IC73413: POTENTIAL FOR MESSAGE LOSS WHEN MICRO BROKER CONNECTS TO AN WMQ V7.0 QM AND THE QM IS QUIESCED DURING A MESSAGE GET

WebSphere MQ V7.0 Fix Pack 7.0.1.5
WebSphere MQ V7.0.1 for i5/OS Fix Pack 7.0.1.5

APAR status

• Closed as program error.

Error description

• When using Lotus Expeditor micro broker, if the queue manager
  that micro broker is connected to is quiesced and the WebSphere
  MQ JMS client which runs within micro broker is attempting to
  get a message as the shutdown is triggered, that message can be
  lost.
  
  This happens intermittently, and only when Lotus Expeditor
  micro broker uses the WebSphere MQ v7 JMS classes to connect to
  a WebSphere MQ V7.0 queue manager.
  
  It is not seen when connecting to an WebSphere MQ V6 queue
  manager.
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  This issue affects users of synchronous receive calls in
  V7.0 WebSphere MQ classes for JMS (Java Message Service).
  
  Platforms affected:
  All Distributed (iSeries, all Unix and Windows) +Java
  ****************************************************************
  PROBLEM SUMMARY:
  If the V7.0 WebSphere MQ classes for JMS client application is
  in the process of receiving a message from WebSphere MQ, for
  example:
  
  MessageConsumer.receive()
  
  and the WebSphere MQ queue manager is stopping or stopped,
  occasionally the call for receiving the message returns
  "null", giving the perception that there are no messages on the
  queue, instead of an exception.  Based on this return value,
  Lotus Expeditor micro broker takes a code path to delete
  messages in its persistence store, which can result in message
  loss.
  
  This message loss does not occur within the WebSphere MQ
  product itself. The implications of returning "null" instead of
  a JMSException in this case led to a message loss in Lotus
  Expeditor micro broker.
  

Problem conclusion

• The code fix for this issue ensures that V7.0 WebSphere MQ
  classes for JMS throws a JMS exception with a linked exception
  having the reason code MQRC_Q_MGR_QUIESCING under these
  circumstances. The MessageConsumer.receive() call will no longer
  return "null" while the queue manager is quiescing, ensuring
  that Lotus Expeditor micro broker handles this exception like
  any other regular connectivity error.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
                     v7.0
  Platform           Fix Pack 7.0.1.5
  --------           --------------------
  Windows            U200324
  AIX                U839183
  HP-UX (PA-RISC)    U839621
  HP-UX (Itanium)    U839626
  Solaris (SPARC)    U839622
  Solaris (x86-64)   U839628
  iSeries            tbc_p700_0_1_5
  Linux (x86)        U839623
  Linux (x86-64)     U839627
  Linux (zSeries)    U839624
  Linux (Power)      U839625
  
  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

  WMQ WINDOWS V7

• Fixed component ID

  5724H7220

Applicable component levels

• R700 PSY

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