IT19598: AMQ9510 reason code 2150 issued for SYSTEM.CLUSTER.COMMAND.QUEUE

IBM MQ for HP NonStop Server V8.1 Fix Pack 8.1.0.6

APAR status

• Closed as program error.

Error description

• After altering the queue manager's CCSID, the following messages
  might be issued from the clustering component of the queue
  manager.  The queue manager will eventually terminate, unless it
  is ended manually.  However, restarting the queue manager
  resolves the issue permanently.
  
  The errors relate to character data within internal MQ command
  messages used by the clustering component of the queue manager.
  
  AMQ9510: Messages cannot be retrieved from a queue.
  EXPLANATION:
  The attempt to get messages from queue
  'SYSTEM.CLUSTER.COMMAND.QUEUE' on queue manager 'QMNAME' failed
  with reason code 2150.
  
  AMQ6174: The dynamically loadable shared library
  '/var/mqm/exits64/MQADMIN_r' was not found.
  
  AMQ9448: Repository manager failed.  Retry in 10 minutes, queue
  manager will terminate in 7050 minutes.
  
  After the fix for IT15735, the sequence of errors is different,
  and updates to local cluster cache state are dropped,
  incorrectly.  If the queue manager has a dead letter queue, one
  or more messages will be put there, but there is no action the
  user can then take to handle those messages.
  
  Additionally it is possible this problem will be seen for
  certain types of internal MQ cluster state data arriving from
  remote cluster queue managers to this one.
  

Local fix

• Correct the CCSID, if it was wrongly typed.
  Restart the queue manager so that the same CCSID is used
  throughout the queue manager, including the repository manager
  program.
  

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Users who alter their QMGR CCSID, or (they cannot control this)
  receive internal cluster state messages with unconvertible
  characters from remote systems.
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  The errors relate to character data within internal MQ command
  messages used by the clustering component of the queue manager.
  
  The cluster repository manager program (amqrrmfa) gets these
  messages from the SYSTEM.CLUSTER.COMMAND.QUEUE using MQGET with
  MQGMO_CONVERT.
  
  Messages will be put containing character fields encoded with
  the new CCSID.
  
  However, by design amqrrmfa (as with all application programs
  that connected before the change in the CCSID) will have cached
  the previous value of the CCSID at the time it connected.
  Therefore MQGET tries to convert the messages.
  
  If there is a defined conversion from the new CCSID to the
  previous (cached) CCSID, this will be likely to succeed.  But
  even so, there are some byte sequences that will not convert
  successfully.
  
  If the user has used unconvertible byte sequences in fields such
  as queue or channel descriptions, then these will cause the
  conversion to fail with reason codes such as 2150
  MQRC_DBCS_ERROR.
  
  At this point the behaviour is different at different fix packs:
  At levels not including the fix for IT15735: message at the top
  of the queue became a poison message, and caused the queue
  manager to end after a prolonged period where it is retried
  without success.
  At levels including the fix for IT15735: the message at the top
  of the queue is moved to the DLQ, if one is defined.  The
  benefit is that the message is no longer a poison message.  But
  the downside is that that update was not made to the local
  cluster cache.  In the worst case this resulted in queues
  becoming expired and so invisible to applications.
  

Problem conclusion

• The MQ queue manager code has been updated with additional logic
  to handle the situation at the point when 2150 MQRC_DBCS_ERROR
  is returned from MQGET.
  
  The field(s) which might contain unconvertible characters will
  be blanked out and the conversion will be retried.  If the
  conversion succeeds, the code can proceed to store that update
  with a blank description.  Error messages AMQ6174 and AMQ9880
  will be written, to inform the administrator.
  
  If the message is still unconvertible then it will be moved to
  the Dead Letter Queue and an error message will be written.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v7.5       7.5.0.9
  v8.0       8.0.0.8
  v9.0 CD    9.0.4
  v9.0 LTS   9.0.0.2
  
  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:

  PI82623 IT33905

Fix information

• Fixed component name

  WMQ BASE MULTIP

• Fixed component ID

  5724H7241

Applicable component levels

• R750 PSY

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