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PM42424: DEADLOCKED THREADS WITH SESSION TRACING ACTIVE

A fix is available

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You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • With session tracing active, customers may experience a deadlock
    in threads attempting to write out trace entries.  The
    deadlocked threads will be:
    .
    java/lang/String.valueOf
    java/lang/StringBuffer.append
    com/ibm/ws/session/utils/LRUHashMap$CacheEntryWrapper.toString
    java/text/MessageFormat.subformat
    java/text/MessageFormat.format
    ..
    and:
    .
    com/ibm/ws/session/store/common/BackedHashMap.superRemove
    com/ibm/ws/session/store/mtm/MTMHashMap.superRemove
    com/ibm/ws/session/store/mtm/MTMHashMap.removePersistedSession
    com/ibm/ws/session/store/common/BackedStore.removeSession
    ...
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED: Users of IBM WebSphere Application Server    *
    *                 V6.1 who have enabled session trace          *
    *                 may experience a rare deadlock.              *
    *                                                              *
    ****************************************************************
    * PROBLEM DESCRIPTION: A deadlock may occur with session       *
    *                      tracing enabled.                        *
    *                                                              *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    When session tracing is enabled, extra session information
    is logged under synchronization. Under some rare timing
    sequence when multiple threads are accessing a given session
    simultaneously, a deadlock might result.
    

Problem conclusion

  • Code changes have been made to the trace messages to avoid the
    synchronization points that could deadlock.
    
    APAR PM42424 is currently targeted for inclusion in Service
    Level (Fix Pack) 6.1.0.39 of WebSphere Application Server V6.1.
    
    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

    PM42424

  • Reported component name

    WEBSPHERE FOR Z

  • Reported component ID

    5655I3500

  • Reported release

    610

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2011-06-26

  • Closed date

    2011-06-29

  • Last modified date

    2011-08-01

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

    PM16861

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

Modules/Macros

  • BBGUBINF BBOUBINF
    

Fix information

  • Fixed component name

    WEBSPHERE FOR Z

  • Fixed component ID

    5655I3500

Applicable component levels

  • R610 PSY UK69361

       UP11/07/16 P F107

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.



Document information

More support for: WebSphere Application Server for z/OS
General

Software version: 6.1

Reference #: PM42424

Modified date: 01 August 2011