 2009 HTTP Service Settings Tuning HTTP Listener Settings Change HTTP listener settings in the Admin Console under Configurations gt config name gt HTTP Service gt HTTP Listeners gt listener name Network Address For machines with only one network interface card NIC set the network address to the IP address of the machine for example 192 18 80 23 instead of default 0 0 0 0 If you specify an IP address other than 0 0 0 0 the server will make one less system call per connection Specify an IP address other than 0 0 0 0 for best possible performance Ifthe server has multiple NIC cards then create multiple listeners for each NIC Acceptor Threads The Acceptor Threads setting specifies how many threads you want in accept mode on a listen socket at any time It is a good practice to set this to less than or equal to the number of CPUs in your system In the Enterprise Server acceptor threads on an HTTP Listener accept connections and put them onto a connection queue Session threads then pick up connections from the queue and service the requests The server posts more session threads if required at the end of the request The policy for adding new threads is based on the connection queue state Each time a new connection is returned the number of connections waiting in the queue the backlog of connections is compared to the number ofsession threads already created Ifitis greater than the number of threa
63. e Size of DNS Cache field ofthe Performance Tuning page Chapter3 Tuning the Enterprise Server 61 HTTP Service Settings 62 HitRatio The hit ratio is the number of cache hits divided by the number of cache lookups This setting is not tunable Note If you turn off DNS lookups on your server host name restrictions will not work and IP addresses will appear instead of host names in log files Caching DNS Entries Itis possible to also specify whether to cache the DNS entries If you enable the DNS cache the server can store hostname information after receiving it If the server needs information about the client in the future the information is cached and available without further querying specify the size ofthe DNS cache and an expiration time for DNS cache entries The DNS cache can contain 32 to 32768 entries the default value is 1024 Values for the time it takes for a cache entry to expire can range from 1 second to 1 year specified in seconds the default value is 1200 seconds 20 minutes Limit DNS Lookups to Asynchronous Do not use DNS lookups in server processes because they are resource intensive If you must include DNS lookups make them asynchronous Enabled If asynchronous DNS is disabled the rest ofthis section will not be displayed NameLookups The number of name lookups DNS name to IP address that have been done since the server was started This setting is not tunable AddrLookups The n
64. e fitting from benchmark Perform tests while scalability performance CPU gradually increasing the number of CPUs Identify the knee of from the curve where additional CPUs are providing uneconomical additional gains in performance Requires tuning as described in this guide CPUs Perform at each tier and iterate if necessary Stop here if this meets performance requirements Horizontal Increase in Percentage gain per additional Use a well tuned single application server instance as in scalability performance server process and or hardware previous step Measure how much each additional server from node instance and hardware node improves performance additional servers Safety Margins High If the system must cope with Different equations used if high availability is required availability failures size the system to meet requirements performance requirements assuming that one or more application server instances are non functional Excess capacity It is desirable to operate a server 80 system capacity utilization at peak loads may work for most for unexpected at less than its benchmarked installations Measure your deployment under real and peaks peak for some safety margin simulated peak loads Capacity Planning The previous discussion guides you towards defining a deployment architecture However you determine the actual size of the deployment by a process called capacity planning Capacity planning enables you to predict
65. e ipge tx syncq etc system 1 tcp conn req max q ndd dev tcp 128 3000 tcp conn req max q ndd dev tcp 1024 3000 tcp max buf ndd dev tcp 4194304 tcp cwnd max ndd dev tcp 2097152 tcp xmit hiwat ndd dev tcp 8129 400000 To increase the transmit buffer tcp recv hiwat ndd dev tcp 8129 400000 To increase the receive buffer 104 Note that the IPGE driver version is 1 25 25 Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Tuning UltraSPARC T1 Based Systems Disk Configuration If HTTP access is logged follow these guidelines for the disk Write access logs on faster disks or attached storage Ifrunning multiple instances move the logs for each instance onto separate disks as much as possible Enable the disk read write cache Note that if you enable write cache on the disk some writes might be lost if the disk fails Consider mounting the disks with the following options which might yield better disk performance nologging directio noatime Network Configuration If more than one network interface card is used make sure the network interrupts are not all going to the same core Run the following script to disable interrupts allpsr usr sbin psrinfo grep v off line awk print 1 set allpsr numpsr while numpsr gt 0 do shift numpsr expr numpsr 1 tmp 1 while tmp ne 4 do usr sbin psradm i 1 shift numpsr expr numpsr
66. e might have improved considerably In order to do this at every reboot add the sbin hdparm d1 dev hdX line to etc conf d local start etc init d rc local or whatever the startup script is called For information on SCSI disks see System Tuning for Linux Servers SCSI TCP IP Settings To tune the TCP IP settings Add the following entry to etc rc local echo 30 proc sys net ipv4 tcp fin timeout echo 60000 gt proc sys net ipv4 tcp keepalive time echo 15000 gt proc sys net ipv4 tcp keepalive intvl echo 0 proc sys net ipv4 tcp window scaling Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Tuning UltraSPARC T1 Based Systems 2 Add the following to etc sysctl conf Disables packet forwarding net ipv4 ip forward 0 Enables source route verification net ipv4 conf default rp filter 1 Disables the magic sysrq key kernel sysrq 0 net ipv4 ip local port range 1204 65000 net core rmem max 262140 net core rmem default 262140 net ipv4 tcp rmem 4096 131072 262140 net ipv4 tcp wmem 4096 131072 262140 net ipv4 tcp sack 0 net ipv4 tcp timestamps 0 net ipv4 tcp window scaling 0 net ipv4 tcp keepalive time 60000 net ipv4 tcp keepalive intvl 15000 net ipv4 tcp fin timeout 30 3 Add the following as the last entry in etc rc local sysctl p etc sysctl conf 4 Reboot the system 5 Usethis command to increase the size of the transmit buffer tcp rec
67. e performance however not as much as for one JDBC resource In this situation one of the JDBC resources should be configured as 1PC and all others should be configured as XA Use the Least Expensive Transaction Attribute Set the following transaction attributes in the EJB deployment descriptor file ejb jar xmt Options are listed from best performance to worst To improve performance choose the least expensive attribute that will provide the functionality your application needs NEVER TX NOTSUPPORTED TX MANDATORY TX SUPPORTS TX REQUIRED TX REQUIRESNEW ON Qv qm o Io E Using Special Techniques Special performance enhancing techniques are discussed in the following sections Version Consistency on page 39 Request Partitioning on page 41 Version Consistency Note The technique in section applies only to the EJB 2 1 architecture In the EJB 3 0 architecture use the Java Persistence API JPA Chapter2 Tuning Your Application 39 EJB Performance Tuning 40 Use version consistency to improve performance while protecting the integrity of data in the database Since the application server can use multiple copies of an EJB component simultaneously an EJB components state can potentially become corrupted through simultaneous access The standard way of preventing corruption is to lock the database row associated with a particular bean This prevents the bean from being accessed by two simultaneous transa
68. ecycle modules Java EE 5 Tutorial Using Java EE 5 platform technologies and APIs to develop Java EE applications Java WSIT Tutorial Developing web applications using the Web Service Interoperability Technologies WSIT Describes how when and why to use the WSIT technologies and the features and options that each technology supports Administration Guide System administration for the Enterprise Server including configuration monitoring security resource management and web services management Preface TABLEP 1 Books in the Enterprise Server Documentation Set Continued Book Title Description High Availability Administration Setting up clusters working with node agents and using load balancers Guide Administration Reference Editing the Enterprise Server configuration file domain xml Performance Tuning Guide Tuning the Enterprise Server to improve performance Utility commands available with the Enterprise Server written in man page style Includes the asadmin command line interface Reference Manual Default Paths and File Names The following table describes the default paths and file names that are used in this book TABLEP 2 Default Paths and File Names Placeholder Description Default Value as install Represents the base installation directory for Enterprise Server Solaris M and Linux installations non root user users home directory SUNWappserve
69. end store is always current but it degrades performance since all the session data is persisted for every request modified session With the modified session persistence scope the server examines the state of the HTTP session If and only ifthe data has been modified the server saves the session data to HADB This mode yields better performance than session mode because calls to HADB to persist data occur only when the session is modified modified attribute With the modified attribute persistence scope there are no cross references for the attributes and the application uses setAttribute and getAttribute to manipulate HTTP session data Applications written this way can take advantage ofthis session scope behavior to obtain better performance Session Size Itis critical to be aware ofthe impact of HTTP session size on performance Performance has an inverse relationship with the size of the session data that needs to be persisted Session data is stored in HADB in a serialized manner There is an overhead in serializing the data and inserting it as a BLOB and also deserializing it for retrieval Tests have shown that for a session size up to 24KB performance remains unchanged When the session size exceeds 100KB and the same back end store is used for the same number of connections throughput drops by 9096 Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Tuning the Enterprise Server for High Ava
70. ent Authentication Required true false ORB Thread Pool Parameters The ORB thread pool contains a task queue and a pool of threads Tasks or jobs are inserted into the task queue and free threads pick tasks from this queue for execution Do not set a thread pool size such that the task queue is always empty It is normal for a large application s Max Pool Size to be ten times the size of the current task queue The Enterprise Server uses the ORB thread pool to Execute every ORB request Trim EJB pools and caches Thus even when one is not using ORB for remote calls via RMI IIOP set the size of the threadpool to facilitate cleaning up the EJB pools and caches Set ORB thread pool attributes under Configurations gt config name gt Thread Pools gt thread pool ID where thread pool ID is the thread pool ID selected for the ORB Thread pools have the following attributes that affect performance Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 ORB Settings Minimum Pool Size The minimum number of threads in the ORB thread pool Set to the average number of threads needed at a steady RMI HOP load Maximum Pool Size The maximum number of threads in the ORB thread pool Idle Timeout Number of seconds to wait before removing an idle thread from pool Allows shrinking of the thread pool Number of Work Queues In particular the maximum pool size is important to performance For
71. equirement It stops a node increases the InternalLogBufferSize re initializes the internallog device and brings up the node This sequence is performed on all nodes NumberOfLocks Each row level operation requires a lock in the database Locks are held until a transaction commits or rolls back Locks are set at the row BLOB chunk level which means that a large session state requires many locks Locks are needed for both primary and mirror node operations Hence a BLOB operation allocates the same number oflocks on two HADB nodes Whena table refragmentation is performed HADB needs extra lock resources Thus ordinary user transactions can only acquire half ofthe locks allocated Ifthe HADB node has no lock objects available errors are written to the log file Chapter6 Tuning for High Availability 113 Tuning HADB 114 Calculating the number of locks To calculate the number oflocks needed estimate the following parameters Number of concurrent users that request session data to be stored in HADB one session record per user Maximum size of the BLOB session Persistence scope max session data size in case of session modified session and maximum number of attributes in case of modified session This requires setAttribute to be called every time the session data is modified If xisthe maximum number of concurrent users that is x session data records are present in the HADB and m yisthe session si
72. ersistence frequency Specify the persistence frequency in the Admin Console under Configurations config name Availability Service Web Container Availability Persistence frequency can be set to web method time based All else being equal time based persistence frequency provides better performance but less availability than web method persistence frequency This is because the session state is written to the persistent store HADB at the time interval specified by the reap interval default is 60 seconds If the server instance fails within that interval the session state will lose any updates since the last time the session information was written to HADB Web method With web method persistence frequency the server writes the HTTP session state to HADB before it responds to each client request This can have an impact on response time that depends on the size of the data being persisted Use this mode of persistence frequency for applications where availability is critical and some performance degradation is acceptable For more information on web method persistence frequency see Configuring Availability for the Web Container in Sun GlassFish Enterprise Server 2 1 High Availability Administration Guide Time based With time based persistence frequency the server stores session information to the persistence store at a constant interval called the reap interval You specify the reap interval under Configuratio
73. erver root domains domain name logs Naturally the volume oflog activity can impact server performance particularly in benchmarking situations Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Web Container Settings General Settings In general writing to the system log slows down performance slightly and increased disk access increasing the log level decreasing the file rotation limit or time limit also slows down the application Also make sure that any custom log handler doesn tlog to a slow device like a network file system since this can adversely affect performance Log Levels Set thelog level for the server and its subsystems in the Admin Console Logger Settings page Log Levels tab The page enables you to specify the default log level for the server labeled Root the default log level for javax enterprise system subsystems labeled Server such as the EJB Container MDB Container Web Container Classloader JNDI naming system and Security and for each individual subsystem Log levels vary from FINEST which provides maximum log information through SEVERE which logs only events that interfere with normal program execution The default log level is INFO The individual subsystem log level overrides the Server setting which in turn overrides the Root setting For example the MDB container can produce log messages at a different level than server default To get more debug messages se
