IV25873: WMQ JMS TRANSACTION DOES NOT COMPLETE DUE TO CONNECTION BROKEN, BUT IS NOT ROLLED BACK IMMEDIATELY AND IS PROCESSED HOURS LATER

WebSphere MQ V7.5 Fix Pack 7.5.0.1
WebSphere MQ V7.0 Fix Pack 7.0.1.10
Fix Pack 7.1.0.3 for WebSphere MQ V7.1

APAR status

• Closed as program error.

Error description

• WebSphere MQ V7 classes for JMS application receives a return
  code 2009 'MQRC_CONNECTION_BROKEN' causing the JMS Connection
  and its associated Session to be closed.
  
  At the time the JMS Session was involved in a XA transaction.
  When the Transaction Manager (for example, WebSphere
  Application Server) attempts to call XA prepare on the
  Session, it received a XAER_NOTA XA return code (-4), due to
  the connection to the queue manager already being closed.
  
  Following this connection failure, the transaction became
  stranded, until the WebSphere MQ queue manager encountered a
  log-nearly-full condition.  At this point the transaction was
  rolled back.
  
  The message received under the transaction is locked until the
  transaction is rolled back.  This may occur many hours later
  when the WebSphere MQ transaction logs become full and
  incomplete transactions are rolled back to free space.
  
  The application server's SystemOut.log file records the
  message:
  
  javax.transaction.xa.XAException: The method 'xa_prepare' has
  failed with errorCode '-4'.
  
  When the transaction is eventually rolled back, WebSphere MQ
  queue manager logs record the message:
  
  AMQ7469:Transactions rolled back to release log space.
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  This issue affects users of the WebSphere MQ classes for JMS,
  who are making use of XA transactions.  This includes:
  
  - The WebSphere MQ V7 classes for JMS.
  - The WebSphere MQ V7 Resource Adapter.
  - The WebSphere Application Server V7 WebSphere MQ messaging
  provider.
  - The WebSphere Application Server V8 WebSphere MQ messaging
  provider.
  - The WebSphere Application Server V6.1 WebSphere MQ messaging
  provider who have configured the WebSphere variable
  MQ_INSTALL_ROOT to point to a WebSphere MQ V7 installation.
  
  Platforms affected:
  All Distributed (iSeries, all Unix and Windows) +Java +Java zOS
  ****************************************************************
  PROBLEM SUMMARY:
  When an XASession object is requested to 'prepare' by the
  transaction manager, the WebSphere MQ classes for JMS returned
  an inappropriate XA return code when the XASession was closed
  between the 'XA end' and 'XA prepare' calls, for example in the
  event where the TCP network connection was lost between the
  WebSphere MQ classes for JMS and the queue manager.
  
  This resulted in the transaction manager not communicating with
  queue manager to request that this transaction is cleaned up,
  leaving the transaction in an idle state until the transaction
  is completed (rolledback) when the queue manager transaction
  logs wrap.
  
  The consequence of this in the WebSphere Application Server
  environment where the message was being used to drive an MDB,
  is that the message was not consumed again from the queue until
  the transaction had been rolled back and the message became
  visible on the queue, which may be several hours after it was
  originally consumed.
  

Problem conclusion

• The code change associated with this APAR resolves the issue
  by the XASession throwing the more appropriate 'XAER_RMFAIL'
  return code on the prepare request, when the XASession has been
  prematurely closed.
  
  This results in the transaction manager recreating the XA
  resource and ensuring that the resource is retried to complete
  the transaction automatically on the queue manager.
  
  If the transaction manager being used is WebSphere Application
  Server v6.1, then the WebSphere Application Server APAR PM70624
  is also required to be installed on the application server in
  order for the WebSphere MQ classes for JMS code to function
  as described.  WebSphere Application Server v7 or above
  does not require any additional APARs other than this WebSphere
  MQ classes for JMS APAR.
  
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
                     v7.0
  Platform           Fix Pack 7.0.1.10
  --------           --------------------
  Windows            U200352
  AIX                U853055
  HP-UX (PA-RISC)    U853082
  HP-UX (Itanium)    U853087
  Solaris (SPARC)    U853083
  Solaris (x86-64)   U853089
  iSeries            7.0.1.10
  Linux (x86)        U853084
  Linux (x86-64)     U853088
  Linux (zSeries)    U853085
  Linux (Power)      U853086
  zOS                7.0.1.10
  
                     v7.1
  Platform           Fix Pack 7.1.0.3
  --------           --------------------
  Windows            7.1.0.3
  AIX                7.1.0.3
  HP-UX (Itanium)    7.1.0.3
  Solaris (SPARC)    7.1.0.3
  Solaris (x86-64)   7.1.0.3
  iSeries            7.1.0.3
  Linux (x86)        7.1.0.3
  Linux (x86-64)     7.1.0.3
  Linux (zSeries)    7.1.0.3
  Linux (Power)      7.1.0.3
  zOS                7.1.0.3
  
  Platform           v7.5
  --------           --------------------
  Multiplatforms     7.5.0.1
  
  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

  WMQ AIX V7

• Fixed component ID

  5724H7221

Applicable component levels

• R701 PSY

     UP