IT06013: WMQ JAVA/JMS 7.5 APPLICATION HUNG WHEN CREATING A CONNECTION TO QUEUE MANAGER AND USING A DAEMON THREADGROUP

Fix Pack 8.0.0.2 for WebSphere MQ V8.0

APAR status

• Closed as program error.

Error description

• A WebSphere MQ classes for Java/JMS 7.5 application created a
  connection to a queue manager, and the application threw an
  exception of the form:
  
  Exception in thread "JMSCCThreadPoolMaster"
  java.lang.IllegalThreadStateException
    at java.lang.ThreadGroup.checkNewThread(ThreadGroup.java:147)
    at java.lang.Thread.initialize(Thread.java:334)
    at java.lang.Thread.(Thread.java:267)
    at java.lang.Thread.(Thread.java:356)
    at
  com.ibm.msg.client.commonservices.j2se.workqueue.WorkQueueManage
  rImplementationThreadPoolWorker.(WorkQueueManagerImplementation.
  java:950)
   at
  com.ibm.msg.client.commonservices.j2se.workqueue.WorkQueueManage
  rImplementation.createNewThread(WorkQueueManagerImplementation.j
  ava:496)
   at
  com.ibm.msg.client.commonservices.j2se.workqueue.WorkQueueManage
  rImplementation.getWorkerThread(WorkQueueManagerImplementation.j
  ava:433)
   at
  com.ibm.msg.client.commonservices.j2se.workqueue.WorkQueueManage
  rImplementation.access$100(WorkQueueManagerImplementation.java:4
  6)
   at
  com.ibm.msg.client.commonservices.j2se.workqueue.WorkQueueManage
  rImplementation$WorkQueueManagerThread.run(WorkQueueManagerImple
  mentation.java:848)
  
  After this, the application thread which was requesting the
  connection hung.
  
  Additional Symptom(s) Search Keyword(s):
  

Local fix

• Ensure that the ThreadGroup which the application's queue
  manager connection requesting thread is not a part of a
  ThreadGroup which is of the daemon type.
  

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Users of the WebSphere MQ classes for Java and WebSphere MQ
  classes for JMS, which are using an application thread which is
  part of a ThreadGroup which is of the daemon type.
  
  This does NOT affect users of the WebSphere Application Server,
  or other application servers where threads are provided to the
  WebSphere MQ classes for Java/JMS by the JEE environment.
  
  
  Platforms affected:
  AIX, MultiPlatform, HP-UX Itanium, HP-UX PA-RISC, IBM iSeries,
  Linux on Power, Linux on S390, Linux on x86, Linux on x86-64,
  Linux on zSeries, Solaris SPARC, Solaris x86-64, Windows, z/OS
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  When using the WebSphere MQ classes for Java/JMS in a
  stand-alone Java environment, threads created by the WebSphere
  MQ classes for Java/JMS for its internal function will inherit
  properties from the application thread.
  
  One of these inherited properties is the daemon state of the
  "java.lang.ThreadGroup" which the thread belongs to. The daemon
  state of the ThreadGroup determines if the ThreadGroup should be
  destroyed once the last thread in the group ends or is
  destroyed. Once this happens - no further threads can be added
  to the ThreadGroup.
  
  
  If an application closes all connections to the queue manager,
  then all the threads will be removed from the ThreadGroup. If it
  has the daemon status, then the ThreadGroup will be marked as
  destroyed. If the application should then attempt to open a new
  connection to the queue manager, an exception will be thrown and
  the thread requesting the connection will hang. The exception is
  of the form (stack taken from the 7.5.0.3 version of the
  WebSphere MQ classes for Java/JMS):
  
  Exception in thread "JMSCCThreadPoolMaster"
  java.lang.IllegalThreadStateException
          at
  java.lang.ThreadGroup.checkNewThread(ThreadGroup.java:147)
          at java.lang.Thread.initialize(Thread.java:334)
          at java.lang.Thread.(Thread.java:267)
          at java.lang.Thread.(Thread.java:356)
          at
  com.ibm.msg.client.commonservices.j2se.workqueue.WorkQueueManage
  rImplementation$ThreadPoolWorker.(WorkQueueManagerImplementation
  .java:950)
          at
  com.ibm.msg.client.commonservices.j2se.workqueue.WorkQueueManage
  rImplementation.createNewThread(WorkQueueManagerImplementation.j
  ava:496)
          at
  com.ibm.msg.client.commonservices.j2se.workqueue.WorkQueueManage
  rImplementation.getWorkerThread(WorkQueueManagerImplementation.j
  ava:433)
          at
  com.ibm.msg.client.commonservices.j2se.workqueue.WorkQueueManage
  rImplementation.access$100(WorkQueueManagerImplementation.java:4
  6)
          at
  com.ibm.msg.client.commonservices.j2se.workqueue.WorkQueueManage
  rImplementation$WorkQueueManagerThread.run(WorkQueueManagerImple
  mentation.java:848)
  

Problem conclusion

• The WebSphere MQ classes for Java/JMS have been updated to
  ensure that regardless of the daemon status of the ThreadGroup
  which the application's thread belongs to - the ThreadGroup
  created by the WebSphere MQ classes for Java/JMS is not of the
  daemon type.
  
  This means that all the threads from this ThreadGroup can be
  created and stopped/destroyed, and new threads can be added to
  the ThreadGroup, resolving the issue.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v7.5       7.5.0.6
  v8.0       8.0.0.2
  
  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 BASE MULTIP

• Fixed component ID

  5724H7241

Applicable component levels

• R750 PSY

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