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PI76705: ENABLE VERBOSEGC BY DEFAULT ON WEBSPHERE APPLICATION SERVER FOR Z/OS

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APAR status

  • Closed as new function.

Error description

  • Enable verboseGC by default on servers created using
    WebSphere Application Server for z/OS version 9.0.0.4.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:  All users of IBM WebSphere Application      *
    *                  Server for z/OS.                            *
    ****************************************************************
    * PROBLEM DESCRIPTION: Verbose garbage collection (verboseGC)  *
    *                      is disabled by default.                 *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    Starting in version 9.0.0.4 WebSphere Application Server
    for z/OS enables verboseGC by default for the Application
    Server, Node Agent, and Deployment Manager server types.
    This is a change in default behavior from previous releases
    wherein verboseGC is disabled by default for all server types.
    .
    "Verbose garbage collection" (verboseGC) is a setting in the
    Java virtual machine configuration for a server type, such
    as a Deployment Manager or Application Server.  When verboseGC
    is enabled (unset or set to true) in the server configration,
    WebSphere Application Server supplies the standard java option
    "-verbose:gc" to the java command line when launching the
    server.  The option directs the JVM to write verboseGC
    diagnostic data to native process streams, which on z/OS
    collect in JES job logs.
    .
    The new default verboseGC setting may be inappropriate for a
    particular server in your deployment.  To disable verboseGC
    on a server, disable (set to false) the "Verbose garbage
    collection" setting in the server's Java Virtual Machine
    configuration. Also, ensure that the Generic JVM Arguments
    field of the server's Java Virtual Machine configuration does
    not specify command-line argument "-verbose:gc".  After saving
    your changes to the configuration, verbose garbage collection
    will be disabled the next time the server is started.
    

Problem conclusion

  • VerboseGC diagnostic data is critical to troubleshooting
    memory and performance problems, and the overhead is generally
    very low.  APAR PI76705 enables verboseGC by default to ensure
    diagnostic data is immediately available when such problems
    occur.
                                  .
    APAR PI76705 is currently targeted for inclusion in fix pack
    9.0.0.4.  Please refer to the Recommended Updates page for
    delivery information:
    http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
    

Temporary fix

Comments

APAR Information

  • APAR number

    PI76705

  • Reported component name

    WEBSPHERE FOR Z

  • Reported component ID

    5655I3500

  • Reported release

    900

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2017-02-16

  • Closed date

    2017-03-16

  • Last modified date

    2017-03-16

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

  • 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

  • R900 PSY

       UP

[{"Business Unit":{"code":"BU053","label":"Cloud \u0026 Data Platform"},"Product":{"code":"SS7K4U","label":"WebSphere Application Server for z\/OS"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"900","Line of Business":{"code":"LOB36","label":"IBM Automation"}}]

Document Information

Modified date:
19 October 2021