PH52313: MEMORY LEAK IN JAXRS VECTOR

APAR status

• Closed as program error.

Error description

• JAXRS leak vector
  Three of the four application class loaders present in the dump
  with visible GC roots were referenced in the contextClassLoader
  field of ThreadPoolExecutor threads:
  Class Name
                        | Shallow Heap | Retained Heap
  ---------------------------------------------------------------
  -------------------------------------------------------
  com.ibm.ws.classloader.CompoundClassLoader @ 0x8153ddb0
  app:demo-ear7                 |          160 |         7,752
  |- contextClassLoader java.lang.Thread @ 0x81540f08
  pool-4-thread-1 JNI Global, Thread|          120 |           736
  
  |- contextClassLoader java.lang.Thread @ 0x81540f80
  pool-4-thread-2 JNI Global, Thread|          120 |           736
  
  |- contextClassLoader java.lang.Thread @ 0x81540ff8
  pool-4-thread-3 JNI Global, Thread|          120 |           736
  
  '- contextClassLoader java.lang.Thread @ 0x81541070
  pool-4-thread-4 JNI Global, Thread|          120 |           736
  
  ---------------------------------------------------------------
  -------------------------------------------------------
  
  References from running threads prevent GC, so any thread
  created in an application context must be stopped when the
  application is stopped (or have its context class loader set to
  a non-application class loader) in order to avoid leaking the
  class loader.
  
  Most of these thread pools appear to be abandoned, but I was
  able to trace one back, through what I believe is the instance
  of the application that was still running. That pool appears to
  have been created not by the application, but by the WAS CDI
  component:
  
  Class Name
                  | Shallow Heap | Retained Heap
  ---------------------------------------------------------------
  -------------------------------------------------
  workers java.util.concurrent.ThreadPoolExecutor @ 0x8155b180
                  |           80 |           488
  '- executorService com.ibm.ws.cdi.impl.weld.ExecutorServicesImpl
  @ 0x84118358    |           16 |            16
  ---------------------------------------------------------------
  -------------------------------------------------
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:  All users of IBM WebSphere Application      *
  *                  Server                                      *
  *                  with applications that include an EJB jar   *
  *                  file.                                       *
  ****************************************************************
  * PROBLEM DESCRIPTION: JAXRS is not always cleaning            *
  *                      the routerEJBMetaDataCache when         *
  *                      applications are stopped, causing a     *
  *                      slow                                    *
  *                      memory leak.                            *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  When an application containing an EJB jar file is started, JAXRS
  processing will add entries to the routerEJBMetaDataCache.
  These
  entries are not always cleaned up and therefore when
  applications
  are started and stopped repeatedly, without a restart of the
  server, a memory leak can occur over time.
  

Problem conclusion

• This problem is now resolved by cleaning the
  routerEJBMetaDataCache when applications are stopped.
  
  The fix for this APAR is targeted for inclusion in fix pack
  9.0.5.16 and 8.5.5.24. 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

  WEBS APP SERV N

• Fixed component ID

  5724H8800

Applicable component levels