IBM Support

PM16861: DEADLOCKED THREADS WITH SESSION TRACING ACTIVE

Fixes are available

7.0.0.15: WebSphere Application Server V7.0 Fix Pack 15 for AIX
7.0.0.15: Java SDK 1.6 SR9 Cumulative Fix for WebSphere Application Server
7.0.0.15: WebSphere Application Server V7.0 Fix Pack 15 for HP-UX
7.0.0.15: WebSphere Application Server V7.0 Fix Pack 15 for IBM i
7.0.0.15: WebSphere Application Server V7.0 Fix Pack 15 for Linux
7.0.0.15: WebSphere Application Server V7.0 Fix Pack 15 for Solaris
7.0.0.15: WebSphere Application Server V7.0 Fix Pack 15 for Windows
7.0.0.17: WebSphere Application Server V7.0 Fix Pack 17
7.0.0.17: Java SDK 1.6 SR9 FP1 Cumulative Fix for WebSphere Application Server
7.0.0.19: WebSphere Application Server V7.0 Fix Pack 19
7.0.0.21: WebSphere Application Server V7.0 Fix Pack 21
7.0.0.23: WebSphere Application Server V7.0 Fix Pack 23
7.0.0.25: WebSphere Application Server V7.0 Fix Pack 25
7.0.0.27: WebSphere Application Server V7.0 Fix Pack 27
7.0.0.29: WebSphere Application Server V7.0 Fix Pack 29
6.1.0.47: WebSphere Application Server V6.1 Fix Pack 47
7.0.0.31: WebSphere Application Server V7.0 Fix Pack 31
7.0.0.27: Java SDK 1.6 SR13 FP2 Cumulative Fix for WebSphere Application Server
7.0.0.33: WebSphere Application Server V7.0 Fix Pack 33
7.0.0.35: WebSphere Application Server V7.0 Fix Pack 35
7.0.0.37: WebSphere Application Server V7.0 Fix Pack 37
7.0.0.39: WebSphere Application Server V7.0 Fix Pack 39
7.0.0.41: WebSphere Application Server V7.0 Fix Pack 41
7.0.0.43: WebSphere Application Server V7.0 Fix Pack 43
7.0.0.45: WebSphere Application Server V7.0 Fix Pack 45
6.1.0.39: Java SDK 1.5 SR12 FP4 Cumulative Fix for WebSphere Application Server
6.1.0.41: Java SDK 1.5 SR12 FP5 Cumulative Fix for WebSphere Application Server
6.1.0.43: Java SDK 1.5 SR13 Cumulative Fix for WebSphere Application Server
6.1.0.45: Java SDK 1.5 SR14 Cumulative Fix for WebSphere Application Server
6.1.0.47: Java SDK 1.5 SR16 Cumulative Fix for WebSphere Application Server
7.0.0.19: Java SDK 1.6 SR9 FP2 Cumulative Fix for WebSphere Application Server
7.0.0.21: Java SDK 1.6 SR9 FP2 Cumulative Fix for WebSphere
7.0.0.23: Java SDK 1.6 SR10 FP1 Cumulative Fix for WebSphere
7.0.0.25: Java SDK 1.6 SR11 Cumulative Fix for WebSphere Application Server
7.0.0.27: Java SDK 1.6 SR12 Cumulative Fix for WebSphere Application Server
7.0.0.29: Java SDK 1.6 SR13 FP2 Cumulative Fix for WebSphere Application Server
7.0.0.45: Java SDK 1.6 SR16 FP60 Cumulative Fix for WebSphere Application Server
7.0.0.31: Java SDK 1.6 SR15 Cumulative Fix for WebSphere Application Server
7.0.0.35: Java SDK 1.6 SR16 FP1 Cumulative Fix for WebSphere Application Server
7.0.0.37: Java SDK 1.6 SR16 FP3 Cumulative Fix for WebSphere Application Server
7.0.0.39: Java SDK 1.6 SR16 FP7 Cumulative Fix for WebSphere Application Server
7.0.0.41: Java SDK 1.6 SR16 FP20 Cumulative Fix for WebSphere Application Server
7.0.0.43: Java SDK 1.6 SR16 FP41 Cumulative Fix for WebSphere Application Server
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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    *
    *                 V7.0 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 PM16861 is currently targeted for inclusion in Service
    Level (Fix Pack) 7.0.0.15 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

    PM16861

  • 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

    2010-06-18

  • Closed date

    2010-09-23

  • Last modified date

    2011-06-26

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

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

    PM42424

Fix information

  • Fixed component name

    WEBSPHERE FOR Z

  • Fixed component ID

    5655I3500

Applicable component levels

  • R700 PSY UK65060

       UP11/03/04 P F103

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: 7.0

Reference #: PM16861

Modified date: 26 June 2011