PH50062: MDB CLASS JAVA HEAP LEAK ON APPLICATION START/STOP

APAR status

• Closed as program error.

Error description

• WebSphere Platform 9.0.5.11
  
  Host Operating System is Windows 10, version 10.0
  Java version = 1.8.0_321, Java Runtime Version = 8.0.7.5 -
  pwa6480sr7fp5-20220208_01(SR7 FP5), Java Compiler = j9jit29,
  Java VM name = IBM J9 VM
  There is a reference from the WAS MDB code to the application's
  MDB class, through a pool that does not appear to be cleaned on
  application stop.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:  All users of IBM WebSphere Application      *
  *                  Server                                      *
  *                  with message-driven bean applications       *
  ****************************************************************
  * PROBLEM DESCRIPTION: Message-driven bean (MDB) classes       *
  *                      leaked                                  *
  *                      on application stop.                    *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  When a message-driven bean (MDB) application is stopped, the MDB
  classes and the application ClassLoader are leaked. No errors
  occur, however a heap analysis will show the following reference
  chain:
  '- enterpriseBeanClass
  com.ibm.ejs.container.MessageEndpointFactoryImpl @ 0x8d630f50
  '- ivMessageEnpointHandlerFactory
  com.ibm.ws.ejbcontainer.mdb.MessageEndpointHandlerPool @
  0x8d6307c8
  '- discardStrategy
  com.ibm.ws.ejbcontainer.util.PoolImplThreadSafe @ 0x8d6301e0
  '- [3] java.lang.Object[10] @ 0x8677de20
  '- elementData java.util.ArrayList @ 0x817b8f10
  '- pools
  com.ibm.ws.ejbcontainer.util.PoolManagerImpl @ 0x817b8ee8
  '- poolManager
  com.ibm.ejs.container.EJSContainer @ 0x80f024e0
  

Problem conclusion

• The enterprise beans container MessageEndpointFactory
  implementation contains a pool of invocation handler objects
  that are not cleared on application stop. Since the invocation
  handler objects reference the application message-driven bean
  classes, this results in a leak.
  
  The enterprise beans container implementation has been updated
  to clear the pool of invocation handlers on application stop,
  eliminating the leak.
  
  The fix for this APAR is targeted for inclusion in fix pack
  8.5.5.23, 9.0.5.15, and 22.0.0.12. For more information, see
  'Recommended Updates for WebSphere Application Server':
  https://www.ibm.com/support/pages/node/715553
  

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 APP S

• Fixed component ID

  5724J0800

Applicable component levels