74. ervice from the View dropdown With this command Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Transaction Service Settings asadmin get m serverInstance transaction service The following statistics are gathered on the transaction service total tx completed Completed transactions total tx rolled back Total rolled back transactions total tx inflight Total inflight active transactions isFrozen Whether transaction system is frozen true or false inflight tx List of inflight active transactions Here is a sample ofthe output using asadmin ROBE Stats for JTS RRR total tx completed 244283 total tx rolled back 2640 total tx inflight 702 isFrozen False inflight tx Transaction Id Status ElapsedTime msec 000000000003C95A 00 Active 999 Tuning the Transaction Service This property can be used to disable the transaction logging where the performance is of utmost importance more than the recovery This property by default won t exist in the server configuration Disable Distributed Transaction Logging To disable distributed transaction logging with the Admin Console go to Configurations gt config name Transaction Service Click on Add Property and specify Name disable distributed transaction logging Value true You can also set this property with asadmin for example asadmin set serverl transaction service disable distributed transaction logging tr
75. essible from standalone client applications as well as servlets Based on the application architecture the server administrator can employ the Application Server in multiple tiers or simply host both the presentation and business logic on a single tier It is important to understand the application architecture before designing a new Application Server deployment and when deploying a new business application to an existing application server deployment Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Understanding Operational Requirements Security Requirements Most business applications require security This section discusses security considerations and decisions User Authentication and Authorization Application users must be authenticated The Application Server provides three different choices for user authentication file based LDAP and Solaris The default file based security realm is suitable for developer environments where new applications are developed and tested At deployment time the server administrator can choose between the Lighweight Directory Access Protocol LDAP or Solaris security realms Many large enterprises use LDAP based directory servers to maintain employee and customer profiles Small to medium enterprises that do not already use a directory server may find it advantageous to leverage investment in Solaris security infrastructure For more information on security realms
76. ethod ofa read only bean once The container makes multiple copies of the EJB component from that data and since the beans do not update the database the container never calls the ejbStore method This greatly reduces database traffic for these beans If there is a bean that never updates the database use a read only bean in its place to improve performance A read only bean is appropriate if either Chapter2 Tuning Your Application 43 EJB Performance Tuning 44 Database rows represented by the bean do not change The application can tolerate using out of date values for the bean For example an application might use a read only bean to represent a list of best seller books Although the list might change occasionally in the database say from another bean entirely the change need not be reflected immediately in an application The ejbLoad method of a read only bean is handled differently for CMP and BMP beans For CMP beans the EJB container calls ejbLoad only once to load the data from the database subsequent uses of the bean just copy that data For BMP beans the EJB container calls ejbLoad the first time a bean is used in a transaction Subsequent uses of that bean within the transaction use the same values The container calls ejbLoad for a BMP bean that doesn t run within a transaction every time the bean is used Therefore read only BMP beans still make a number of calls to the database To create a read
77. fresh period read only beans 44 56 remote vs local interfaces 37 removal selection policy 56 removal timeout 56 request processing settings 64 Request Timeout HTTP Service 65 resize quantity EJB cache 56 EJB pool 54 restart recovery 60 rlim fd cur 95 rlim fd max 95 104 S safety margins 24 Secure Sockets Layer 21 security considerations 21 security manager 31 semaphores 116 separate disks 107 109 multiple data devices 107 serialization 27 29 75 76 servertuning 49 servlets 29 results caching 31 tuning 29 31 session persistence frequency 117 persistence scope 118 size 118 state storing 107 126 Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Index session Continued timeout 51 Small Medium File Size HTTP file cache 68 SOAP attachments 29 Solaris JDK 85 TCP IP settings 95 tuning for performance benchmarking 104 version9 31 sq max size 95 104 SSL 21 startoptions 105 106 stateful session beans 42 43 119 stateless session beans 43 storing persistent session state 107 StringBuffer 27 28 Strings 27 28 sun rmi dgc client gcInterval 87 Survivor Ratio Sizing 89 synchronizing code 29 System gc 87 T Table Name JDBC Connection Pool 80 tcp close wait interval 95 tcp conn hash size 96 tcp conn req max q 96 104 tcp conn req max q0 96 104 tcp cwnd max 104 tcp ip abort interval 96 104 TCP IP settings 95 102 103 tcp keep
78. g 104 10 Examples EXAMPLE 4 1 EXAMPLE 4 2 Heap Configuration on Solaris Heap Configuration on Windows 12 Preface The Performance Tuning Guide describes how to get the best performance with Enterprise Server This preface contains information about and conventions for the entire Sun GlassFish Enterprise Server documentation set Sun GlassFish Enterprise Server Documentation Set TABLEP 1 Books in the Enterprise Server Documentation Set Book Title Description Documentation Center Enterprise Server documentation topics organized by task and subject Release Notes Late breaking information about the software and the documentation Includes a comprehensive table based summary of the supported hardware operating system Java Development Kit JDK and database drivers Quick Start Guide How to get started with the Enterprise Server product Installation Guide Installing the software and its components Application Deployment Guide Deployment of applications and application components to the Enterprise Server Includes information about deployment descriptors Developers Guide Creating and implementing Java Platform Enterprise Edition Java EE platform applications intended to run on the Enterprise Server that follow the open Java standards model for Java EE components and APIs Includes information about developer tools security debugging and creating lif
79. goureusement interdites LA DOCUMENTATION EST FOURNIE EN L ETAT ET TOUTES AUTRES CONDITIONS DECLARATIONS ET GARANTIES EXPRESSES OU TACITES SONT FORMELLEMENT EXCLUES DANS LA MESURE AUTORISEE PARLA LOI APPLICABLE Y COMPRIS NOTAMMENT TOUTE GARANTIE IMPLICITE RELATIVE A LA QUALITE MARCHANDE A L APTITUDE A UNE UTILISATION PARTICULIERE OU A L ABSENCE DE CONTREFACON 0903040021990 Contents Pr face E RE da M Nana ane t 13 Overview of Enterprise Server Performance Tuning see 17 Process Overview Y Performance Tuning S QU nc issues 18 Understanding Operational Requirements sn 19 Application Architect re asset E ERU dee eta dite 19 Security Requirements 2g acea e pea ein t nn sat SERES SERRA Ge HEX A nn tt 21 Hardware Re O fCes i2 dece eda p DR nn 22 Administration ee eden re ire e edo tubular i e fe iiid ria 23 General Tuning Concepts 25 5 ote estin RO HERI PAD dudit 23 Capacity Planning User Expectations Further Information s anota dote dote die epe dade EN Ua Tuning Your Application sss tnter nettes Java Programming Guidelines Avoid Serialization and Deserialization EJB Periormance Tuning actas uet avete e teet qtii bl f Ca stiatas 32 Gals M 32 Monitoring EJB Components ss General Guidelines Using Local and Remote Interfaces Improving Performance of EJB Transactions ssenarisi
80. gs When passing in any ofthe mandated Java type mappings appropriate for the attachments MIME type as an argument for the web service the JAX RPC runtime handles these as SOAP attachments For example to send out an image gif attachment use java awt Image or create a DataHandler wrapper over your image The advantages of using the wrapper are Reduced coding You can reuse generic attachment code to handle the attachments because the DataHandler determines the content type ofthe contained data automatically This feature is especially useful when using a document style service Since the content is known at runtime there is no need to make calls to attachment setContent stringContent image gif for example Improved Performance Informal tests have shown that using DataHandler wrappers doubles throughput for inage gif MIME types and multiplies throughput by approximately 1 5 for text xml or java awt Image for image types Java Server Page and Servlet Tuning Many applications running on the Enterprise Server use servlets or JavaServer Pages JSP technology in the presentation tier This section describes how to improve performance of such applications both through coding practices and through deployment and configuration settings Chapter2 Tuning Your Application 29 Java Server Page and Servlet Tuning 30 Suggested Coding Practices This section provides some tips on coding practices that improve servlet a
81. he Idle Maximum time that a stateful session bean or entity bean is allowed to be idle in the cache After this time Timeout the bean is passivated to the backup store The default value is 600 seconds The corresponding EJB deployment descriptor attribute is cache idle timeout in seconds Refresh period Rate at which a read only bean is refreshed from the data source Zero 0 means that the bean is never refreshed The default is 600 seconds The corresponding EJB deployment descriptor attribute is refresh period in seconds Note this setting does not have a custom field in the Admin Console To set it use the Add Property button in the Additional Properties section Pool and Cache Settings for Individual EJB Components Individual EJB pool and cache settings in the sun ejb jar xml deployment descriptor override those ofthe EJB container The following table lists the cache and pool settings for each type of EJB component TABLE3 2 EJB Cache and Pool Settings Cache Settings Pool Settings cache idle refresh cache timeout removal victim period pool max pool idle Type of resize max cache in timeout in selection in steady resize pool timeout in Bean quantity size seconds seconds policy seconds pool size quantity size seconds Stateful X X X X X Session Stateless X X X X Session 56 Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Refresh period TABLE3 2 EJB Cache and Pool Settings Continued
82. he Java virtual machine use the Admin Console and set the property under config name gt JVM settings JVM options Tuning the Java Heap This section discusses topics related to tuning the Java Heap for performance Guidelines for Java Heap Sizing on page 87 Heap Tuning Parameters on page 88 Guidelines for Java Heap Sizing Maximum heap size depends on maximum address space per process The following table shows the maximum per process address values for various platforms TABLE4 1 Maximum Address Space Per Process Operating System Maximum Address Space Per Process Redhat Linux 32 bit 2GB Redhat Linux 64 bit 3GB Windows 98 2000 NT Me XP 2GB Solaris x86 32 bit 4GB Solaris 32 bit 4GB Solaris 64 bit Terabytes Maximum heap space is always smaller than maximum address space per process because the process also needs space for stack libraries and so on To determine the maximum heap space that can be allocated use a profiling tool to examine the way memory is used Gauge the maximum stack space the process uses and the amount of memory taken up libraries and other Chapter4 Tuning the Java Runtime System 87 Managing Memory and Garbage Collection 88 memory structures The difference between the maximum address space and the total of those values is the amount of memory that can be allocated to the heap You can improve performance by increasing your heap size or using a differen
83. hen you declare constants as static final variables Avoid Finalizers Adding finalizers to code makes the garbage collector more expensive and unpredictable The virtual machine does not guarantee the time at which finalizers are run Finalizers may not always be executed before the program exits Releasing critical resources in finalize methods may lead to unpredictable application behavior Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Java Server Page and Servlet Tuning Declare Method Arguments final Declare method arguments final if they are not modified in the method In general declare all variables final ifthey are not modified after being initialized or set to some value Synchronize Only When Necessary Do not synchronize code blocks or methods unless synchronization is required Keep synchronized blocks or methods as short as possible to avoid scalability bottlenecks Use the Java Collections Framework for unsynchronized data structures instead of more expensive alternatives such asjava util HashTable Use DataHandlers for SOAP Attachments Usinga javax activation DataHandler for a SOAP attachment will improve performance JAX RPC specifies A mapping of certain MIME types to Java types Any MIME type is mappable to a javax activation DataHandler Asa result send an attachment gif or XML document as a SOAP attachment to an RPC style web service by utilizing the Java type mappin
84. hread idle thread timeout in seconds pool Chapter3 Tuning the Enterprise Server 71 ORB Settings TABLE3 3 Tunable ORB Settings Continued RMI IIOP from ORB to Enterprise Server communication steady thread pool size max thread pool size infrastructure thread idle thread timeout in seconds pool RMI IIOP from a vendor ORB parts ofcommunication steady thread pool size max thread pool size infrastructure thread idle thread timeout in seconds pool In process thread pool steady thread pool size max thread pool size idle thread timeout in seconds 72 Tunable ORB Parameters Tune the following ORB parameters using the Admin Console Thread Pool ID Name ofthe thread pool to use Max Message Fragment Size Messages larger than this number of bytes will be fragmented In CORBA GIOPv1 2 a Request Reply LocateRequest and LocateReply message can be broken into multiple fragments The first message is a regular Request or Reply message with more fragments bit in the flags field set to true If inter ORB messages are for the most part larger than the default size 1024 bytes increase the fragment size to decrease latencies on the network Total Connections Maximum number of incoming connections at any time on all listeners Protects the server state by allowing finite number of connections This value equals the maximum number of threads that will actively read from the connection IIOPCli
85. idled for longer than the timeout are candidates for removal When the pool size reaches the initial and minimum pool size removal of connections stops The following table summarizes pros and cons to consider when sizing connection pools TABLE3 4 Connection PoolSizing Connection pool Pros Cons Small Connection pool Faster access on the connection table May not have enough connections to satisfy requests Requests may spend more time in the queue Large Connection pool queue More connections to fulfill requests Requests will spend less or no time in the Slower access on the connection table 78 Timeout Settings There are two timeout settings MaxWait Time Amount oftime the caller the code requesting a connection will wait before getting a connection timeout The default is 60 seconds A value of zero forces caller to wait indefinitely To improve performance set Max Wait Time to zero 0 This essentially blocks the caller thread until a connection becomes available Also this allows the server to alleviate the task of tracking the elapsed wait time for each request and increases performance Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Pool Resize Quantity Idle Timeout Maximum time in seconds that a connection can remain idle in the pool After this time the pool can close this connection This property does not control connectio
