IV47866: WEBSPHERE MQ V7, QUEUE MANAGER ENDS UNEXPECTEDLY WITH AN FDC WITH PROBE ID HL214091 FROM AMQZMUC0.

Fix Pack 7.1.0.5 for WebSphere MQ V7.1
Fix Pack 7.1.0.6 for WebSphere MQ V7.1

APAR status

• Closed as program error.

Error description

• A WebSphere MQ v7 queue manager ends unexpectedly with FDCs
  being created. The first FDC has Probe Id HL214091 from process
  amqzmuc0. The FDC has:
   :
   Probe Id          :- HL214091
   Application Name  :- MQM
   Component         :- mllWriteLogPages
   SCCS Info         :- lib/logger/amqherr0.c, 1.21.2.1
   :
   Build Type        :- IKAP - (Production)
   Effective UserID  :- yyyy (mqm)
   Real UserID       :- yyyy (mqm)
   Program Name      :- amqzmuc0
   Addressing mode   :- 64-bit
   LANG              :- en_US
   Process           :- processid
   Thread            :- threadid
   QueueManager      :- queuemanager name
   UserApp           :- FALSE
   :
   Major Errorcode   :- hrcE_MQLP_NOSPACE
   Minor Errorcode   :- OK
   Probe Type        :- INCORROUT
   Probe Severity    :- 2
   Probe Description :- AMQ6125: An internal WebSphere MQ error
                        has occurred.
   FDCSequenceNumber :- 0
   .
   MQM Function Stack
   zmuThreadMain
   zmuLogIOTask
   mqlpgasn
   mllLoopWhilstDataToWrite
   mllWriteLogPages
   xcsFFST
   .
   MQM Trace History
   :
   -} WriteBuffers rc=hrcE_MQLP_NOSPACE
   :
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  It is unknown what causes this very rare problem and so it is
  not possible to identify who may be affected.
  
  Platforms affected:
  Windows,All Unix
  
  ****************************************************************
  PROBLEM SUMMARY:
  The MQ logger has mis-counted the log space in use. It is
  unclear why that has occurred. An extensive code investigation
  has revealed that FDC reporting can be improved; additional
  checks can be put in place to try and catch the problem earlier;
  and there are some issues in error handling cases of the logic
  involved.
  

Problem conclusion

• The following changes have been made :-
  
  1) Improved reporting of FDCs that report count inconsistencies:
  the FDC that was reported, failed to provide the "log bytes in
  use" value.
  
  2) Additional checking to try and catch any count discrepancy
  earlier. The complex nature of the log space reservation makes
  it difficult, if not impossible, to catch a discrepancy right at
  the point it occurs. However, the earlier we can catch it the
  more likely we are to get some further clues as to what may have
  gone wrong.
  
  3) Correction of logic problems discovered in the error handling
  cases, that could potentially give rise to incorrect log space
  accounting.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v7.1       7.1.0.6
  v7.5       7.5.0.5
  
  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 AIX V7

• Fixed component ID

  5724H7221

Applicable component levels

• R710 PSY

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