IT28817: Performance degradation when using JMS MessageListeners toconsume non-persistent messages outside of a transaction

APAR status

• Closed as program error.

Error description

• An IBM MQ classes for JMS application:
  
  - Creates a MessageListener from a non-transacted JMS Session or
  Context.
  - Then uses the MessageListener to consume non-persistent
  messages.
  
  When the application is run using the IBM MQ V9.1.0.0 classes
  for JMS, the time taken for the MessageListener to process
  messages is slower than when using the MQ v8.0.0.5.
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  This issue affects users of:
  
  - The IBM MQ V8.0.0.6 (or later) classes for JMS.
  - The IBM MQ V9.0.0.1 (or later) classes for JMS.
  - The IBM MQ V9.1 classes for JMS.
  
  who have applications that:
  
  - Create a MessageListener from a non-transacted JMS Session or
  Context.
  - Use that MessageListener to consume non-persistent messages.
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  APAR IV78400 made some changes to the IBM MQ classes for JMS to
  resolve issues that would occur if an application processed
  messages where the MQMD and the RFH2 headers for the messages
  had conflicting values for the message persistence property.
  
  As a result of these changes, the IBM MQ classes for JMS would
  incorrectly assume that all non-persistent messages that were
  delivered to an asynchronous MessageListener were processed
  within a transaction.  This caused the IBM MQ classes for JMS to
  always flow an MQCMIT API call to the queue manager after a
  MessageListener had processed a message, regardless of whether
  the message was processed within a transaction or not.
  

Problem conclusion

• To resolve this issue, the IBM MQ classes for JMS have been
  updated to only flow an MQCMIT call to the queue manager if a
  MessageListener successfully processes a message within a
  transaction.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v8.0       8.0.0.13
  v9.0 LTS   9.0.0.8
  v9.1 LTS   9.1.0.4
  
  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

  IBM MQ BASE MP

• Fixed component ID

  5724H7271

Applicable component levels