86. ids ejbAcivate and ejbPassivate calls So in most cases it performs better than option C since it avoids some overhead in acquiring and releasing objects back to pool However there are some cases where option C can provide better performance If the beans in the cache are rarely reused and if beans are constantly added to the cache then it makes no sense to cache beans With option C is used the container puts beans back into the pool instead of caching them after method invocation or on transaction completion This option reuses instances better and reduces the number of live objects in the JVM speeding garbage collection Determining the best commit option To determine whether to use commit option B or commit option C first take a look at the cache hits value using the monitoring command for the bean If the cache hits are much higher Chapter3 Tuning the Enterprise Server 57 Java Message Service Settings than cache misses then option B is an appropriate choice You might still have to change the max cache size and cache resize quantity to get the best result Ifthe cache hits are too low and cache misses are very high then the application is not reusing the bean instances and hence increasing the cache size using max cache size will not help assuming that the access pattern remains the same In this case you might use commit option C If there is no great difference between cache hits and cache misses then tune max
87. ilability Itis important to pay attention while determining the HTTP session size If you are creating large HTTP session objects calculate the HADB nodes as discussed in Tuning HADP on page 107 Checkpointing Stateful Session Beans Checkpointing saves a stateful session bean SFSB state to the HADB so that if the server instance fails the SFSB is failed over to another instance in the cluster and the bean state recovered The size ofthe data being checkpointed and the frequency at which checkpointing happens determine the additional overhead in response time for a given client interaction You can enable SFSB checkpointing at numerous different levels For the entire server instance or EJB container For the entire application Fora specific EJB module Per method in an individual EJB module For best performance specify checkpointing only for methods that alter the bean state significantly by adding the lt checkpointed methods gt tag in the sun ejb jar xmt file Configuring the JDBC Connection Pool The Enterprise Server uses JDBC to store and retrieve HADB data For best performance configure the JDBC connection pool for the fastest possible HADB read write operations Configure the JDBC connection pool in the Admin Console under Resources gt JDBC gt Connection Pools gt pool name The connection pool configuration settings are Initial and Minimum Pool Size Minimum and initial number of connections maint
88. ile there may be several million registered customers for an online business at any one time only a Chapter 1 Overview of Enterprise Server Performance Tuning 25 Further Information fraction of them are logged in and performing business transactions common mistake during capacity planning is to use the total size of customer population as the basis and not the average and peak numbers for concurrent users The number of concurrent users also may exhibit patterns over time What is the average and peak amount of data transferred per request This value is also application specific Good estimates for content size combined with other usage patterns will help you anticipate network capacity needs What is the expected growth in user load over the next year Planning ahead for the future will help avoid crisis situations and system downtimes for upgrades Further Information 26 For more information on Java performance see Java Performance Documentation and Java Performance BluePrints For details on optimizing EJB components see Seven Rules for Optimizing Entity Beans For details on profiling see Profiling Tools in Sun GlassFish Enterprise Server 2 1 Developers Guide For more details on the domain xml file see Sun GlassFish Enterprise Server 2 1 Administration Reference Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 CHAPTER 2 Tuning Your Application This chapter provide
89. ility sssseeeeeenteente nente 107 Tuning HADB Disk USE e t Memory AllOCatON SERRE tentata teo ledit Naren i dente di edes 109 Performance NM 110 Operating System Configuration sise 116 Tuning the Enterprise Server for High Availability see 116 Tuning Session Persistence Frequency Session Persistence SCOPE nm ni io o EE GEEHRTE tesa deity SESSION SIZE P M Checkpointing Stateful Session Beans sienne Configuring the JDBC Connection Pool sise 119 Configuring the Load Balancer sao d sone bete trop i adeb d ianiai te eiie 120 Enabling the Health Checker uite tette better deus 120 INR nt AA INDEM LIN nan nana 123 Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Figures FIGURE 1 1 Java EE Application Model Tables TABLE 1 1 TABLE 1 2 TABLE 3 1 TABLE 3 2 TABLE 3 3 TABLE 3 4 TABLE 4 1 TABLE 5 1 TABLE 5 2 P rformance Tuning Roadmap sine dunes 17 Factors That Affect Performance uiae cas ene ec tap ae reddens 24 Bean Type Pooling or Caching thoi nude 53 EJB Cache and Pool Settings ethnies 56 Tanabe ORBSettings aodio en oe nn en Oe iU IU PU IUD 71 Connection Pool Sizing sine 78 Maximum Address Space Per Process nn 87 Tuning Parameters for Solaris muri dade teintentelee dei men seat edet i 95 Tuning 64 bit Systems for Performance Benchmarkin
90. ime of bean creation on the request path Stateless session beans and entity beans use the EJB pool Keeping in mind how you use stateless session beans and the amount of traffic your server handles tune the pool size to prevent excessive creation and deletion of beans EJB Pool Settings An individual EJB component can specify cache settings that override those of the EJB container in the bean pool element of the EJB components sun ejb jar xml deployment descriptor The EJB pool settings are Initial and Minimum Pool Size the initial and minimum number of beans maintained in the pool Valid values are from 0 to MAX INTEGER and the default value is 8 The corresponding EJB deployment descriptor attribute is steady pool size Set this property to a number greater than zero for a moderately loaded system Having a value greater than zero ensures that there is always a pooled instance to process an incoming request Maximum Pool Size the maximum number of connections that can be created to satisfy client requests Valid values are from zero to MAX INTEGER and the default is 32 A value of zero means that the size of the pool is unbounded The potential implication is that the JVM heap will be filled with objects in the pool The corresponding EJB deployment descriptor attribute is max pool size Set this property to be representative of the anticipated high load of the system An very large pool wastes memory and can slow dow
91. in createFromStream message construction complete com sun corba ee internal iiop MessageMediator Thread ORB Client side Reader conn to 192 18 80 118 1050 5 main Received message T Input Buffer Current index 0 Total length 340 47 49 4f 50 01 02 00 04 0 0 00 01 48 00 00 00 05 GIOP bli scs Note The flag Dcom sun CORBA ORBdebug giop generates many debug messages in the logs This is used only when you suspect message fragmentation In this sample output above the createFromStreamtype is shown as 4 This implies that the message is a fragment of a bigger message To avoid fragmented messages increase the fragment size Larger fragments mean that messages are sent as one unit and not as fragments saving the overhead of multiple messages and corresponding processing at the receiving end to piece the messages together If most messages being sent in the application are fragmented increasing the fragment size is likely to improve efficiency On the other hand if only a few messages are fragmented it might be more efficient to have a lower fragment size that requires smaller buffers for writing messages Improving ORB Performance with Java Serialization Itis possible to improve ORB performance by using Java Serialization instead of standard Common Data Representation CDR for data for transport over the network This capability is called Java Serialization over GIOP General Inter ORB Protocol or JSG I
92. in Sun GlassFish Enterprise Server 2 1 Administration Guide Alternatively use the asadmin list command For more information see List 1 For statistics on stateful session bean passivations use this command asadmin get m serverInstance application appName ejb module moduleName Stateful session bean beanName bean cache From the attribute values that are returned use this command num passivationsnum passivation errorsnum passivation success General Guidelines The following guidelines can improve performance of EJB components Keep in mind that decomposing an application into many EJB components creates overhead and can degrade performance EJB components are not simply Java objects They are components with semantics for remote call interfaces security and transactions as well as properties and methods Use High Performance Beans Use high performance beans as much as possible to improve the overall performance of your application For more information see Tuning Tips for Specific Types of EJB Components on page 42 The types of EJB components are listed below from the highest performance to the lowest Stateless Session Beans and Message Driven Beans Stateful Session Beans Container Managed Persistence CMP entity beans configured as read only Bean Managed Persistence BMP entity beans configured as read only CMP beans BMP beans ON UV eco De Use Caching Caching can greatly improve performance when used w
93. ing options include m XX PrintGCDetails for more detailed logging information m Xloggc fileto save the information in a log file Other Garbage Collector Settings For applications that do not dynamically generate and load classes the size of the permanent generation has no effect on GC performance For applications that dynamically generate and load classes for example JSP applications the size of the permanent generation does affect GC performance since filling the permanent generation can trigger a Full GC Tune the maximum permanent generation with the XX MaxPermSize option Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Managing Memory and Garbage Collection Although applications can explicitly invoke GC with the System gc method doing so isa bad idea since this forces major collections and inhibits scalability on large systems It is best to disable explicit GC by using the flag XX DisableExplicitGC The Enterprise Server uses RMI in the Administration module for monitoring Garbage cannot be collected in RMI based distributed applications without occasional local collections so RMI forces a periodic full collection Control the frequency ofthese collections with the property sun rmi dgc client gcInterval For example java Dsun rmi dgc client gcInterval 3600000 specifies explicit collection once per hour instead of the default rate of once per minute To specify the attributes for t
94. isely For example Cache EJB references To avoid a JNDI lookup for every request cache EJB references in servlets Cache home interfaces Since repeated lookups to a home interface can be expensive cache references to EBBHomes in the init methods of servlets Chapter2 Tuning Your Application 35 EJB Performance Tuning 36 Cache EJB resources Use setSessionContext or ejbCreate to cache bean resources This is again an example of using bean lifecycle methods to perform application actions only once where possible Remember to release acquired resources in the ej bRemove method Use the Appropriate Stubs The stub classes needed by EJB applications are generated dynamically at runtime when an EJB client needs them This means that it is not necessary to generate the stubs or retrieve the client JAR file when deploying an application with remote EJB components When deploying an application it is no longer necessary to specify the retrieve option which can speed up deployment If you have a legacy rich client application that directly uses the CosNaming service not a recommended configuration then you must generate the stubs for your application explicitly using RMIC For more information see Sun GlassFish Enterprise Server 2 1 Troubleshooting Guidefor more details Remove Unneeded Stateful Session Beans Removing unneeded stateful session beans avoids passivating them which requires disk operations C
95. ized note that some emphasized items appear bold online A cache is a copy that is stored locally Do not save the file Symbol Conventions The following table explains symbols that might be used in this book TABLEP 4 Symbol Conventions Symbol Description Example Meaning Contains optional arguments ls 1 and command options Contains a set of choices for a required command option d y n Indicates a variable reference Joins simultaneous multiple Control A keystrokes Joins consecutive multiple Ctrl A N keystrokes com sun javaRoot The 1 option is not required The d option requires that you use either the y argument or then argument References the value of the com sun javaRoot variable Press the Control key while you press the A key Press the Control key release it and then press the subsequent keys Preface TABLEP 4 Symbol Conventions Continued Symbol Description Example Meaning gt Indicates menu item File New gt Templates From the File menu choose New selection in a graphical user From the New submenu choose interface Templates Documentation Support and Training The Sun web site provides information about the following additional resources Documentation http www sun com documentation Support http www sun com support Training http www sun com training Third Party Web Site References Third
96. k delay time of 500 ms between business method calls exchanging data of about 100 KB These settings apply to RMI IIOP clients on the Solaris OS Linux Configuration The following parameters must be added to the etc rc d rc local file that gets executed during system start up lt begin max file count updated 256 descriptors per 4Mb Specify number of file descriptors based on the amount of system RAM echo 6553 proc sys fs file max inode max 3 4 times the file max echo 262144 gt proc sys fs inode max make more local ports available echo 1024 25000 gt proc sys net ipv4 ip local port range increase the memory available with socket buffers echo 2621143 proc sys net core rmem max Chapter5 Tuning the Operating System and Platform 97 Tuning for Solaris on x86 echo 262143 gt proc sys net core rmem default above configuration for 2 4 X kernels echo 4096 131072 262143 gt proc sys net ipv4 tcp rmem echo 4096 13107262143 gt proc sys net ipv4 tcp wmem disable RFC2018 TCP Selective Acknowledgements and RFC1323 TCP timestamps echo 0 proc sys net ipv4 tcp sack echo 0 proc sys net ipv4 tcp timestamps double maximum amount of memory allocated to shm at runtime echo 67108864 proc sys kernel shmmax improve virtual memory VM subsystem of the Linux echo 100 1200 128 512 15 5000 500 1884 2 gt proc sys vm bdflush we also do a sysctl sysctl p etc sysctl conf end
97. lly provides a sense of the vertical scalability characteristics of the system Be sure to properly tune the application Application Server backend database resources and operating system so that they do not skew the results 3 Determine horizontal scalability If sufficiently powerful hardware resources are available a single hardware node may meet the performance requirements However for better availability you can cluster two or more systems Employing external load balancers and workload simulation determine the performance benefits of replicating one well tuned application server node as determined in step 2 User Expectations Application end users generally have some performance expectations Often you can numerically quantify them To ensure that customer needs are met you must understand these expectations clearly and use them in capacity planning Consider the following questions regarding performance expectations What do users expect the average response times to be for various interactions with the application What are the most frequent interactions Are there any extremely time critical interactions What is the length of each transaction including think time In many cases you may need to perform empirical user studies to get good estimates What are the anticipated steady state and peak user loads Are there are any particular times ofthe day week or year when you observe or expect to observe load peaks Wh
