IT43663: A duplicate message identifier (MsgId) is generated intermittently by the queue manager on Windows

APAR status

• Closed as program error.

Error description

• Message identifiers generated by a queue manager should be
  unique.
  
  This APAR addresses a problem where message producers were
  putting messages to queues and topics, and under heavy load the
  queue manager intermittently assigned duplicate message
  identifiers to the put messages.
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Those relying on unique message identifiers across multiple
  queue and topics on Windows
  
  
  Platforms affected:
  Windows
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  When applications were executed which concurrently put messages
  to both queues and topics, a timing window existed where a queue
  manager could use the same message identifiers for multiple
  messages.
  

Problem conclusion

• The MQ queue manager's message identifier allocation logic has
  been correct to prevent this issue.
  
  This APAR fix is specific to queue managers on Windows. See
  related APAR IT36755 for a similar fix on Unix/Linux queue
  managers
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v9.2 LTS   9.2.0.20
  v9.3 LTS   9.3.0.15
  v9.x CD    9.3.4
  
  The latest available maintenance can be obtained from
  'IBM MQ Recommended Fixes'
  https://www.ibm.com/support/pages/recommended-fixes-ibm-mq
  
  If the maintenance level is not yet available information on
  its planned availability can be found in 'IBM MQ
  Planned Maintenance Release Dates'
  https://ibm.biz/mqplannedmaintenance
  
  ---------------------------------------------------------------
  

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

  MQ BASE V9.2

• Fixed component ID

  5724H7281

Applicable component levels