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IT05252: A WEBSPHERE MQ MFT AGENT GENERATES AN FFDC FILE REPORTING A CONCURRENTMODIFICATIONEXCEPTION

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APAR status

  • Closed as program error.

Error description

  • If an unexpected exception occurs within a WebSphere MQ Managed
    File Transfer agent, then a
    java.util.ConcurrentModificationException can occur. An FFDC
    file is generated by the agent containing the following
    information:
    
    Level: f750-FP-20131223-1239
    Time: 29/10/2014 14:43:37:333 GMT
    Thread: 147
    (TransferSender[414d5120514d434f524344315520202043e79a5374e30020
    ])
    Class: com.ibm.wmqfte.thread.FTEThread
    Method: uncaughtException
    Probe: FFDC_001
    Cause: java.util.ConcurrentModificationException
    java.util.ConcurrentModificationException
     at
    java.util.HashMap$AbstractMapIterator.checkConcurrentMod(HashMap
    .java:197)
     at
    java.util.HashMap$AbstractMapIterator.makeNext(HashMap.java:202)
     at java.util.HashMap$EntryIterator.next(HashMap.java:263)
     at java.util.HashMap$EntryIterator.next(HashMap.java:256)
     at
    com.ibm.wmqfte.wmqiface.WMQApiImpl.disconnectWMQConnections(WMQA
    piImpl.java:130)
     at
    com.ibm.wmqfte.thread.FTEThread.uncaughtException(FTEThread.java
    :91)
     at java.lang.Thread.uncaughtException(Thread.java:1241)
    

Local fix

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    This issue affects all users of WebSphere MQ Managed File
    Transfer v7.5 and v8.
    
    
    Platforms affected:
    MultiPlatform
    
    ****************************************************************
    PROBLEM DESCRIPTION:
    If a thread, running within a WebSphere MQ Managed File Transfer
    agent process, experienced an unexpected error then the agent
    would attempt to disconnect and destroy any connections to the
    WebSphere MQ agent queue manager that were associated with the
    thread. To do this, the code iterated over the map of all of the
    connections from the agent to its queue manager. When it found
    one associated with the thread that experienced the unexpected
    error, it attempted to remove it from the map. This resulted in
    a java.util.ConcurrentModificationException as the action of
    removing the connection from the map modified the map while the
    thread was iterating over it, which is not a permissible
    operation.
    

Problem conclusion

  • The WebSphere MQ Managed File Transfer code has been updated so
    that disconnected connections to a WebSphere MQ queue manager
    can be safely removed from the map of all connections held by
    the agent, preventing a
    java.util.ConcurrentModificationException from occurring.
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
    Version    Maintenance Level
    v7.5       7.5.0.5
    v8.0       8.0.0.2
    
    The latest available FTE maintenance can be obtained from
    'Fix List for WebSphere MQ File Transfer Edition 7.0'
    http://www-01.ibm.com/support/docview.wss?uid=swg27015313
    
    The latest available MQ maintenance can be obtained from
    'WebSphere MQ Recommended Fixes'
    http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006037
    
    If the maintenance level is not yet available information on
    its planned availability can be found in 'WebSphere MQ
    Planned Maintenance Release Dates'
    http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006309
    ---------------------------------------------------------------
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT05252

  • Reported component name

    WMQ MFT

  • Reported component ID

    5724H7242

  • Reported release

    750

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2014-10-29

  • Closed date

    2014-11-10

  • Last modified date

    2014-11-10

  • 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

    WMQ MFT

  • Fixed component ID

    5724H7242

Applicable component levels

  • R750 PSY

       UP

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Document Information

Modified date:
10 November 2014