PI53170: CLASSLOADER LEAK CAUSES OUTOFMEMORYERROR WHEN APPLICATIONS REPEATEDLY RESTARTED WITHOUT RESTARTING APPLICATION SERVER

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
8.5.5.12: WebSphere Application Server V8.5.5 Fix Pack 12
8.5.5.13: WebSphere Application Server V8.5.5 Fix Pack 13
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
8.5.5.21: WebSphere Application Server V8.5.5.21

APAR status

• Closed as program error.

Error description

• When an application is repeatedly stopped and started without
  restarting the application server, a classloader leak may occur
  and lead to a Java heap OutOfMemoryError.
  
  When the classloader leak occurs, the Javacores that are
  produced by the OutOfMemoryError will be very large with many
  sets of duplicate classes being loaded.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:  All users of IBM WebSphere Application      *
  *                  Server V8.5.5.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: In some instances, the session          *
  *                      invalidator may maintain a reference    *
  *                      to an application classloader on        *
  *                      application restart.                    *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  The Session Manager invalidation thread may maintain a
  reference to an existing application classloader when the
  application is restarted. These classloaders can build up in
  memory, contributing to an OutOfMemory error.
  

Problem conclusion

• Changes were made to the Session Invalidator thread to ensure
  more consistent cleanup of references to application
  classloaders.
  
  The fix for this APAR is currently targeted for inclusion in
  fix pack 8.5.5.10.  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

• R850 PSY

     UP