IT18666: Queue manager ends unexpectedly due to memory exception FDC probe XC130003 under apiCheckpointMemoryObjects

APAR status

• Closed as program error.

Error description

• The queue manager ends unexpectedly.  The issue is recorded in
  FDC records with probe XC130003 xehExceptionHandler.  The call
  stack includes apiCheckpointMemoryObjects and mqlWriteLogRecord.
   The process is amqzmuc0.
  
  Probe Id          :- XC130003
  Component         :- xehExceptionHandler
  Program Name      :- amqzmuc0
  Arith1            :- 11 (0xb)
  Comment1          :- SIGSEGV: address not mapped((nil))
  
  MQM Function Stack
  zmuThreadMain
  zmuCheckpointTask
  alsCheckPointLoop
  aocPerformCheckpoint
  apiCheckpointMemoryObjects
  almLogIt
  hlgWriteLogRecord
  mqlWriteLogRecord
  xcsFFST
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Queue managers that are members of a cluster.
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  The queue manager's checkpoint code writes data to the queue
  manager's logs, including some MQ internal data relating to the
  cluster transmission queue(s) in use for each cluster channel.
   In this case some data that was logically "deleted" was being
  written to the logs, but should not have been.  Because of a
  code error, a null pointer was used and this resulted in a
  memory exception and the ending of the amqzmuc0 process which
  contains crucial queue manager internal operations.  The queue
  manager then ended immediately because of this.
  

Problem conclusion

• The MQ code has been corrected so that logically "deleted"
  objects are not written to the logs during checkpoint
  processing.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v7.5       7.5.0.8
  
  The latest available 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 BASE MULTIP

• Fixed component ID

  5724H7241

Applicable component levels