IT27810: Window for message loss or duplication if sender channel disconnects and reconnects during commit processing

APAR status

• Closed as program error.

Error description

• A small timing window exists with the potential for message loss
  or duplication if sender channel disconnects abnormally and
  reconnects during commit processing, for example due to network
  disruption or a forceful termination of the sender channel
  process.
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Users sending persistent messages, or non-persistent messages
  with NPMSPEED(NORMAL) on a channel between two queue managers
  are potentially affected.
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  A timing condition exists where an abnormal termination of a
  channel and subsequent channel retry could lead to loss of
  integrity to the transaction used to move a batch of messages
  from the transmission queue on one queue manager to the target
  queue manager, as a consequence messages in a batch could be
  lost or duplicated.
  

Problem conclusion

• Logic has been added to channels to ensure that the internal
  resources that are used to track the transaction used to
  transfer a batch of messages maintain consistency.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v8.0       8.0.0.12
  v9.0 LTS   9.0.0.6
  v9.1 CD    9.1.2
  v9.1 LTS   9.1.0.2
  
  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:

Fix information

• Fixed component name

  IBM MQ BASE MP

• Fixed component ID

  5724H7251

Applicable component levels