98. lush fputs took too long To avoid this problem keep the HADB executable files and the history files on physical disks different from those of the data devices Memory Allocation Itis essential to allocate sufficient memory for HADB especially when it is co located with other processes The HADB Node Supervisor Process NSUP tracks the time elapsed since the last time it performed monitoring If the time exceeds a specified maximum 2500 ms by default NSUP restarts the node The situation is likely when there are other processes in the system that compete for memory causing swapping and multiple page faults When the blocked node restarts all active transactions on that node are aborted If Enterprise Server throughput slows and requests abort or time out make sure that swapping is notthe cause To monitor swapping activity on Unix systems use this command vmstat S In addition look for this message in the HADB history files It is written when the HADB node is restarted where M is greater than N Process blocked for M sec max block time is N sec The presence of aborted transactions will be signaled by the error message HADB00224 Transaction timed out or HADB00208 Transaction aborted Chapter6 Tuning for High Availability 109 Tuning HADB 110 Performance For best performance all HADB processes clu xxx srv must fit in physical memory They should not be paged or swapped The same applies for shared
99. more information see Thread Pool Sizing on page 74 Client ORB Properties Specify the following properties as command line arguments when launching the client program You do this by using the following syntax when starting the Java VM Dproperty value Controlling connections between client and server ORB When using the default JDK ORB on the client a connection is established from the client ORB to the application server ORB every time an initial context is created To pool or share these connections when they are opened from the same process by adding to the configuration on the client ORB Djava naming factory initial com sun appserv naming S1ASCtxFactory Using multiple connections Note The property com sun appserv iiop orbconnections is not supported in Sun GlassFish Enterprise Server version 8 x When using the context factory com sun appserv naming S1ASCtxFactory you can specify the number of connections to open to the server from the client ORB with the property com sun appserv iiop orbconnections The default value is one Using more than one connection may improve throughput for network intense applications The configuration changes are specified on the client ORB s by adding the following jvm options Djava naming factory initial com sun appserv naming S1ASCtxFactory Dcom sun appserv iiop orbconnections value Chapter 3 Tuning the Enterprise Server 73 ORB Settings 74 Load Balancing For
100. mp field mapping gt lt cmr field mapping gt lt cmr field name gt orderLines lt cmr field name gt lt column pair gt lt column name gt 0rderTable OrderID lt column name gt lt column name gt OrderLineTable OrderLine OrderID lt column name gt lt column pair gt lt fetched with gt default fetched with cmr field mapping entity mappping Now when an Order is retrieved the CMP engine issues SOL to retrieve all related OrderLines with a SELECT statement that has the following WHERE clause OrderTable OrderID OrderLineTable OrderLine OrderID This clause indicates an outer join These OrderLines are pre fetched Chapter2 Tuning Your Application 45 EJB Performance Tuning 46 Pre fetching generally improves performance because it reduces the number of database accesses However if the business logic often uses Orders without referencing their OrderLines then this can have a performance penalty that is the system has spent the effort to pre fetch the OrderLines that are not actually needed Avoid pre fetching for specific finder methods this can often avoid that penalty For example consider an order bean has two finder methods a findByPrimaryKey method that uses the orderlines and a findByCustomerId method that returns only order information and hence doesn t use the orderlines If you ve enabled CMR pre fetching for the orderlines both finder methods will pre fetch the orderlines However yo
101. ms It is important to remember that EJB local interfaces do not use the ORB Using a local interface passes all arguments by reference and does not require copying any objects How a Client Connects to the ORB A rich client Java program performs a new initialContext call which creates a client side ORB instance This in turn creates a socket connection to the Enterprise Server IIOP port The reader thread is started on the server ORB to service IIOP requests from this client Using the initialContext the client code does a lookup of an EJB deployed on the server An IOR which is a remote reference to the deployed EJB on the server is returned to the client Using this object reference the client code invokes remote methods on the EJB InitialContext lookup for the bean and the method invocations translate the marshalling application request data in Java into IIOP message s that are sent on the socket connection that was created earlier on to the server ORB The server then creates a response and sends it back on the same connection This data in the response is then un marshalled by the client ORB and given back to the client code for processing The Client ORB shuts down and closes the connection when the rich client application exits Monitoring the ORB ORB statistics are disabled by default To gather ORB statistics enable monitoring with this asadmin command Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 200
102. n some cases JSG can provide better performance throughput than CDR The performance differences depend highly on the application Applications with remote objects having small amounts data transmitted between client and server will most often perform better using JSG Chapter3 Tuning the Enterprise Server 75 Thread Pool Settings v To Enable Java Serialization You must set this property on all servers that you want to use JSG Inthe tree component expand the Configurations node Expand the desired node Select the JVM Settings node In the JVM Settings page choose the JVM Options tab Click Add JVM Option and enter the following value Dcom sun CORBA encoding ORBEnableJavaSerialization true Click Save Restart the Application Server Using JSG for Application Clients If an application uses standalone non web clients application clients and you want to use JSG you must also set a system property for the client applications A common way to do this is to add the property to the Java command line used to start the client application for example java Dcom sun CORBA encoding ORBEnableJavaSerialization true Dorg omg CORBA ORBInitialHost gollum Dorg omg CORBA ORBInitialPort 35309 MyClientProgram Thread Pool Settings 76 You can both monitor and tune thread pool settings through the Admin Console To configure monitoring with the Admin Console open the page Configurations gt config name gt Monitoring To
103. n stop increasing the settings The following HTTP keep alive settings affect performance Thread Count m Max Connections Time Out Keep Alive Query Mean Time Keep Alive Query Max Sleep Time Max Connections Max Connections controls the number of requests that a particular client can make over a keep alive connection The range is any positive integer and the default is 256 Adjust this value based on the number of requests a typical client makes in your application For best performance specify quite a large number allowing clients to make many requests The number of connections specified by Max Connections is divided equally among the keep alive threads If Max Connections is not equally divisible by Thread Count the server can allow slightly more than Max Connections simultaneous keep alive connections Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 HTTP Service Settings Time Out Time Out determines the maximum time in seconds that the server holds open an HTTP keep alive connection A client can keep a connection to the server open so that multiple requests to one server can be serviced by a single network connection Since the number ofopen connections that the server can handle is limited a high number of open connections will prevent new clients from connecting The default time out value is 30 seconds Thus by default the server will close the connection if idle for more
104. n the system A very small pool is also inefficient due to contention Pool Resize Quantity the number of beans to be created or deleted when the cache is being serviced by the server Valid values are from zero to MAX INTEGER and default is 16 The corresponding EJB deployment descriptor attribute is resize quantity Besure to re calibrate the pool resize quantity when you change the maximum pool size to maintain an equilibrium Generally a larger maximum pool size should have a larger pool resize quantity Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 EJB Container Settings Pool Idle Timeout the maximum time that a stateless session bean entity bean or message driven bean is allowed to be idle in the pool After this time the bean is destroyed if the bean in case is a stateless session bean or a message driver bean This is a hint to server The default value is 600 seconds The corresponding EJB deployment descriptor attribute is pool idle timeout in seconds If there are more beans in the pool than the maximum pool size the pool drains back to initial and minimum pool size in steps of pool resize quantity at an interval specified by the pool idle timeout Ifthe resize quantity is too small and the idle timeout large you will not see the pool draining back to steady size quickly enough Tuning the EJB Cache A bean in the cache represents the ready state in the EJB lifecycle This means that
105. n timeouts on the database server Keep this timeout shorter than the database server timeout if such timeouts are configured on the database to prevent accumulation of unusable connection in Enterprise Server For best performance set Idle Timeout to zero 0 seconds so that idle connections will not be removed This ensures that there is normally no penalty in creating new connections and disables the idle monitor thread However there is a risk that the database server will reset a connection that is unused for too long Isolation Level Settings Two settings control the connection pool transaction isolation level on the database server Transaction Isolation Level specifies the transaction isolation level of the pooled database connections If this parameter is unspecified the pool uses the default isolation level provided by the JDBC Driver Isolation Level Guaranteed Guarantees that every connection obtained from the pool has the isolation specified by the Transaction Isolation Level parameter Applicable only when the Transaction Isolation Level is specified The default value is true This setting can have some performance impact on some JDBC drivers Set to false when certain that the application does not change the isolation level before returning the connection Avoid specifying Transaction Isolation Level If that is not possible consider setting Isolation Level Guaranteed to false and make sure applications do not
106. nd JSP application performance General Guidelines Follow these general guidelines to increase performance of the presentation tier Minimize Java synchronization in servlets Don t use the single thread model for servlets Use the servlet s init method to perform expensive one time initialization Avoid using System out println calls Avoid Shared Modified Class Variables In the servlet multithread model the default a single instance of a servlet is created for each application server instance All requests for a servlet on that application instance share the same servlet instance This can lead to thread contention if there are synchronization blocks in the servlet code So avoid using shared modified class variables since they create the need for synchronization HTTP Session Handling Follow these guidelines when using HTTP sessions m Create sessions sparingly Session creation is not free If a session is not required do not create one Use javax servlet http HttpSession invalidate to release sessions when they are no longer needed m Keep session size small to reduce response times If possible keep session size below seven KB Use the directive lt page session false gt in JSP files to prevent the Enterprise Server from automatically creating sessions when they are not necessary Avoid large object graphs in an HttpSession They force serialization and add computational overhead
107. ndd dev tcp 240000 60000 Set on clients too tcp time wait interval ndd dev tcp 240000 60000 Set on clients too Chapter5 Tuning the Operating System and Platform 95 Tuning for the Solaris OS TABLE5 1 Tuning Parameters for Solaris Continued Parameter Scope Default Tuned Value Comments tcp conn req max q ndd dev tcp 128 1024 tcp conn req max q ndd dev tcp 1024 4096 tcp ip abort interval ndd dev tcp 480000 60000 tcp keepalive interval ndd dev tcp 7200000 900000 For high traffic web sites lower this value tcp rexmit interval initial ndd dev tcp 3000 3000 If retransmission is greater than 30 4096 you should increase this value tcp rexmit interval max ndd dev tcp 240000 10000 tcp rexmit interval min ndd dev tcp 200 3000 tcp smallest anon port ndd dev tcp 32768 1024 Set on clients too tcp slow start initial ndd dev tcp 1 2 Slightly faster transmission of small amounts of data tcp xmit hiwat ndd dev tcp 8129 32768 Size of transmit buffer tcp recv hiwat ndd dev tcp 8129 32768 Size of receive buffer tcp conn hash size ndd dev tcp 512 8192 Size of connection hash table See Sizing the Connection Hash Table on page 96 Sizing the Connection Hash Table The connection hash table keeps all the information for active TCP connections Use the following command to get the size of the connection hash table ndd get dev tcp tcp conn hash
108. nefit applies to transaction intensive tests Gains in real applications may be less Keypoint Interval The keypoint interval determines how often entries for completed transactions are removed from the log file Keypointing prevents a process log from growing indefinitely Frequent keypointing is detrimental to performance The default value of the Keypoint Interval is 2048 which is sufficient in most cases HTTP Service Settings 60 Monitoring and tuning the HTTP server instances that handle client requests are important parts of ensuring peak Enterprise Server performance Monitoring the HTTP Service on page 60 Tuning the HTTP Service on page 64 Tuning HTTP Listener Settings on page 69 Monitoring the HTTP Service Enable monitoring statistics for the HTTP service using either Admin Console or asadmin In the Admin Console the monitoring level LOW or HIGH has no effect on monitoring the HTTP Service Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 HTTP Service Settings With asadmin use the following command to list the monitoring parameters available list user admin port 4848 m server instance name http service where server instance name is the name of the server instance Use the following command to get the values get user admin port 4848 m server http service parameter name where parameter name is the name ofthe parameter to monitor Statistics colle
109. ni 38 Using Special Techniques i indie osten stent eee eet stone love e fecit erene 39 Contents Tuning Tips for Specific Types of EJB Components sun 42 JDBC and Database ACCESS sue te na Er le Nestl dise d c tete 46 Tuning Message Driven Beans sse eene enne nennen 47 3 Tuning the Enterprise Server 49 D ploymenbtSetifBgs ciao dincinad amiorutan ccn dede cisci ea ii iei ad Di ri EI eine 49 Disable A to deploymetit Ji itte iaiia 50 Use Pr compil d JavaServer Pages un Minna nanas 50 Disable Dynamic Application Reloading sun 50 Logger Settings 50 General Settings EL a E A A E tester ced as certe 51 Log Leyo e 51 Web Container Settings 5 DR Dn DIE REI LEUR ORO RID RI Ue LOEO RI DU LIRE 51 Session Properties Session LIM OUE 1 e ecrire irte ir niani ees torta i 51 Manager Properties Reap Interval sienne 52 Disable Dynamic JSP Reloading EJB Container Settings sisi Monitoring the EJB Container sirsie e tete n anne Tuning the EJB Container oe etae ee ananas 53 Java Message Service Settings sise Transaction Service Settings sense qud i derat Qu er d a dr i a I deed Monitoring the Transaction Service Tuning the Transaction Service cec t eee t feit ce e i ri sU ea dits HELP Service STONES cissssciecsesscssiancsesssaevsegeviersecsegstacssegssacvesgetsesacesegetacasesscaccdeasesscacesegetaseegs cacedeasdesea Monitoring th HTTP STI nucis nen
110. ns gt config name gt Web Container Manager Properties where config name is the name of the configuration By default the reap interval is 60 seconds Every time the reap interval elapses a special thread wakes up iterates over all the sessions in memory and saves the session data In general time based persistence frequency will yield better performance than web method since the server s responses to clients are not held back by saving session information to the HADB Use this mode of persistence frequency when performance is more important than availability Chapter 6 Tuning for High Availability 117 Tuning the Enterprise Server for High Availability 118 Session Persistence Scope You can specify the scope ofthe persistence in addition to persistence frequency on the same page in the Admin Console where you specify persistence frequency Configurations gt config name gt Availability Service Web Container Availability For detailed description of different persistence scopes see Chapter 7 Configuring High Availability Session Persistence and Failover in Sun GlassFish Enterprise Server 2 1 High Availability Administration Guide Persistence scope can be one of m session modifed session modified attribute session With the session persistence scope the server writes the entire session data to HADB regardless of whether it has been modified This mode ensures that the session data in the back
