IT11879: NON-PERSISTENT, NON TRANSACTED MSGS LOST UNDER NORMAL RUNNING CONDITIONS

APAR status

• Closed as program error.

Error description

• When running in the WebSphere Application Server Liberty Profile
  using the IBM MQ messaging provider, messages sent using a
  MessageProducer created from a JMSContext intermittently fail to
  be processed. The message driven bean (MDB) which is expected to
  process these message is never invoked. No error messages are
  seen at either the client or Queue Manager.
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  This issue affects users of the IBM MQ v8 Resource Adapter who
  have applications which use a MessageProducer created from a
  JMSContext to send messages.
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  The IBM MQ v8 Resource Adapter provides an implementation of a
  JMSContext that can be used by application servers. This
  implementation utilises a number of internal objects to maintain
  information about the state of a JMSContext.  One of these
  internal objects, known as the internal message producer, tracks
  whether usage of the JMSContext should be transacted or
  non-transacted.
  
  This internal message producer was only created when the very
  first MessageProducer for that JMSContext was created.  If at
  this point, the application server decided to enlist the
  JMSContext in a transaction,  then the internal message producer
  was set to send messages inside a transaction. If there was no
  transaction active, then the internal message producer was set
  up to send messages outside of a transaction.
  
  When this JMSContext was closed and returned to the connection
  pool by the application server, the internal message producer
  was not cleared.  The result of this was that the transacted
  state of the internal message producer was cached for the
  lifetime of the JMSContext. When the JMSContext was removed from
  the connection pool and given to an application for re-use, the
  cached transactional state of the internal message producer
  resulted in the following behaviour:
  
   - If the first time the JMSContext was used to create a
  MessageProducer there was a transaction in progress, then the
  transactional state of the internal message producer was set as
  "transacted".   If subsequent usage of the JMSContext was
  non-transacted, then the MQ resource adapter would incorrectly
  send messages inside a unit of work, resulting in unexpected
  behaviour.
  
   - If the first time the JMSContext was used to create a
  MessageProducer there were no transactions in progress, then the
  transactional state of the internal message producer was set as
  "non-transacted". As this value was cached, all subsequent
  MessageProducers created from the JMSContext would be marked as
  "non-transacted", even if the JMSContext was being used inside
  of a transaction - this could cause the MQ resource adapter to
  incorrectly send messages outside of a transaction, again
  resulting in unexpected behaviour.
  

Problem conclusion

• The IBM MQ resource adapter has been updated so that the
  internal message producer is cleared when an application has
  finished using a JMSContext and has returned it to the
  application server's connection pool. The next time the
  JMSContext is used, the internal message producer is recreated
  and the transactional state is set correctly.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v8.0       8.0.0.4
  
  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 BASE MULTIP

• Fixed component ID

  5724H7251

Applicable component levels

• R800 PSY

     UP