PI44496: USERS SEE MANY THREADS GENERICALLY NAMED THREAD-XX, LIKE "THREAD-23"

8.0.0.12: WebSphere Application Server V8.0 Fix Pack 12
8.5.5.9: WebSphere Application Server V8.5.5 Fix Pack 9
8.5.5.10: WebSphere Application Server V8.5.5 Fix Pack 10
8.5.5.11: WebSphere Application Server V8.5.5 Fix Pack 11
8.0.0.13: WebSphere Application Server V8.0 Fix Pack 13
8.5.5.12: WebSphere Application Server V8.5.5 Fix Pack 12
8.0.0.14: WebSphere Application Server V8.0 Fix Pack 14
8.5.5.13: WebSphere Application Server V8.5.5 Fix Pack 13
8.0.0.15: WebSphere Application Server V8.0 Fix Pack 15
8.5.5.14: WebSphere Application Server V8.5.5 Fix Pack 14
8.5.5.15: WebSphere Application Server V8.5.5 Fix Pack 15
8.5.5.17: WebSphere Application Server V8.5.5 Fix Pack 17
8.5.5.20: WebSphere Application Server V8.5.5.20
8.5.5.18: WebSphere Application Server V8.5.5 Fix Pack 18
8.5.5.19: WebSphere Application Server V8.5.5 Fix Pack 19
8.5.5.16: WebSphere Application Server V8.5.5 Fix Pack 16

APAR status

• Closed as program error.

Error description

• Customer noticed many (around 30) threads in his javacores with
  generically named threads and very similar java stacks:
  
  3XMTHREADINFO      "Thread-80" J9VMThread:0x0000000026D8FB00,
  j9thread_t:0x0000004808BA58F0,
  java/lang/Thread:0x0000000095096708,
  state:P, prio=5
  3XMJAVALTHREAD            (java/lang/Thread getId:0xCB,
  isDaemon:true)
  3XMTHREADINFO1            (native thread ID:0x242C8600, native
  priority:
  0x5, native policy:UNKNOWN, vmstate:P, vm thread
  flags:0x000a0001)
  3XMCPUTIME               CPU usage total: 0.101000000 secs
  3XMTHREADBLOCK     Parked on:
  java/util/concurrent/locks/AbstractQueuedSynchronizer$ConditionO
  bject@0x
  0000000083253850 Owned by: <unknown>
  3XMHEAPALLOC             Heap bytes allocated since last GC
  cycle=0
  (0x0)
  3XMTHREADINFO3           Java callstack:
  4XESTACKTRACE                at sun/misc/Unsafe.park(Native
  Method)
  4XESTACKTRACE                at
  java/util/concurrent/locks/LockSupport.
  parkNanos(LockSupport.java:222(Compiled Code))
  4XESTACKTRACE                at
  java/util/concurrent/locks/AbstractQueuedSynchronizer$ConditionO
  bject.
  awaitNanos(AbstractQueuedSynchronizer.java:2036(Compiled Code))
  4XESTACKTRACE                at
  java/util/concurrent/DelayQueue.take
  (DelayQueue.java:175(Compiled Code))
  4XESTACKTRACE                at
  java/util/concurrent/ScheduledThreadPoolExecutor$DelayedWorkQueu
  e.take
  (ScheduledThreadPoolExecutor.java:620(Compiled Code))
  4XESTACKTRACE                at
  java/util/concurrent/ScheduledThreadPoolExecutor$DelayedWorkQueu
  e.take
  (ScheduledThreadPoolExecutor.java:613(Compiled Code))
  4XESTACKTRACE                at
  java/util/concurrent/ThreadPoolExecutor.
  getTask(ThreadPoolExecutor.java:959(Compiled Code))
  4XESTACKTRACE                at
  java/util/concurrent/ThreadPoolExecutor$Worker.run(ThreadPoolExe
  cutor.
  java:917)
  4XESTACKTRACE                at
  java/lang/Thread.run(Thread.java:784)
  3XMTHREADINFO3           No native callstack available on this
  platform
  
  Further analysis of dumps showed that the threads are part of a
  pool of threads of type
  java/util/concurrent/ThreadPoolExecutor$Worker
  
  and
  final java.util.concurrent.ThreadPoolExecutor this$0
  
  points to
   com/ibm/ws/session/WsSessionInvalidatorWithThreadPool$Scheduled
  Executor
  

Local fix

• N/A, the threads are valid WAS threads and are there by design
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:  All users of IBM WebSphere Application      *
  *                  Server                                      *
  *                  V8.0 and V8.5                               *
  ****************************************************************
  * PROBLEM DESCRIPTION: WAS Session Invalidator threads are     *
  *                      generically named Thread-XX             *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  Session Invalidator threads are currently given a generic thread
  name, which can cause difficulty in assessing resource
  allocation
  and debugging issues with hung threads.
  

Problem conclusion

• The name of these threads were renamed to
  'WsSessionInvalidatorThread'.
  
  APAR PI44496 is currently targeted for inclusion in Fix Packs
  8.0.0.12 and 8.5.5.9.
  
  Please refer to the Recommended Updates page for delivery
  information:
  http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
  
  In addition, please refer to URL:
  http://www.ibm.com/support/docview.wss?rs=404&uid=swg27006970
  for Fix Pack PTF information.
  

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

  WEBSPHERE FOR Z

• Fixed component ID

  5655I3500

Applicable component levels

• R850 PSY

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