111. ntervals you could set the maximum age to 21600 seconds 6 hours Otherwise consider setting the maximum age to the longest time you are willing to serve the previous version ofa content file after the file has been modified Small Medium File Size and File Size Limit The cache treats small medium and large files differently The contents of medium files are cached by mapping the file into virtual memory Unix Linux platforms The contents of small files are cached by allocating heap space and reading the file into it The contents of large files are not cached although information about large files is cached The advantage of distinguishing between small files and medium files is to avoid wasting part of many pages of virtual memory when there are lots of small files So the Small File Size Limit is typically a slightly lower value than the VM page size File Transmission When File Transmission is enabled the server caches open file descriptors for files in the file cache rather than the file contents Also the distinction normally made between small medium and large files no longer applies since only the open file descriptor is being cached By default File Transmission is enabled on Windows and disabled on UNIX On UNIX only enable File Transmission for platforms that have the requisite native OS support HP UX and AIX Don t enable it for other UNIX Linux platforms Sun GlassFish Enterprise Server 2 1 Performance Tuning Guid
112. o checked to disk a separate log device at regular intervals The page size of this buffer and the associated data device is 4096 bytes Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Tuning HADB Large BLOBs necessarily allocate many disk blocks and thus create a high load on the node internal log This is normally not a problem since each entry in the nilog is small Tuning InternalLogbufferSize Begin with the default value Look out for HIGH LOAD informational messages in the history files The relevant messages contain nilog and a description ofthe internal resource contention that occurred Use the following command to display node internal log buffer information hadbm resourceinfo nilogbuf For example the output might look something like this Node No Avail Free Size 0 11 11 1 11 11 To change the size ofthe nilog buffer use the following command hadbm set InternalLogbufferSize The hadbm restarts all the nodes one by one for the change to take effect For more information on using this command see Configuring HADB in Sun GlassFish Enterprise Server 2 1 High Availability Administration Guide Note If the size ofthe nilog buffer is changed the associated log device located in the same directory as the data devices also changes The size ofthe internallog buffer must be equal to the size of the internal log device The command hadbm set InternalLogBufferSize ensures this r
113. o specifically close the session or it will stay open which ties up resources Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 CHAPTER 3 Tuning the Enterprise Server This chapter describes some ways to tune the Enterprise Server for optimum performance including the following topics Deployment Settings on page 49 Logger Settings on page 50 Web Container Settings on page 51 EJB Container Settings on page 53 Java Message Service Settings on page 58 Transaction Service Settings on page 58 HTTP Service Settings on page 60 ORB Settings on page 70 Thread Pool Settings on page 76 Resources JDBC Connection Pool Settings on page 77 Connector Connection Pool Settings on page 80 Deployment Settings Deployment settings can have significant impact on performance Follow these guidelines when configuring deployment settings for best performance Disable Auto deployment on page 50 Use Pre compiled JavaServer Pages on page 50 Disable Dynamic Application Reloading on page 50 49 Logger Settings Disable Auto deployment Enabling auto deployment will adversely affect deployment though it is a convenience in a development environment For a production system disable auto deploy to optimize performance If auto deployment is enabled then the Reload Poll Interval setting can have a significant performance impact Dis
114. ommendations for optimal performance scaling server for the following server subsystems Processors on page 93 Memory on page 94 Disk Space on page 94 Networking on page 94 Processors The Enterprise Server automatically takes advantage of multiple CPUs In general the effectiveness of multiple CPUs varies with the operating system and the workload but more processors will generally improve dynamic content performance Static content involves mostly input output I O rather than CPU activity If the server is tuned properly increasing primary memory will increase its content caching and thus increase 93 Server Scaling 94 the relative amount oftime it spends in I O versus CPU activity Studies have shown that doubling the number of CPUs increases servlet performance by 50 to 80 percent Memory See the section Hardware and Software Requirements in the Sun Java System Application Server Release Notes for specific memory recommendations for each supported operating system Disk Space Itis best to have enough disk space for the OS document tree and log files In most cases 2GB total is sufficient Put the OS swap paging file Enterprise Server logs and document tree each on separate hard drives This way if the log files fill up the log drive the OS does not suffer Also its easy to tell if the OS paging file is causing drive activity for example OS vendors generally provide specific recommendations for h
115. oolSize 110 111 demilitarized zone DMZ 22 123 Index deployment settings 49 tips 31 deserialization 27 29 disabling networkinterrupts 105 disk configuration 105 disk I O performance 102 diskspace 94 distributed transaction logging disabling 59 DNS cache 61 62 DNS lookups 62 67 dynamic reloading disabling 50 E EJB components cache tuning 35 36 36 55 56 commit options 57 58 monitoring individual 34 35 performance of types 35 pool tuning 36 54 55 stubs using 36 transactions 38 39 EJB container 53 58 cache settings 55 56 caching vs pooling 53 54 monitoring 32 53 poolsettings 54 55 tuning 32 53 58 eliminateRedundantEndTransaction 120 encryption 21 22 entity beans 42 expectations 25 26 F file cache 63 67 68 file descriptors 99 100 File Size Limit HTTP file cacheHTTP file cache File Size Limit 68 File Transmission HTTP file cacheHTTP file cache File Transmission 68 final methods 28 finalizers avoiding 28 footprint 86 fragmented messages 75 G Garbage Collector 84 85 generational object memory 84 H HADB 107 data devicesize 107 database buffer 110 history files 108 JDBC connection pool 119 locks 113 memory 109 timeouts 115 hardware resources 22 Hash Init Size HTTP file cache 68 hash table connection 96 health checker 120 high availability database 107 hires_tick 104 history files HADB 108 HitRatio 62 HotSpot 85 HTTP acce
116. ores each chunk as a database row context row is synonymous with tuple or record in pages of 16KB There is some small memory overhead for each row approximately 30 bytes With the most compact allocation of rows BLOB chunks two rows are stored in a page Internal fragmentation can result in each page containing only one row On average 5096 of each page contains user data For availability in case of node failure HADB always replicates user data An HADB node stores its own data plus a copy of the data from its mirror node Hence all data is stored twice Since 5096 ofthe space on a node is user data on average and each node is mirrored the data devices must have space for at least four times the volume ofthe user data In the case of data refragmentation HADB keeps both the old and the new versions of a table while the refragmentation operation is running All application requests are performed on the old table while the new table is being created Assuming that the database is primarily used for one huge table containing BLOB data for session states this means the device space requirement must be multiplied by another factor oftwo Consequently if you add nodes to a running database and want to refragment the data to use all nodes you must have eight times the volume of user data available Additionally you must also account for the device space that HADB reserves for its internal use four times that of the LogBuf ferSize
117. ortant to clearly define the operational environment The operational environment is determined by high level constraints and requirements such as Application Architecture on page 19 Security Requirements on page 21 Hardware Resources on page 22 Application Architecture The Java EE Application model as shown in the following figure is very flexible allowing the application architect to split application logic functionally into many tiers The presentation layer is typically implemented using servlets and JSP technology and executes in the web container Chapter 1 Overview of Enterprise Server Performance Tuning 19 Understanding Operational Requirements Client Side Presentation Browser Pure HTML Java Applet Desktop Java Application Other Device J2EE Client Server Side Business Logic Server Side Presentation Enterprise Information System Web Server EJB Container JSP EJB Java Servlet is FIGURE 1 1 Java EE Application Model 20 Moderately complex enterprise applications can be developed entirely using servlets and JSP technology More complex business applications often use Enterprise JavaBeans EJB components The Application Server integrates the web and EJB containers in a single process Local access to EJB components from servlets is very efficient However some application deployments may require EJB components to execute in a separate process and be acc
118. ow much swap or paging space to allocate Based on Sun testing Enterprise Server performs best with swap space equal to RAM plus enough to map the document tree Networking To determine the bandwidth the application needs determine the following values The number of peak concurrent users N peak the server needs to handle The average request size on your site r The average request can include multiple documents When in doubt use the home page and all its associated files and graphics Decide how long t the average user will be willing to wait for a document at peak utilization Then the bandwidth required is Nye t For example to support a peak of 50 users with an average document size of 24 Kbytes and transferring each document in an average of 5 seconds requires 240 Kbytes 1920 Kbit s So the site needs two T1 lines each 1544 Kbit s This bandwidth also allows some overhead for growth The server s network interface card must support more than the WAN to which it is connected For example if you have up to three T1 lines you can get by with a 10BaseT interface Up to a T3 line 45 Mbit s you can use 100BaseT But if you have more than 50 Mbit s of WAN bandwidth consider configuring multiple 100BaseT interfaces or look at Gigabit Ethernet technology Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Tuning for the Solaris OS Solaris 10 Platform Specific Tuning Inform
119. party URLs are referenced in this document and provide additional related information Note Sun is not responsible for the availability of third party web sites mentioned in this document Sun does not endorse and is not responsible or liable for any content advertising products or other materials that are available on or through such sites or resources Sun will not be responsible or liable for any actual or alleged damage or loss caused or alleged to be caused by or in connection with use of or reliance on any such content goods or services that are available on or through such sites or resources Sun Welcomes Your Comments Sun is interested in improving its documentation and welcomes your comments and suggestions To share your comments go to http docs sun comand click Feedback In the online form provide the document title and part number The part number is a seven digit or nine digit number that can be found on the title page of the book or at the top of the document 16 Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 CHAPTER 1 Overview of Enterprise Server Performance Tuning You can significantly improve performance of the Sun GlassFish Enterprise Server and of applications deployed to it by adjusting a few deployment and server configuration settings However it is important to understand the environment and performance goals An optimal configuration for a production environment might
120. pool as unbounded is NOT recommended Monitoring Individual EJB Components To gather method invocation statistics for all methods in a bean use this command asadmin get m monitorableObject where monitorableObject is a fully qualified identifier from the hierarchy of objects that can be monitored shown below serverInstance application applicationName ejb module moduleName where moduleName is x_jar for module x jar m stateless session bean beanName bean pool bean method methodName m stateful session bean beanName bean cache bean method methodName entity bean beanName bean cache bean pool bean method methodName m message driven bean beanName bean pool bean method methodName methodName onMessage For standalone beans use this pattern serverInstance application applicationName standalone ejb module moduleName The possible identifiers are the same as for ejb module For example to get statistics for a method in an entity bean use this command asadmin get m serverInstance application appName ejb module moduleName entity bean beanName bean method methodName Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 EJB Performance Tuning To find the possible objects applications modules beans and methods and object attributes that can be monitored use the Admin Console For more information see Chapter 18 Monitoring Components and Services
121. programmatically alter the connections isolation level If you must specify isolation level specify the best performing level possible The isolation levels listed from best performance to worst are READ_UNCOMMITTED READ_COMMITTED REPEATABLE READ SERIALIZABLE Ben a Choose the isolation level that provides the best performance yet still meets the concurrency and consistency needs of the application Connection Validation Settings The following settings determine whether and how the pool performs connection validation Chapter 3 Tuning the Enterprise Server 79 Connection Validation Required Connection Validation Required Validation Method Table Name Close All Connections On Any Failure 80 If true the pool validates connections checks to find out if they are usable before providing them to an application If possible keep the default value false Requiring connection validation forces the server to apply the validation algorithm every time the pool returns a connection which adds overhead to the latency of getConnection Ifthe database connectivity is reliable you can omit validation Type of connection validation to perform Must be one of auto commit attempt to perform an auto commit on the connection metadata attempt to get metadata from the connection table performing a query on a specified table Must also set Table Name You may have to use this method if the JDBC driver
122. proved functional properties Functional properties such as user time out commit options security and transaction options are mostly related to the functionality and configuration of the application Generally they do not compromise functionality for performance In some cases you might be forced to make a trade off decision between functionality and performance This section offers suggestions in such cases Monitoring EJB Components When the EJB container has monitoring enabled you can examine statistics for individual beans based on the bean pool and cache settings For example the monitoring command below gives the Bean Cache statistics for a stateful session bean Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 EJB Performance Tuning asadmin get user admin host e4800 241 a port 4848 m specjcmp application SPECjAppServer ejb module supplier jar stateful session bean BuyerSes bean cache The following is a sample of the monitoring output resize quantity 1 cache misses 0 idle timeout in seconds 0 num passivations 0 cache hits 59 num passivation errors 0 total beans in cache 59 num expired sessions removed 0 max beans in cache 4096 num passivation success 0 The monitoring command below gives the bean pool statistics for an entity bean asadmin get user admin host e4800 241 a port 4848 m specjcmp application SPECjAppServer ejb module supplier
