IT32681: MQ clustering allows an out-of-order internal cluster subscription to incorrectly replace a newer one

APAR status

• Closed as program error.

Error description

• A full repository QMGR within a cluster attempted to set
  PUT(ENABLED) on a queue but received the error "AMQ9428 mismatch
  subscription is issued by partial repository QMGR". The update
  did not propagate to a partial repository QMGR because of this
  error.
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Users of Queue Manager Clusters
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  Changes to a cluster object were not correctly propagated to a
  partial repository that is connected to a full repository by
  multiple channels
  following a REFRESH CLUSTER command.
  
  A partial repository remade its internal cluster subscriptions
  for a cluster queue it had accessed, however the Programmable
  Command Format (PCF) message was delayed reaching the full
  repositories. During this delay, REFRESH CLUSTER was issued on
  the partial repository queue manager and the command messages
  associated with the refresh arrived at the full repository using
  a different channel ahead of the internal cluster subscription
  message, causing the original internal cluster subscription for
  the queue to be deleted.
  When the partial repository accessed the queue again, new
  internal cluster subscriptions were created. Later however, when
  the delayed internal cluster subscription message arrived at the
  full repository, it caused the newest internal cluster
  subscription to be replaced by this old subscription.
  
  This resulted in the partial repository queue manager rejecting
  updates to the queue as reported by error AMQ9428 (if running on
  distributed platforms) or CSQ428E (if the running on z/OS).
  

Problem conclusion

• The product code is changed to correctly determine the age of
  internal cluster subscriptions, and prevent the newest ones
  being replaced with an older subscription for the specific
  object(s) in question.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v9.1 LTS   9.1.0.10
  v9.2 LTS   9.2.0.4
  v9.x CD    9.2.5
  
  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

  IBM MQ BASE MP

• Fixed component ID

  5724H7271

Applicable component levels