IT32212: Topic handles are not closed when a Classes for Java MQQueueManager disconnects

APAR status

• Closed as program error.

Error description

• When a Classes for Java application using connection pooling
  creates a number of topic objects from a queue manager object,
  and then calls disconnect on that queue manager object, the
  handles for these topics are not closed as expected before the
  queue manager instance is added to the pool to await reuse. When
  this queue manager is taken from the pool when the application
  creates a new queue manager instance, that new queue manager
  will have a reduced number of object handles available as a
  result of those previous topic handles not being closed - this
  can result in a 2017 MQRC_HANDLE_NOT_AVAILABLE error when
  creating topic object from this new queue manager instance when
  the number of object handles in use reaches the queue manager's
  object handle limit MAXHANDS.
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  This affects users of the Classes for Java who are also making
  use of both connection pooling and publish/subscribe
  functionality.
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  When a Classes for Java application created a new MQQueueManager
  instance with connection pooling enabled, and then used this
  queue manager object to create some new topic objects, and then
  called disconnect() on that queue manager to close the related
  objects and return the queue manger instance to the connection
  pool for later use, the topic objects owned by that queue
  manager instance were not closed as expected - calling
  disconnect() on a MQQueueManager instance should close all
  objects that had been created by that queue manager instance.
  
  So when another MQQueueManager object was created by that same
  application, and that original queue manager instance was taken
  from the pool to be reused, that queue manager instance still
  had a number of open handles in use that had not been closed,
  from the original topics created. This meant that when this new
  queue manager instance was used to open queues, topic and other
  objects for use, there was a smaller number of available topic
  handles available for use.
  
  This process could then be repeated if disconnect() was then
  called on this queue manager object. Eventually, an attempt to
  open a queue or topic object from the queue manager instance
  could fail with MQRC_HANDLE_NOT_AVAILABLE, as the queue manager
  had not cleared any of the topic handles that had been in use.
  

Problem conclusion

• When a Classes for Java queue manager disconnects, all topics
  associated with that queue manager are closed and the handles
  are cleared, matching the behaviour for other types of object
  creates for a queue manager instance.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v9.1 LTS   9.1.0.7
  v9.2 LTS   9.2.0.2
  v9.x CD    9.2.1
  
  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

  5724H7271

Applicable component levels