IT25282: A IBM MQ classes for JMS asynchronous MessageConsumer does not drive a MessageListener even though messages are present

APAR status

• Closed as program error.

Error description

• A IBM MQ classes for JMS application is running, using an
  asynchronous MessageConsumer, one which was created using
  the method:
  
   javax.jms.MessageConsumer.setMessageListener(
                    javax.jms.MessageListener)
  
  The associated MQ classes for JMS Connection object is running
  in "migration mode".
  
  This could, for example, be because either the application:
  
  (a) Is connecting to an MQ channel where SHARECNV(0) has been
  defined.
  
  or
  
  (b) has configured the associated MQConnectionFactory has been
  configured with the property:
  
          ProviderVersion="6"
  
    through the use of the method call:
  
  
  com.ibm.mq.jms.MQConnectionFactory.setProviderVersion("6")
  
  
  Even though there are messages present and available to be
  consumed on the queue, the asynchronous MessageConsumer is not
  consuming them and driving the MessageListener.
  
  
  Prior to the problem occurring, the application had been
  calling:
  
   javax.jms.MessageConsumer.close();
  
  on a MessageConsumer which had been created from the same JMS
  "javax.jms.Session" object instance as the MessageConsumer which
  subsequently was not returning messages.
  

Local fix

• Either:
  
  a) use the MQ classes for JMS in the normal or
  normal-with-restrictions mode of operation,
  
  or
  
  b) close and recreate the JMS resources used by the application.
  

Problem summary

• ****************************************************************
  USERS AFFECTED:
  This issue affects applications using the MQ classes for JMS
  that are operating in migration mode and have configured an
  asynchronous MessageListener on a MessageConsumers created from
  the same JMS Session as other MessageConsumers.
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  When the MQ classes for JMS are operating in migration mode, and
  the application has configured message listeners to consume
  messages asynchronously, an internal client thread called the
  "SessionAsyncHelper" thread performs polling MQGET calls on MQ
  destinations to consume messages that can be delivered to the
  configured message listeners.
  
  If the application called the method:
  
    javax.jms.MessageConsumer.close()
  
  then a timing window existed whereby the SessionAsyncHelper
  thread would end because the MQ destination it was about to
  issue an MQGET API call on was closed and dereferenced.  After
  the SessionAsyncHelper thread stopped, no more messages would be
  delivered to message listeners, even those associated with
  non-closed message listeners.
  
  This problem was introduced by APAR IT24240:
  
  http://www.ibm.com/support/docview.wss?uid=swg1IT24240
  
  which was first shipped within:
  
   IBM MQ v9.0.0.4
  
  The issue was fixed prior to the shipping of APAR IT24240 in IBM
  MQ 8.0 - so this APAR does not apply to IBM MQ v8.0.
  

Problem conclusion

• The IBM MQ classes for JMS have been updated to protect against
  the SessionAsyncHelper thread ending when a MessageConsumer is
  being closed.
  
  If the SessionAsyncHelper thread detects a dereferenced MQ
  destination and the MessageConsumer has been closed, it removes
  the destination from its internal list of destinations to poll
  for messages.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v9.0 LTS   9.0.0.5
  
  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 M/P

• Fixed component ID

  5724H7261

Applicable component levels