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PM16028: DRS THREADS COME FROM THE DEFAULT THREAD POOL, INSTEAD OF FROM A NAMED THREAD POOL SPECIFIC TO DRS.

A fix is available

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APAR status

  • Closed as program error.

Error description

  • DRS consumes threads from the default thread pool for processing
    incoming messages. It is difficult to tell which thread pool
    threads belong to DRS.  DRS should have its own named thread
    pool.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:  All users of IBM WebSphere Application      *
    *                  Server V7.0 using Data Replication          *
    *                  Services (DRS).                             *
    ****************************************************************
    * PROBLEM DESCRIPTION: Threads from the "Default" thread       *
    *                      pool become exhausted preventing        *
    *                      DRS or other users of the pool          *
    *                      from obtaining a thread.                *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    DRS uses threads from the "Default" thread pool for
    deserializing replication messages, passing messages to DRS
    consumers and creating servant change listeners on zOS.  In a
    high volume environment DRS may consumer a majority of the
    threads and prevent other application server components from
    obtaining a thread from the pool.
    

Problem conclusion

  • DRS has been modified to create its own thread pool at server
    startup.  The thread pool will be used exclusively by DRS and
    its consumers. This APAR introduces 3 JVM custom properties
    to set the minimum and maximum size of the thread pool and set
    the growable flag:
    
    DRS_THREADPOOL_MINSIZE default is 40
    DRS_THREADPOOL_MAXSIZE default is 100
    DRS_THREADPOOL_ISGROWABLE default false
    
    APAR PM16028 requires changes to documentation.
    
    NOTE: Periodically, we refresh the documentation on our
    Web site, so the changes might have been made before you
    read this text. To access the latest on-line
    documentation, go to the product library page at:
    
    http://www.ibm.com/software/webservers/appserv/library
    
    The following Change to the WebSphere Application
    Server Version 7.0 Information Center
    will be made available in October 2010.
    
    Step 3 in the topic "Replicating data across application
    servers in a cluster" will be updated to include the
    following information:
    
    Starting with Fix Pack 7.0.0.13, the replication service
    uses threads that are obtained from the DRS thread pool
    for various tasks, including processing messages.
    Previously, the replication service obtained threads from
    the default thread pool. When the application server
    starts up, the default maximum thread pool size for the
    DRS thread pool is 100 threads. However, this thread pool
    size might not be sufficient to enable the replication
    service to obtain enough threads from the pool to process
    all of the incoming replication messages. The number of
    incoming messages is influenced by the number of
    application servers in the domain and the number of
    replication domain consumers on each application server.
    The number of messages to be processed increases as the
    number of application servers in the domain increases,
    the number of replication consumers increases, or both.
    
    Persistent data that is not being replicated to the
    application servers when the application server starts
    up might indicate that you need to increase the setting
    for the maximum thread pool size. The maximum size of the
    DRS thread pool set to 100 is usually sufficient. However,
    in very large topologies, you might need to set the
    maximum thread pool size to a value that is greater than
    100.
    
    Table 1. DRS thread pool custom properties.
    
    You can set the properties of the DRS thread pool through
    the following Java virtual machine custom properties.
    Property name               Default value
    DRS_THREADPOOL_MINSIZE       40
    DRS_THREADPOOL_MAXSIZE       100
    DRS_THREADPOOL_ISGROWABLE       false
    
    For more information, see the documentation about Java
    virtual machine custom properties.
    
    APAR PM16028 is currently targeted for inclusion in Service
    Level (Fix Pack) 7.0.0.13 of WebSphere Application Server V7.0.
    
    Please refer to URL:
    //www.ibm.com/support/docview.wss?rs=404&uid=swg27006970
    for Fix Pack availability.
    

Temporary fix

Comments

APAR Information

  • APAR number

    PM16028

  • Reported component name

    WEBSPHERE FOR Z

  • Reported component ID

    5655I3500

  • Reported release

    700

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2010-06-07

  • Closed date

    2010-07-28

  • Last modified date

    2010-11-03

  • APAR is sysrouted FROM one or more of the following:

    PM16027

  • APAR is sysrouted TO one or more of the following:

Fix information

  • Fixed component name

    WEBSPHERE FOR Z

  • Fixed component ID

    5655I3500

Applicable component levels

  • R700 PSY UK61114

       UP10/10/21 P F010

Fix is available

  • Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.

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Document Information

Modified date:
10 February 2022