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PI65836: JAVACORES CONTINUOUSLY CREATED ON A HUNG THREAD

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You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • When com.ibm.websphere.threadmonitor.dump.java is set to true
    and if com.ibm.websphere.threadmonitor.dump.java.track is NOT
    set then by default a java thread dump is created continuously
    at the default hung thread detection time interval (default 3
    mins). So basically it will continuously produce java thread
    dumps every minute while the thread remains hung.
    
    In customer situation the hung thread never recovers and as a
    result a java thread dump is produced every 3 minutes and
    fills up gigabytes of storage.
    

Local fix

  • You can set
    com.ibm.websphere.threadmonitor.dump.java to 1
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:  All users of IBM WebSphere Application      *
    *                  Server                                      *
    ****************************************************************
    * PROBLEM DESCRIPTION: The hung thread detection system        *
    *                      repeatedly dumps javacores for the      *
    *                      same hung thread                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    The WebSphere Application Server thread monitor allows users
    to track hung threads by periodically dumping a javacore as
    long as the thread is detected as hung, using the
    com.ibm.websphere.threadmonitor.dump.java.track property.
    If this property is unset, the default value is set to be
    identical to the value of
    com.ibm.websphere.threadmonitor.dump.java.  If the property is
    set to "true", the thread monitor sets those properties to the
    maximum integer value, so a thread hung for a long period of
    time would cause javacores to be thrown basically
    indefinitely.
    Users who had used this property on previous editions of
    WebSphere Application Server would have been likely to use the
    "true" value, as the property utilized boolean values in its
    original incarnation, but since the "track" property did not
    exist, they would have only had one javacore thrown per thread.
    

Problem conclusion

  • The default value of the "track" property was modified so that
    if left unset, only one javacore would be thrown for a single
    hung thread.
    
    The fix for this APAR is currently targeted for inclusion in
    fix packs 8.5.5.12 and 9.0.0.3.  Please refer to the
    Recommended Updates page for delivery information:
    http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
    

Temporary fix

  • As a workaround, users can set the system property
    com.ibm.websphere.threadmonitor.dump.java.track to "1".
    

Comments

APAR Information

  • APAR number

    PI65836

  • Reported component name

    WEBS APP SERV N

  • Reported component ID

    5724H8800

  • Reported release

    850

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2016-07-13

  • Closed date

    2016-11-22

  • Last modified date

    2016-11-22

  • 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":"850","Line of Business":{"code":"LOB36","label":"IBM Automation"}}]

Document Information

Modified date:
14 October 2021