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PM21935: SIB MESSAGE DRIVEN BEANS STOP PROCESSING MESSAGES DUE TO A DEADLOCK BETWEEN THREADS WHEN A FULL SET OF MDBS ARE 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
6.1.0.37: Java SDK 1.5 SR12 FP3 Cumulative Fix for WebSphere
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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You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • The 'Maximum concurrent MDB invocations per endpoint' option
    on a Service Integration Bus activation specification controls
    the number of MDB instances which the bus will run in parallel
    to process messages.  When a full set of MDBs is running, the
    activation specification briefly stops message delivery.  There
    is a small chance that the activation specification can deadlock
    at this point, preventing further delivery of messages.
      When this problem happens, a javacore or thread dump of the
    application server will show two threads deadlocked with stacks
    similar to the ones below:
    .
    "Thread : 1"
      at com/ibm/ws/sib/processor/impl/JSLocalConsumerPoint
         .internalStop(JSLocalConsumerPoint.java:3241)
      at com/ibm/ws/sib/processor/impl/JSLocalConsumerPoint
         .stop(JSLocalConsumerPoint.java:3230)
      at com/ibm/ws/sib/processor/impl/ConsumerSessionImpl
         .stop(ConsumerSessionImpl.java:847)
      at com/ibm/ws/sib/ra/inbound/impl/SibRaSingleProcessListener$
         SibRaWork.workAccepted(SibRaSingleProcessListener.java:662)
      at com/ibm/ejs/j2c/work/WorkProxy.<init>(WorkProxy.java:194)
      at com/ibm/ejs/j2c/work/WorkManagerImpl
         .scheduleWork(WorkManagerImpl.java:356)
      at com/ibm/ws/sib/ra/inbound/impl/SibRaSingleProcessListener$
         SibRaWork.schedule(SibRaSingleProcessListener.java:546)
      at com/ibm/ws/sib/ra/inbound/impl/SibRaSingleProcessListener
         .internalConsumeMessages(SibRaSingleProcessListener.java:
         377(Compiled Code))
      at com/ibm/ws/sib/ra/inbound/impl/SibRaListener$
         $AsynchResumeCallbackImpl.run(SibRaListener.java:1055)
      at com/ibm/ws/util/ThreadPool$Worker.run(ThreadPool.java:
         1497(Compiled Code))
    .
    "Thread : 2"
      at com/ibm/ws/sib/processor/impl/AsynchConsumer
         .processMsgs(AsynchConsumer.java:105)
      at com/ibm/ws/sib/processor/impl/JSLocalConsumerPoint
         .processQueuedMsgs(JSLocalConsumerPoint.java:2161
         2161(Compiled Code))
      at com/ibm/ws/sib/processor/impl/JSLocalConsumerPoint
         .runAsynchConsumer(JSLocalConsumerPoint.java:
         2712(Compiled Code))
      at com/ibm/ws/sib/processor/impl/JSLocalConsumerPoint$
         AsynchThread.run(JSLocalConsumerPoint.java:2931)
      at com/ibm/ws/util/ThreadPool$Worker.run(ThreadPool.java:
         1497(Compiled Code))
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:  Users of the default messaging provider     *
    *                  for IBM WebSphere Application Server using  *
    *                  WebSphere Virtual Enterprise or             *
    *                  WebSphere Extended Deployment               *
    ****************************************************************
    * PROBLEM DESCRIPTION: Deadlock in messaging engine whilst     *
    *                      processing at the configured maximum    *
    *                      concurrent endpoints, and MDB           *
    *                      throttling is active.                   *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    There are two throttling systems active for default
    messaging provider message-driven beans, when MDB throttling is
    enabled in WebSphere Virtual Enterprise.
    
    These two systems can disagree on the desired state of the
    MDB, and might suspend and resume over the top of each other.
    In some cases, causing deadlock. In other cases, causing an
    unexpectedly large number of concurrent MDB instances.
    

Problem conclusion

  • The code has been altered to ensure that the two throttling
    systems operate correctly. An MDB will only be active when both
    throttling mechanisms agree that it should be.
    
    With the fix for this APAR applied, the maximum number of
    threads that can be active for an MDB concurrently (per
    endpoint) is defined by the "Maximum concurrent endpoints"
    setting of the activation specification. WebSphere Extended
    Deployment might further limit the number of concurrent MDB
    instances below this number (while it cannot extend the number
    of current MDB instances beyond this limit).
    
    The fix for this APAR is currently targeted for inclusion in
    fix pack 6.1.0.37, and 7.0.0.15.  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

    PM21935

  • Reported component name

    PLAT MSG COM

  • Reported component ID

    620600101

  • Reported release

    200

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2010-09-03

  • Closed date

    2010-10-29

  • Last modified date

    2010-10-29

  • 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

    PLAT MSG COM

  • Fixed component ID

    620600101

Applicable component levels

  • R200 PSY

       UP



Document information

More support for: WebSphere Application Server
Service Integration Technology

Software version: 6.1

Reference #: PM21935

Modified date: 29 October 2010