123. ptimize performance tune the HADB according to the load of the Enterprise Server The data volume transaction frequency and size of each transaction can affect the performance of the HADB and consequently the performance of Enterprise Server This section discusses following topics Disk Use on page 107 Memory Allocation on page 109 Performance on page 110 Operating System Configuration on page 116 Disk Use This section discusses how to calculate HADB data device size and explains the use of separate disks for multiple data devices Calculating HADB Data Device Size When the HADB database is created specify the number and size of each data device These devices must have room for all the user data to be stored In addition allocate extra space to account for internal overhead as discussed in the following section 107 Tuning HADB 108 Ifthe database runs out of device space the HADB returns error codes 4593 or 4592 to the Enterprise Server Note See Sun Java System Application Server Error Message Reference for more information on these error messages HADB also writes these error messages to history files In this case HADB blocks any client requests to insert or update data However it will accept delete operations HADB stores session states as binary data It serializes the session state and stores it as a BLOB binary large object It splits each BLOB into chunks of approximately 7KB each and st
124. r Solaris and Linux installations root user opt SUNWappserver Windows all installations SystemDrive Sun AppServer domain root dir Represents the directory containing all domains All installations as install domains domain dir Represents the directory for a domain In configuration files you might see domain dir represented as follows com sun aas instanceRoot domain root dir domain dir instance dir Represents the directory for a server instance domain dir instance dir samples dir Represents the directory containing sample as install samptes applications docs dir Represents the directory containing as install docs documentation 14 Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Preface Typographic Conventions The following table describes the typographic changes that are used in this book TABLEP 3 Typographic Conventions Typeface Meaning Example AaBbCc123 The names of commands files and Edit your Login file directories and onscreen computer P Use ls a to list all files output machine name you have mail AaBbCc123 What you type contrasted with onscreen machine names su computer output P P Password AaBbCc123 A placeholder to be replaced with a real The command to remove a file is rm filename name or value AaBbCc123 Book titles new terms and terms to be Read Chapter 6 in the User s Guide emphas
125. r example the output displayed by this command might look something like this Node No Avail Free Waits 0 50000 50000 na 1 50000 50000 na Avail Number of locks available Free Number of locks in use Waits Number of transactions that have waited for a lock na not applicable if all locks are available To change the number of locks use the following command hadbm set NumberOfLocks The hadbm restarts all the nodes one by one for the change to take effect For more information on using this command see Configuring HADB in Sun GlassFish Enterprise Server 2 1 High Availability Administration Guide Timeouts This section describes some of the timeout values that affect performance JDBC connection pool timeouts These values govern how much time the server waits for a connection from the pool before it times out In most cases the default values work well For detailed tuning information see Tuning JDBC Connection Pools on page 77 Load Balancer timeouts Some values that may affect performance are m response timeout in seconds The time for which the load balancer plug in will wait for a response before it declares an instance dead and fails over to the next instance in the cluster Make this value large enough to accommodate the maximum latency for a request from the server instance under the worst high load conditions health checker interval in seconds Determines how frequently the lo
126. r takes n seconds and under peak load takes m seconds then set the timeout in seconds property to m n as follows health checker url http hostname domain port interval in seconds n timeout in seconds m n gt Chapter6 Tuning for High Availability 121 122 Index A Acceptor Threads 69 access log 64 AddrLookups 62 application architecture 19 scalability 24 tuning 27 arrays 27 authentication 21 authorization 21 automatic recovery 60 Average Queuing Delay 64 B Bcommit option 57 bandwidth 94 benchmarking tuning Solaris for 104 best practices 27 Buffer Length HTTP Service 66 C Ccommitoption 57 cacheDatabaseMetaData 120 CacheEntries 61 caching EJB components 53 54 message driven beans 48 caching Continued servlet results 31 capacity planning 24 checkpointing 43 119 class variables shared 30 Client ORB Properties 73 74 Close All Connections On Any Failure JDBC Connection Pool 80 CMS collector 85 coding guidelines 27 29 commitoptions 57 58 Common Data Representation CDR 75 configuration tips 31 connection hash table 96 Connection Validation Required JDBC Connection Pool 80 Connection Validation Settings JDBC Connection Pool 79 80 connector connection pools 80 constants 28 container managed relationship 44 container managed transactions 38 context factory 73 D data devicesize 107 database buffer 110 DataBufferP
127. rectory Access Protocol LDAP 21 Linux 100 load balancer 120 locks HADB 113 log level 51 LogBufferSize 108 111 112 loggersettings 50 51 LookupsInProgress 62 M Max Age HTTP filecache 68 max cache size 56 Max Files Count HTTP filecache 68 Max Message Fragment Size ORB 72 max pool size 54 MaxNewSize 88 memory 94 109 message driven beans 47 monitoring EJB container 32 file cache 63 HTTP service 60 JDBC connection pools 77 ORB 70 71 125 Index monitoring Continued transaction service 58 N NameLookups 62 Network Address 69 network configuration 105 network interface 102 network interrupts disabling 105 NewRatio 88 NewSize 88 Node Supervisor Process NSUP 109 null assigning 28 NumberOfLocks 113 115 o open files 97 101 operating system tuning 93 106 operational requirements 19 23 ORB 70 76 Client properties 73 74 IIOP Client Authentication Required 72 Max Message Fragment Size 72 monitoring 70 71 Thread PoolID 72 thread pools 71 Total Connections 72 tuning 71 P pagesizes 105 106 pass by reference 37 38 pass by value 37 pauses 86 persistence frequency 117 persistence scope 118 poolsize message driven bean 47 pre compiled JSP files 50 pre fetching EJB components 44 processors 93 programming guidelines 27 29 promptness 86 R read only beans 43 44 refresh period 44 56 reap interval 52 recover on restart 60 re
128. ry resources Enterprise Profile targeted at production deployments uses the default JVM startup mode By default Application Server uses the client Hotspot VM However if a server VM is needed it can be specified by creating a lt jvm option gt named server You can override the default by changing the JVM settings in the Admin Console under Configurations gt config name gt JVM Settings JVM Options For more information on server class machine detection in J2SE 5 0 see Server Class Machine Detection For more information on JVMs see Java TM Virtual Machines 83 Managing Memory and Garbage Collection Managing Memory and Garbage Collection 84 The efficiency of any application depends on how well memory and garbage collection are managed The following sections provide information on optimizing memory and allocation functions Goals on page 32 Tracing Garbage Collection on page 86 m Other Garbage Collector Settings on page 86 Tuning the Java Heap on page 87 Rebasing DLLs on Windows on page 89 Further Information on page 91 Tuning the Garbage Collector Garbage collection GC reclaims the heap space previously allocated to objects no longer needed The process of locating and removing the dead objects can stall any application and consume as much as 25 percent throughput Almost all Java Runtime Environments come with a generational object memory system and sophisticated
129. s all users You could also specify a user ID instead Then edit etc pam d login and add the line session required lib security pam limits so On Red Hat you also need to edit etc pam d sshd and add the following line session required lib security pam limits so On many systems this procedure will be sufficient Log in as a regular user and try it before doing the remaining steps The remaining steps might not be required depending on how pluggable authentication modules PAM and secure shell SSH are configured Virtual Memory To change virtual memory settings add the following to etc rc local echo 100 1200 128 512 15 5000 500 1884 2 gt proc sys vm bdflush For more information view the man pages for bdflush For HADB settings refer to Chapter 6 Tuning for High Availability Chapter5 Tuning the Operating System and Platform 101 Tuning for Linux platforms 102 Network Interface To ensure that the network interface is operating in full duplex mode add the following entry into etc rc local mii tool F 100baseTx FD eth0 where eth0 is the name ofthe network interface card NIC Disk I O Settings To tune disk I O performance for non SCSI disks Test the disk speed Use this command sbin hdparm t dev hdX Enable direct memory access DMA Use this command sbin hdparm d1 dev hdX Checkthe speed again using the hdparm command Given that DMA is not enabled by default the transfer rat
130. s information on tuning applications for maximum performance A complete guide to writing high performance Java and Java EE applications is beyond the scope ofthis document This chapter discusses the following topics Java Programming Guidelines on page 27 Java Server Page and Servlet Tuning on page 29 EJB Performance Tuning on page 32 Java Programming Guidelines This section covers issues related to Java coding and performance The guidelines outlined are not specific to Enterprise Server but are general rules that are useful in many situations For a complete discussion of Java coding best practices see the Java Blueprints Avoid Serialization and Deserialization Serialization and deserialization of objects is a CPU intensive procedure and is likely to slow down your application Use the transient keyword to reduce the amount of data serialized Additionally customized read0bject and writeObject methods may be beneficial in some cases Use StringBuffer to Concatenate Strings To improve performance instead of using string concatenation use StringBuffer append String objects are immutable they never change after creation For example consider the following code 27 Java Programming Guidelines 28 String str testing str str abc The compiler translates this code as String str testing StringBuffer tmp new StringBuffer str tmp append abc str tmp toString
131. se pass by reference semantics when possible Using the remote and local interfaces appropriately means that clients can access EJB components efficiently That is local clients use the local interface with pass by reference semantics while remote clients use the remote interface with pass by value semantics However in some instances it might not be possible to use the local interface for example when The application predates the EJB 2 0 specification and was written without any local interfaces There are bean to bean calls and the client beans are written without making any co location assumptions about the called beans For these cases the Enterprise Server provides a pass by reference option that clients can use to pass arguments by reference to the remote interface of a co located EJB component You can specify the pass by reference option for an entire application or a single EJB component When specified at the application level all beans in the application use pass by reference semantics when passing arguments to their remote interfaces When specified at the bean level all calls to the remote interface ofthe bean use pass by reference Chapter2 Tuning Your Application 37 EJB Performance Tuning 38 semantics See Value Added Features in Sun GlassFish Enterprise Server 2 1 Developers Guide for more details about the pass by reference flag To specify that an EJB component will use pass by reference seman
132. server farm The Application Server supports virtual server capability for web applications For example a web application hosting service provider can host different URL domains on a single Application Server process for efficient administration For detailed information on administration see Sun GlassFish Enterprise Server 2 1 Administration Guide General Tuning Concepts Some key concepts that affect performance tuning are User load Application scalability Margins of safety The following table describes these concepts and how they are measured in practice The left most column describes the general concept the second column gives the practical ramifications of the concept the third column describes the measurements and the right most column describes the value sources Chapter 1 Overview of Enterprise Server Performance Tuning 23 General Tuning Concepts TABLE 1 2 Factors That Affect Performance Concept In practice Measurement Value sources User Load Concurrent Transactions Per Minute TPM Max number of concurrent users expected response time sessions at time between clicks Web Interactions Per Second peak load WIPS Example 100 users 2 sec 10 sec 20 Application Transaction TPM or WIPS Measured from workload benchmark Perform at each tier Scalability rate measured on one CPU Vertical Increase in Percentage gain per additional Based on curv
133. sole provides the following performance related keep alive statistics Connections Terminated Due to ClientConnection Timed Out Max Connection Allowed in Keep alive Number of Hits Connections in Keep alive Mode Connections not Handed to Keep alive Thread Due to too Many Persistent Connections The Time in Seconds Before Idle Connections are Closed Connections Closed Due to Max Keep alive Being Exceeded Chapter3 Tuning the Enterprise Server 63 HTTP Service Settings 64 Connection Queue Total Connections Queued Total connections queued is the total number of times a connection has been queued This includes newly accepted connections and connections from the keep alive system Average Queuing Delay Average queueing delay is the average amount of time a connection spends in the connection queue This represents the delay between when a request connection is accepted by the server and a request processing thread also known as a session begins servicing the request Tuning the HTTP Service The settings for the HTTP service are divided into the following categories in the Admin Console Access Log on page 64 Request Processing on page 64 Keep Alive on page 66 HTTP Protocol on page 67 HTTP File Cache on page 67 Access Log When performing benchmarking ensure that access logging is disabled If you need to disable access logging in HTTP Service click Add Property and add the
134. ss logged 105 HTTP file cache 67 68 Hash Init Size 68 Max Age 68 Max Files Count 68 Small Medium File Size 68 HTTP listener settings 69 HTTP protocol 67 HTTP Service 60 Buffer Length 66 Initial Thread Count 65 keep alive settings 66 monitoring 60 Request Timeout 65 Thread Count 65 124 Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Index HTTP Service Continued tuning 64 HTTP sessions 30 idle timeout EJB cache 56 EJB pool 55 IIOP Client Authentication Required 72 IIOP messages 74 75 Initial Thread Count HTTP Service 65 InternalLogbufferSize 112 113 ipip squeue bind 104 ipip squeue fanout 104 IPstack 99 ipge ipge_bcopy_thresh 104 ipge ipge_srv_fifo_depth 104 ipge ipge_taskq_disable 104 ipge ipge_tx_ring size 104 ipge ipge_tx_syncq 104 J Java coding guidelines 27 29 Java Heap 87 89 Java serialization 75 76 Java Virtual Machine JVM 83 JAX RPC 29 JDBC Connection Pool 77 Close All Connections On Any Failure 80 Connection Validation Required 80 Connection Validation Settings 79 80 HADB 119 Table Name 80 Validation Method 80 JDBC resources 39 tips 46 47 JMS connections 48 local vs remote service 58 tips 47 48 JSP files 29 pre compiling 50 reloading 52 tuning 29 31 jvmstat utility 85 K keep alive max connections 66 settings 66 statistics 63 timeout 67 L last agent optimization LAO 39 Lighweight Di
