PM67377: EXCESSIVE WARNING MESSAGES CAN APPEAR IN THE LOG DURING SESSION INVALIDATION WHEN A SERVER IS UNDER LOAD.

8.5.0.1: WebSphere Application Server V8.5 Fix Pack 1
8.5.0.2: WebSphere Application Server V8.5 Fix Pack 2
8.0.0.6: WebSphere Application Server V8.0 Fix Pack 6
8.0.0.7: WebSphere Application Server V8.0 Fix Pack 7
8.0.0.8: WebSphere Application Server V8.0 Fix Pack 8
8.0.0.9: WebSphere Application Server V8.0 Fix Pack 9
8.0.0.10: WebSphere Application Server V8.0 Fix Pack 10
8.0.0.11: WebSphere Application Server V8.0 Fix Pack 11
8.0.0.12: WebSphere Application Server V8.0 Fix Pack 12
8.0.0.13: WebSphere Application Server V8.0 Fix Pack 13
8.0.0.14: WebSphere Application Server V8.0 Fix Pack 14
8.0.0.15: WebSphere Application Server V8.0 Fix Pack 15

APAR status

• Closed as program error.

Error description

• Even if the server is processing correctly, the following
  warning may appear in the logs with the
  WsSessionInvalidator.alarm triggering the message.
  
  [5/16/12
  13:54:58:320
  EDT]
  00000073
  AlarmThreadMo
  W
  UTLS0008W: The return of alarm thread "Non-deferrable Alarm :
  0" (00000005) to the alarm thread pool has been delayed for
  31194 milliseconds. This may be preventing normal alarm
  function within the application server. The alarm listener
  stack trace is as follows:
  ...
   at
  com.ibm.ws.session.WsSessionInvalidator.alarm(WsSessionInvalidat
  or.java:64)
   at com.ibm.ejs.util.am._Alarm.run(_Alarm.java:133)
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:  IBM WebSphere Application Server Version    *
  *                  8.0 and 8.5 users.                          *
  ****************************************************************
  * PROBLEM DESCRIPTION: When a system is under heavy load,      *
  *                      some warning messages could appear in   *
  *                      the logs about session invalidation     *
  *                      taking too long.                        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  When a system is under heavy load, session invalidation
  occurs, and the invalid sessions have listeners associated
  with them; session invalidation might take longer than the
  expected amount of time causing a warning message to be
  printed in the trace.
  

Problem conclusion

• The Session Manager code has been updated to use its own
  threadpool to manage invalidation.  This can be set by the
  Session manager custom property,
  UseSeparateSessionInvalidatorThreadPool = true.
  The SessionInvalidatorThreadPoolSize can also be used to
  configure the size of this threadpool.  The default value is
  50.
  
  The fix for this APAR is currently targeted for inclusion in
  fix pack 8.0.0.6 and fix pack 8.5.0.2.  Please refer to the
  Recommended Updates page for delivery information:
  http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
  

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

  WEBS APP SERV N

• Fixed component ID

  5724H8800

Applicable component levels

• R700 PSY

     UP

• R850 PSY

     UP