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

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 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

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