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PI52434: IN A CLUSTERED ENVIRONMENT WITH M2M SESSION REPLICATION, NON-SERIALIZED SESSION ACCESS CAN CAUSE NULLPOINTEREXCEPTION

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APAR status

  • Closed as program error.

Error description

  • Under high load in a Clustered environment with session
    replication, a race condition might occur, when two application
    requests try to access the same session.
    
    This can result in a NullpointerException.
    

Local fix

  • n/a
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:  All users of IBM WebSphere Application      *
    *                  Server version 7.0, 8.0 and 8.5.5           *
    *                  implementing asynchronous threads in a M2M  *
    *                  environment.                                *
    ****************************************************************
    * PROBLEM DESCRIPTION: A NullPointerException may be thrown    *
    *                      when                                    *
    *                      asynchronous threads attempt to access  *
    *                      a                                       *
    *                      session from the replication domain     *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    If two asynchronous threads attempt to access the same session
    simultaneously, and the session needs to be retrieved from the
    replication domain of a M2M replicated environment, a
    NullPointerException may result even if Serialized Session
    Access
    is enabled.
    

Problem conclusion

  • When Serialized Session Access is enabled, the session
    retrievals from the replication domain are now synchronized to
    accommodate simultaneous access from asynchronous threads.
    
    These changes are targeted for inclusion in fix packs
    7.0.0.41, 8.0.0.13 and 8.5.5.10  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

    PI52434

  • Reported component name

    WEBS APP SERV N

  • Reported component ID

    5724H8800

  • Reported release

    800

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2015-11-13

  • Closed date

    2016-01-27

  • Last modified date

    2016-08-18

  • 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

  • R700 PSY

       UP

  • R800 PSY

       UP

  • R850 PSY

       UP



Document information

More support for: WebSphere Application Server
General

Software version: 8.0

Reference #: PI52434

Modified date: 18 August 2016