IT24593: Message may be discarded when using async consume to consume messages outside of syncpoint

APAR status

• Closed as program error.

Error description

• When the IBM MQ V8 Client uses asynchronous consume to get
  messages outside syncpoint there is a timing window in
  which the callback can return MQRC_NO_MSG_AVAILABLE (RC=2033)
  without delivering a pending message.
  
  The problem is more likely to occur when the callback function
  takes longer than the gmo.WaitInterval to process the message.
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Users using MQ client with asynchronous consume with MQGMO_WAIT
  and MQGMO_NO_SYNCPOINT options.
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  An MQ client was retrieving messages asynchronously and
  de-registered the callback while a message was pending delivery.
  
  A defect in the MQ code caused the callback to return
  MQRC_NO_MSG_AVAILABLE (RC=2033) without delivering the pending
  message.
  

Problem conclusion

• The defect has been fixed to ensure that pending message will be
  delivered.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v8.0       8.0.0.12
  v9.0 LTS   9.0.0.7
  
  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

  5724H7251

Applicable component levels