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PH16983: USE TRIGGERDUMP WITH REQUEST=EXCLUSIVE INSTEAD OF SYSTEMDUMP

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APAR status

  • Closed as program error.

Error description

  • A Java core dump may be corrupt when generated during garbage
    collection.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:  All users of IBM WebSphere Application      *
    *                  Server                                      *
    ****************************************************************
    * PROBLEM DESCRIPTION: The generateSystemDump operation of     *
    *                      the JVM MBean may generate a dump       *
    *                      file containing inconsistent data.      *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    The generateSystemDump operation may generate a dump file
    containing inconsistent data whenever the thread which
    produces the dump executes while garbage collection operations
    are running, especially when heap memory is near exhaustion.
    For IBM SDKs, APAR PH16983 modifies generateSystemDump to
    specify the exclusive option to the JVM dump agent when
    triggering a system dump.  The exclusive option helps ensure
    the dump contains consistent data by scheduling the thread
    that produces the dump to wait for Java threads and garbage
    collection operations to halt/complete before writing the
    data.
    JVM MBean operations, including generateSystemDump, may be
    invoked indirectly via the Administrative Console or directly
    via the wsadmin utility to manually generate Java dumps and
    core files.
    To generate a system dump for <server> on <node> using the
    wsadmin utility:
    1. Start the wsadmin scripting client
    2. Invoke the generateSystemDump operation on a JVM MBean:
    2.a. Using Jacl:
    > set objectName [$AdminControl queryNames
    WebSphere:type=JVM,process=<server>,node=<node>,*]
    > $AdminControl invoke $objectName generateSystemDump
    2.b. Using Jython:
    > objectName = AdminControl.queryNames('WebSphere:type=JVM,
    process=<server>,node=<node>,*')
    > print AdminControl.invoke(objectName, 'generateSystemDump')
    To learn more about generating Java dumps and core files,
    visit the IBM Knowledge Center topic
    "Collecting Java dumps and core files using the administrative
    console" at URL:
    https://www.ibm.com/support/knowledgecenter/SSEQTP_9.0.5/com.ibm
    .websphere.base.doc/ae/utrb_dumpcore.html
    

Problem conclusion

  • Apply APAR PH16983 to specify the exclusive option to the dump
    agent when triggering a system dump on IBM JVMs.
    
    The fix for this APAR is currently targeted for inclusion in
    fix pack 9.0.5.2 and 8.5.5.17.  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

    PH16983

  • Reported component name

    WEBS APP SERV N

  • Reported component ID

    5724H8800

  • Reported release

    900

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2019-09-19

  • Closed date

    2019-09-30

  • Last modified date

    2019-10-09

  • 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

    WEBS APP SERV N

  • Fixed component ID

    5724H8800

Applicable component levels

  • R850 PSY

       UP

  • R900 PSY

       UP

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

Document Information

Modified date:
15 October 2021