IC64514: MULTI-THREADED WMQ V7 ASYNCHRONOUS JMS MESSAGE CONSUMER HANGS WHEN ISSUING A COMMIT AND STOP ON THE SAME CONNECTION OBJECT

WebSphere MQ V7.0 Fix Pack 7.0.1.2
WebSphere MQ V7.0.1 for i5/OS Fix Pack 7.0.1.2

APAR status

• Closed as program error.

Error description

• A multi-threaded WebSphere MQ v7 asynchronous JMS Message
  consumer hangs when one thread receives a message and
  issues a commit on the session, and another thread issues
  a stop on the same connection object used by the first
  thread which is yet to commit the message.
  .
  Both these threads end up in a hung state. The following
  exception stack trace can be seen in the java cores
  indicating a hang when committing the session:
  .
  4XESTACKTRACE at com/ibm/msg/client/jms/internal/
  JmsSessionImpl.commit(Bytecode PC:20)
  4XESTACKTRACE at com/ibm/mq/jms/MQSession.commit
  (Bytecode PC:20)
  4XESTACKTRACE at com/ibm/micro/internal/bridge/
  connection/jms/common/JMSBridgeConnection.
  commitMsgFromListener(Bytecode PC:19)
  4XESTACKTRACE at com/ibm/micro/internal/bridge/Pipe.
  putIncomingPointToPointMessage
  (Bytecode PC:378)
  4XESTACKTRACE at com/ibm/micro/internal/bridge/Pipe.
  putIncomingMessage(Bytecode PC:40)
  4XESTACKTRACE at com/ibm/micro/internal/bridge/Pipe.
  handleInboundBridgeMessage(BytecodePC
  :409(Compiled Code))
  4XESTACKTRACE at com/ibm/micro/internal/bridge
  /connection/jms/common/JMSBridgeConnection.
  incomingMessageArrived(Bytecode PC:50)
  4XESTACKTRACE at com/ibm/micro/internal/bridge
  /connection/jms/common/
  JMSBridgeMessageListener$MQJMSListener
  .onMessage(Bytecode PC:19)
  4XESTACKTRACE at com/ibm/mq/jms/MQMessageConsumer$
  FacadeMessageListener.onMessage
  (Bytecode PC:159)
  4XESTACKTRACE at com/ibm/msg/client/jms/internal/
  JmsMessageConsumerImpl$JmsProviderMessage
  Listener.onMessage(Bytecode PC:205)
  4XESTACKTRACE at com/ibm/msg/client/wmq/v6/jms/internal/
  MQMessageConsumer.receiveAsync(Bytecode
  PC:392(Compiled Code))
  4XESTACKTRACE at com/ibm/msg/client/wmq/v6/jms/internal/
  SessionAsyncHelper.run(Bytecode PC:655)
  .
  .
  The thread hung while closing the connection is:
  .
  4XESTACKTRACE at java/lang/Object.wait(Native Method)
  4XESTACKTRACE at java/lang/Object.wait(Bytecode PC:3
  (Compiled Code))
  4XESTACKTRACE at com/ibm/msg/client/wmq/v6/jms/internal/
  SessionAsyncHelper.waitForPaused
  (Bytecode PC:63)
  4XESTACKTRACE at com/ibm/msg/client/wmq/v6/jms/internal/
  MQSession.stop(Bytecode PC:91)
  4XESTACKTRACE at com/ibm/msg/client/jms/internal/
  JmsSessionImpl.stop(Bytecode PC:256)
  4XESTACKTRACE at com/ibm/msg/client/jms/internal/
  JmsSessionImpl.stop(Bytecode PC:16)
  4XESTACKTRACE at com/ibm/msg/client/jms/internal/
  JmsConnectionImpl.stop(Bytecode PC:80)
  4XESTACKTRACE at com/ibm/mq/jms/MQConnection.stop
  (Bytecode PC:20)
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  This issue affects users of the WebSphere MQ classes for Java
  Message Service (JMS) whose applications access the JMS session
  object from within an onMessage method.
  
  Platforms affected:
  All Distributed (iSeries, all Unix and Windows) +Java
  ****************************************************************
  PROBLEM SUMMARY:
  The hang condition occurs due to a dead-lock between the thread
  issuing a JMS connection stop, and the thread issuing the commit
  whilst within the onMessage method.
  

Problem conclusion

• To prevent the hang condition occurring, the WebSphere MQ
  classes for JMS have been updated to not obtain the lock
  required for stopping until the onMessage has completed.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
                     v7.0
  Platform           Fix Pack 7.0.1.2
  --------           --------------------
  Windows            U200316
  AIX                U829807
  HP-UX (PA-RISC)    U829678
  HP-UX (Itanium)    U829681
  Solaris (SPARC)    U829806
  Solaris (x86-64)   U829680
  iSeries            tbc_p700_0_1_2
  Linux (x86)        U829677
  Linux (x86-64)     U829676
  Linux (zSeries)    U829682
  Linux (Power)      U829679
  
  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 WINDOWS V7

• Fixed component ID

  5724H7220

Applicable component levels

• R701 PSY

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