135. stances Using one or more external load balancers can efficiently spread user access across all the application server instances A horizontal scaling approach may improve availability lower hardware costs and is suitable for some types of applications However this approach requires administration of more application server instances and hardware nodes Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 General Tuning Concepts Administration A single Application Server installation on a server can encompass multiple instances A group of one or more instances that are administered by a single Administration Server is called a domain Grouping server instances into domains permits different people to independently administer the groups You can use a single instance domain to create a sandbox for a particular developer and environment In this scenario each developer administers his or her own application server without interfering with other application server domains A small development group may choose to create multiple instances in a shared administrative domain for collaborative development Ina deployment environment an administrator can create domains based on application and business function For example internal Human Resources applications may be hosted on one or more servers in one Administrative domain while external customer applications are hosted on several administrative domains in a
136. t files Enabling the HTTP file cache will improve performance of applications that contain static files Set the file cache attributes in the Admin Console under Configurations gt config name gt HTTP Service HTTP File Cache Chapter3 Tuning the Enterprise Server 67 HTTP Service Settings 68 Max Files Count Max Files Count determines how many files are in the cache Ifthe value is too big the server caches little needed files which wastes memory If the value is too small the benefit of caching is lost Try different values of this attribute to find the optimal solution for specific applications generally the effects will not be great Hash Init Size Hash Init Size affects memory use and search time but rarely will have a measurable effect on performance Max Age This parameter controls how long cached information is used after a file has been cached An entry older than the maximum age is replaced by a new entry for the same file If your web site s content changes infrequently increase this value for improved performance Set the maximum age by entering or changing the value in the Maximum Age field of the File Cache Configuration page in the web based Admin Console for the HTTP server node and selecting the File Caching Tab Set the maximum age based on whether the content is updated existing files are modified on a regular schedule or not For example if content is updated four times a day at regular i
137. t garbage collector In general for long running server applications use the J2SE throughput collector on machines with multiple processors XX AggressiveHeap and as large a heap as you can fit in the free memory of your machine Heap Tuning Parameters You can control the heap size with the following JVM parameters Xmsvalue m Xmxvalue m XX MinHeapFreeRatio minimum XX MaxHeapFreeRatio maximum XX NewRatio ratio XX NewSize size XX MaxNewSize size XX AggressiveHeap The Xms and Xmx parameters define the minimum and maximum heap sizes respectively Since GC occurs when the generations fill up throughput is inversely proportional to the amount of the memory available By default the JVM grows or shrinks the heap at each GC to try to keep the proportion of free space to the living objects at each collection within a specific range This range is set as a percentage by the parameters XX MinHeapFreeRatio minimum and XX MaxHeapF reeRat io maximum and the total size bounded by Xms and Xmx Set the values of Xms and Xmx equal to each other for a fixed heap size When the heap grows or shrinks the JVM must recalculate the old and new generation sizes to maintain a predefined NewRatio The NewSize and MaxNewSize parameters control the new generation s minimum and maximum size Regulate the new generation size by setting these parameters equal The bigger the younger generation the less often minor collections occur The
138. t the log level to FINE FINER or FINEST For best performance under normal conditions set the log level to WARNING Under benchmarking conditions it is often appropriate to set the log level to SEVERE Web Container Settings Set Web container properties with the Admin Console at Configurations gt config name gt Web Container Session Properties Session Timeout on page 51 Manager Properties Reap Interval on page 52 Disable Dynamic JSP Reloading on page 52 Session Properties Session Timeout Session timeout determines how long the server maintains a session if a user does not explicitly invalidate the session The default value is 30 minutes Tune this value according to your application requirements Setting a very large value for session timeout can degrade performance by causing the server to maintain too many sessions in the session store However setting a very small value can cause the server to reclaim sessions too soon Chapter 3 Tuning the Enterprise Server 51 Web Container Settings 52 Manager Properties Reap Interval Modifying the reap interval can improve performance but setting it without considering the nature of your sessions and business logic can cause data inconsistency especially for time based persistence frequency For example if you set the reap interval to 60 seconds the value of session data will be recorded every 60 seconds But ifa client accesses a servlet to update a
139. te clients use the remote interface to access the bean Calls to the remote interface require marshalling arguments transportation ofthe marshalled data over the network un marshaling the arguments and dispatch at the receiving end Thus using the remote interface entails significant overhead If an EJB component has a local interface then local clients in the same application server instance can use it instead ofthe remote interface Using the local interface is more efficient since it does not require argument marshalling transportation and un marshalling If a bean is to be used only by local clients then it makes sense to provide only the local interface If on the other hand the bean is to be location independent then you should provide both the remote and local interfaces so that remote clients use the remote interface and local clients can use the local interface for efficiency Using Pass By Reference Semantics By default the Enterprise Server uses pass by value semantics for calling the remote interface of a bean even if it is co located This can be expensive since clients using pass by value semantics must copy arguments before passing them to the EJB component However local clients can use pass by reference semantics and thus the local and remote interfaces can share the passed objects But this means that the argument objects must be implemented properly so that they are shareable In general it is more efficient to u
140. than 30 seconds The maximum value for this parameter is 300 seconds 5 minutes The proper value for this parameter depends upon how much time is expected to elapse between requests from a given client For example if clients are expected to make requests frequently then set the parameter to a high value likewise if clients are expected to make requests rarely then set it to a low value HTTP Protocol The only HTTP Protocol attribute that significantly affects performance is DNS Lookup Enabled DNS Lookup Enabled This setting specifies whether the server performs DNS domain name service lookups on clients that access the server When DNS lookup is not enabled when a client connects the server knows the client s IP address but not its host name for example it knows the client as 198 95 251 30 rather than ww xyz com When DS lookup is enabled the server will resolve the client s IP address into a host name for operations like access control common gateway interface CGI programs error reporting and access logging Ifthe server responds to many requests per day reduce the load on the DNS or NIS Network Information System server by disabling DNS lookup Enabling DNS lookup will increase the latency and load on the system do so with caution HTTPFile Cache The Enterprise Server uses a file cache to serve static information faster The file cache contains information about static files such as HTML CSS image or tex
141. that are used frequently for example an item in the inventory that gets referenced very often are cached more in numbers Stateful Session Beans When a stateful bean represents a user a reasonable max cache size of beans is the expected number of concurrent users on the application server process If this value is too low in relation Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 EJB Performance Tuning to the steady load of users beans would be frequently passivated and activated causing a negative impact on the response times due to CPU intensive serialization and deserialization as wellas disk I O Another important variable for tuning is cache idle timeout in seconds where at periodic intervals of cache idle timeout in seconds all the beans in the cache that have not been accessed for more than cache idle timeout in seconds time are passivated Similar to an HTTP session time out the bean is removed after it has not been accessed for removal timeout in seconds Passivated beans are stored on disk in serialized form A large number of passivated beans could not only mean many files on the disk system but also slower response time as the session state has to be de serialized before the invocation Checkpoint only when needed In high availability mode when using stateful session beans consider checkpointing only those methods that alter the state of the bean significantly This reduces the
142. the bean has an identity for example a primary key or session ID associated with it Beans moving out of the cache have to be passivated or destroyed according to the EJB lifecycle Once passivated a bean has to be activated to come back into the cache Entity beans are generally stored in databases and use some form of query language semantics to load and store data Session beans have to be serialized when storing them upon passivation onto the disk or a database and similarly have to be deserialized upon activation Any incoming request using these ready beans from the cache avoids the overhead of creation setting identity and potentially activation So theoretically it is good to cache as many beans as possible However there are drawbacks to caching Memory consumed by all the beans affects the heap available in the Virtual Machine Increasing objects and memory taken by cache means longer and possibly more frequent garbage collection The application server might run out of memory unless the heap is carefully tuned for peak loads Keeping in mind how your application uses stateful session beans and entity beans and the amount of traffic your server handles tune the EJB cache size and time out settings to minimize the number of activations and passivations EJB Cache Settings An individual EJB component can specify cache settings that override those of the EJB container in the lt bean cache element of the EJB
143. tics use the following tag in the sun ejb jar xml deployment descriptor lt pass by reference gt true lt pass by reference gt This avoids copying arguments when the EJB components methods are invoked and avoids copying results when methods return However problems will arise if the data is modified by another source during the invocation Improving Performance of EJB Transactions This section provides some tips to improve performance when using transactions Use Container Managed Transactions Container managed transactions are preferred for consistency and provide better performance Don t Encompass User Input Time To avoid resources being held unnecessarily for long periods a transaction should not encompass user input or user think time Identify Non Transactional Methods Declare non transactional methods of session EJB components with NotSupported or Never transaction attributes These attributes can be found in the ejb jar xml deployment descriptor file Transactions should span the minimum time possible since they lock database rows Use TX REQUIRED for Long Transaction Chains For very large transaction chains use the transaction attribute TX REQUIRED To ensure EJB methods in a call chain use the same transaction Use Lowest Cost Database Locking Use the lowest cost locking available from the database that is consistent with any transaction Commit the data after the transaction completes rather than after ea
144. tion of hardware encryption cards for even higher performance Security considerations particularly when using the integrated software encryption will impact hardware sizing and capacity planning Consider the following when assessing the encryption needs for a deployment Chapter 1 Overview of Enterprise Server Performance Tuning 21 Understanding Operational Requirements 22 Whatisthe nature ofthe applications with respect to security Do they encrypt all or only a part ofthe application inputs and output What percentage of the information needs to be securely transmitted Are the applications going to be deployed on an application server that is directly connected to the Internet Will a web server exist in a demilitarized zone DMZ separate from the application server tier and backend enterprise systems A DMZ style deployment is recommended for high security It is also useful when the application has a significant amount of static text and image content and some business logic that executes on the Application Server behind the most secure firewall Application Server provides secure reverse proxy plugins to enable integration with popular web servers The Application Server can also be deployed and used as a web server in DMZ Is encryption required between the web servers in the DMZ and application servers in the next tier The reverse proxy plugins supplied with Application Server support SSL encryption between the web
145. tion pool and when you edit a connector connection pool at Resources gt Connectors gt Connector Connection Pools Also set transaction support using asadmin For example the following asadmin command could be used to create a connector connection pool TESTPOOL with the transaction support as LOCAL Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Close All Connections On Any Failure asadmin create connector connection pool raname jdbcra connectiondefinition javax sql DataSource transactionsupport LocalTransaction TESTPOOL Chapter3 Tuning the Enterprise Server 81 82 gt CHAPTER 4 Tuning the Java Runtime System This chapter discusses the following topics Java Virtual Machine Settings on page 83 Managing Memory and Garbage Collection on page 84 Further Information on page 91 Java Virtual Machine Settings J2SE 5 0 provides two implementations of the HotSpot Java virtual machine JV M The client VM is tuned for reducing start up time and memory footprint Invoke it by using the client JVM command line option The server VM is designed for maximum program execution speed Invoke it by using the server JVM command line option By default the Application Server uses the JVM setting appropriate to the purpose Developer Profile targeted at application developers uses the client JVM flag to optimize startup performance and conserve memo
146. tries Products bearing SPARC trademarks are based upon an architecture developed by Sun Microsystems Inc The OPEN LOOK and Sun Graphical User Interface was developed by Sun Microsystems Inc for its users and licensees Sun acknowledges the pioneering efforts of Xerox in researching and developing the concept of visual or graphical user interfaces for the computer industry Sun holds a non exclusive license from Xerox to the Xerox Graphical User Interface which license also covers Sun s licensees who implement OPEN LOOK GUIs and otherwise comply with Sun s written license agreements Products covered by and information contained in this publication are controlled by U S Export Controllaws and may be subject to the export or import laws in other countries Nuclear missile chemical or biological weapons or nuclear maritime end uses or end users whether direct or indirect are strictly prohibited Export or reexport to countries subject to U S embargo or to entities identified on U S export exclusion lists including but not limited to the denied persons and specially designated nationals lists is strictly prohibited DOCUMENTATION IS PROVIDED AS IS AND ALL EXPRESS OR IMPLIED CONDITIONS REPRESENTATIONS AND WARRANTIES INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY FITNESS FOR A PARTICULAR PURPOSE OR NON INFRINGEMENT ARE DISCLAIMED EXCEPT TO THE EXTENT THAT SUCH DISCLAIMERS ARE HELD TO BE LEGALLY INVALID Copyright 2009 S
147. u can prevent pre fetching for the findByCustomerId method by including this information in the sun ejb jar xml descriptor lt ejb gt lt ejb name gt OrderBean lt ejb name gt lt cmp gt lt prefetch disabled gt lt query method gt lt method name gt f indByCustomerId lt method name gt lt query method gt lt prefetch disabled gt lt cmp gt lt ejb gt JDBC and Database Access Here are some tips to improve the performance of database access Use JDBC Directly When dealing with large amounts of data such as searching a large database use JDBC directly rather than using Entity EJB components Encapsulate Business Logic in Entity EJB Components Combine business logic with the Entity EJB component that holds the data needed for that logic to process Close Connections To ensure that connections are returned to the pool always close the connections after use Minimize the Database Transaction Isolation Level Use the default isolation level provided by the JDBC driver rather than calling setTransactionIsolationLevel unless you are certain that your application behaves correctly and performs better at a different isolation level Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 EJB Performance Tuning Reduce the database transaction isolation level when appropriate Reduced isolation levels reduce work in the database tier and could lead to better application performance
148. ue Setting this attribute to true disables transaction logging which can improve performance Setting it to false the default makes the transaction service write transactional activity to transaction logs so that transactions can be recovered If Recover on Restart is checked this property is ignored Set this property to true only if performance is more important than transaction recovery Chapter3 Tuning the Enterprise Server 59 HTTP Service Settings Recover On Restart Automatic Recovery To set the Recover on Restart attribute with the Admin Console go to Configurations gt config name Transaction Service Click the Recover check box to set it to true checked the default or false un checked You can also set automatic recovery with asadmin for example asadmin set serverl transaction service automatic recovery false When Recover on Restart is true the server will always perform transaction logging regardless ofthe Disable Distributed Transaction Logging attribute If Recover on Restart is false then IfDisable Distributed Transaction Logging is false the default then the server will write transaction logs IfDisable Distributed Transaction Logging is true then the server will not write transaction logs Not writing transaction logs will give approximately twenty percent improvement in performance but at the cost of not being able to recover from any interrupted transactions The performance be
149. uire multiple database queries one for the Order bean and one for each of the OrderLine beans in the relationship In general if a bean has n relationships using all the data ofthe bean would require n 1 database accesses Use CMR pre fetching to retrieve all the data for the bean and all its related beans in one database access Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 EJB Performance Tuning For example you have this relationship defined in the ejb jar xmt file relationships ejb relation lt description gt Order OrderLine lt description gt lt ejb relation name gt Order OrderLine lt ejb relation name gt lt ejb relationship role gt lt ejb relationship role name gt Order has N OrderLines ejb relationship role name lt multiplicity gt One lt multiplicity gt lt relationship role source gt lt ejb name gt OrderEJB lt ejb name gt lt relationship role source gt lt cmr field gt lt cmr field name gt orderLines lt cmr field name gt lt cmr field type gt java util Collection lt cmr field type gt lt cmr field gt lt ejb relationship role gt lt ejb relation gt lt relationships gt When a particular Order is loaded you can load its related OrderLines by adding this to the sun cmp mapping xml file for the application lt entity mapping gt lt ejb name gt Order lt ejb name gt lt table name gt lt table name gt lt cmp field mapping gt lt c
150. umber of address loops IP address to DNS name that have been done since the server was started This setting is not tunable LookupsinProgress The current number oflookups in progress Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 HTTP Service Settings File Cache Information file cache The file cache caches static content so that the server handles requests for static content quickly The file cache section provides statistics on how your file cache is being used For information on tuning the file cache see HTTP File Cache on page 67 Number of Hits on Cached File Content Number of Cache Entries Number of Hits on Cached File Info Heap Space Used for Cache Number of Misses on Cached File Content Cache Lookup Misses Number of Misses on Cached File Content Max Age of a Cache Entry The maximum age displays the maximum age of a valid cache entry Max Number of Cache Entries Max Number of Open Entries Is File Cached Enabled If the cache is disabled the other statistics are not displayed The cache is enabled by default Maximum Memory Map to be Used for Cache Memory Map Used for cache Cache Lookup Hits Open Cache Entries The number of current cache entries and the maximum number of cache entries are both displayed A single cache entry represents a single URI This is a tunable setting Maximum Heap Space to be Used for Cache Keep Alive keep alive The Admin Con
151. umber of file descriptors ensures that the server can open sockets under high load and not abort requests coming in from clients Start by checking system limits for file descriptors with this command cat proc sys fs file max 8192 The current limit shown is 8192 To increase it to 65535 use the following command as root echo 65535 proc sys fs file max To make this value to survive a system reboot add it to etc sysctl conf and specify the maximum number of open files permitted fs file max 65535 Note The parameter is not proc sys fs file max as one might expect To list the available parameters that can be modified using sysctl sysctl a To load new values from the sysctl conf file sysctl p etc sysctl conf To check and modify limits per shell use the following command limit The output will look something like this Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Tuning for Linux platforms cputime unlimited filesize unlimited datasize unlimited stacksize 8192 kbytes coredumpsize 0 kbytes memoryuse unlimited descriptors 1024 memorylocked unlimited maxproc 8146 openfiles 1024 The openfiles and descriptors show a limit of 1024 To increase the limit to 65535 for all users edit etc security limits conf as root and modify or add the nofile setting number of file entries soft nofile 65535 hard nofile 65535 The character is a wildcard that identifie
152. un Microsystems Inc 4150 Network Circle Santa Clara CA 95054 U S A Tous droits r serv s Sun Microsystems Inc d tient les droits de propri t intellectuelle relatifs la technologie incorpor e dans le produit qui est d crit dans ce document En particulier et ce sans limitation ces droits de propri t intellectuelle peuvent inclure un ou plusieurs brevets am ricains ou des applications de brevet en attente aux Etats Unis et dans d autres pays Cette distribution peut comprendre des composants d velopp s par des tierces personnes Certaines composants de ce produit peuvent tre d riv es du logiciel Berkeley BSD licenci s par l Universit de Californie UNIX est une marque d pos e aux Etats Unis et dans d autres pays elle est licenci e exclusivement par X Open Company Ltd Sun Sun Microsystems le logo Sun le logo Solaris le logo Java Coffee Cup docs sun com OpenSolaris Java et Solaris sont des marques de fabrique ou des marques d pos es de Sun Microsystems Inc ou ses filiales aux Etats Unis et dans d autres pays Toutes les marques SPARC sont utilis es sous licence et sont des marques de fabrique ou des marques d pos es de SPARC International Inc aux Etats Unis et dans d autres pays Les produits portant les marques SPARC sont bas s sur une architecture d velopp e par Sun Microsystems Inc L interface d utilisation graphique OPEN LOOK et Sun a t d velopp e par Sun Microsystems Inc pour ses
153. uning the Operating System and Platform Server Scaling a2 iens eden e d deed dic eddy nte de cuisse deu Ree nent sont nO E T M 93 M MO dioe siipom tine detegit o o an Ye Bodom edd I o udi 94 Disk Space D 94 Es sup T 94 Solaris 10 Platform Specific Tuning Information ssie tenete 95 Tuning forthe Solaris OS aede dieta ertet died etit e amarte mend on 95 Tuning Parameters pesine osei o ique ro nivei iiri n dU Heer YR TAA ERU EDS 95 File Descriptor Setting Lac reiecit n ect tener ero aan re RR ve ste v de 97 Linux Connora Sd dao uieaeee tad tee corii e a de e UN t rH Hc e Erbe Tuning for Solaris on x86 Pie MSS CHa GOES Mr E IP St ck Settings E M Tuning for Linux platforms Dp nanamin 100 File Descriptors Virtual Memory Network Interface Contents 6 DISKL O Settings sis ccssssssssssssesssonsessacivsstosensestaseassdeossonspesasess os soseaescastasssassbenteenesdstusebaasasusassoasssdees 102 TGP IP Settlnpgsso 2 aset d eet eek Re e ave eiTe SA en tte 102 Tuning UltraSPARC TI Based Systems nue dec ean etia dee eria 103 Tuning Operating System and TCP Settings sense 103 Disk Con MS Ue at Om zoom aate ment istae epa e n dud ea Rd Raus Network Configuration Start OPTIONS ins ri eee in ne e des iHa in Ue code REP ae He a QNO Ms Tuning for High Availab
154. us requests Adjust the thread count value based on your load and the length of time for an average request In general increase this number if you have idle CPU time and requests that are pending decrease it ifthe CPU becomes overloaded If you have many HTTP 1 0 clients or HTTP 1 1 clients that disconnect frequently adjust the timeout value to reduce the time a connection is kept open Suitable Request Thread Count values range from 100 to 500 depending on the load If your system has extra CPU cycles keep incrementally increasing thread count and monitor performance after each incremental increase When performance saturates stops improving then stop increasing thread count Initial Thread Count The Initial Thread Count property specifies the minimum number of threads the server initiates upon start up The default value is 2 Initial Thread Count represents a hard limit for the maximum number of active threads that can run simultaneously which can become a bottleneck for performance Request Timeout The Request Timeout property specifies the number of seconds the server waits between accepting a connection to a client and receiving information from it The default setting is 30 seconds Under most circumstances changing this setting is unnecessary By setting it to less than the default 30 seconds it is possible to free up threads sooner However disconnecting users with slower connections also helps Chapter 3 Tuning the
155. utilisateurs et licenci s Sun reconnait les efforts de pionniers de Xerox pour la recherche et le d veloppement du concept des interfaces d utilisation visuelle ou graphique pour l industrie de l informatique Sun d tient une licence non exclusive de Xerox sur l interface d utilisation graphique Xerox cette licence couvrant galement les licenci s de Sun qui mettent en place l interface d utilisation graphique OPEN LOOK et qui en outre se conforment aux licences crites de Sun Les produits qui font l objet de cette publication et les informations qu il contient sont r gis par la legislation am ricaine en mati re de contr le des exportations et peuvent tre soumis au droit d autres pays dans le domaine des exportations et importations Les utilisations finales ou utilisateurs finaux pour des armes nucl aires des missiles des armes chimiques ou biologiques ou pour le nucl aire maritime directement ou indirectement sont strictement interdites Les exportations ou r exportations vers des pays sous embargo des Etats Unis ou vers des entit s figurant sur les listes d exclusion d exportation am ricaines y compris mais de mani re non exclusive la liste de personnes qui font objet d un ordre de ne pas participer d une facon directe ou indirecte aux exportations des produits ou des services qui sont r gis par la legislation am ricaine en mati re de contr le des exportations et la liste de ressortissants sp cifiquement design s sont ri
156. v hiwat ndd dev tcp 8129 32768 Tuning UltraSPARC T1 Based Systems Use a combination of tunable parameters and other parameters to tune UltraSPARC T1 based systems These values are an example of how you might tune your system to achieve the desired result Tuning Operating System and TCP Settings The following table shows the operating system tuning for Solaris 10 used when benchmarking for performance and scalability on UtraSPARC T1 based systems 64 bit systems Chapter5 Tuning the Operating System and Platform 103 Tuning UltraSPARC T1 Based Systems TABLE5 2 Tuning 64 bit Systems for Performance Benchmarking Parameter Scope Default Value Tuned Value Comments rlim_fd_max etc system 65536 260000 Process open file descriptors limit should account for the expected load for the associated sockets files pipes ifany hires tick etc system 1 sq max size etc system 2 0 Controls streams driver queue size setting to 0 makes it infinite so the performance runs won t be hit by lack of buffer space Set on clients too Note that setting sq max sizeto0 might not be optimal for production systems with high network traffic ip ip squeue bind 0 ip ip squeue fanout 1 ipge ipge taskq disable etc system 0 ipge ipge tx ring size etc system 2048 ipge ipge srv fifo depth etc system 2048 ipge ipge bcopy thresh etc system 384 ipge ipge dvma thresh etc system 384 ipg
157. y using routines in the appropriate operating system library for concurrent access to heap space The library to use depends on the version ofthe Solaris Operating System SolarisOS that you are using To ensure that you use the correct library set the LD PRELOAD environment variable to specify the correct library file For mor information see the following table Solaris OS Version Library Setting of LD PRELOAD Environment Variable 10 libumem 3LIB usr lib libumem so 9 libmtmalloc 3LIB usr lib libmtmalloc so TosettheLD PRELOAD environment variable edit the entry for this environment variable in the startserv script The startserv script is located is located in the bin startserv directory of your domain The exact syntax to define an environment variable depends on the shell that you are using Disable Security Manager The security manager is expensive because calls to required resources must call the doPrivileged method and must also check the resource with the server policy file If you are sure that no malicious code will be run on the server and you do not use authentication within your application then you can disable the security manager To disable use of the server policy file use the Admin Console Under Configurations gt config name JVM Settings JVM Options delete the option that contains the following text Djava security manager Chapter2 Tuning Your Application 31 EJB Performance Tuning
158. ze for session modified session or attribute size for modified attribute Then the number of records written to HADB is xy 7000 2x Record operations such as insert delete update and read will use one lock per record Note Locks are held for both primary records and hot standby records Hence for insert update and delete operations a transaction will need twice as many locks as the number of records Read operations need locks only on the primary records During refragmentation and creation of secondary indices log records for the involved table are also sent to the fragment replicas being created In that case a transaction needs four times as many locks as the number of involved records Assuming all queries are for the affected table Summary If refragmentation is performed the number oflocks to be configured is Niocks 4x y 7000 2 2xy 3500 2x Otherwise the number of locks to be configured is Niocks 2x y 7000 2 xy 3500 4x Tuning NumberOfLocks Start with the default value Look for exceptions with the indicated error codes in the Enterprise Server log files Remember that under normal operations no ongoing refragmentation only half ofthe locks might be acquired by the client application To get information on allocated locks and locks in use use the following command hadbm resourceinfo locks Sun GlassFish Enterprise Server 2 1 Performance Tuning Guide January 2009 Tuning HADB Fo

Sun GlassFish Enterprise Server 21 Performance Tuning Guide

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