PI57007: ConcurrentModificationException in com.ibm.ws.scaling.controller.topology.RepositoryMonitor$UpdateHandler

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
8.5.5.12: 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

• ConcurrentModificationException in
  com.ibm.ws.scaling.controller.topology.RepositoryMonitor$Upd
  ateHandler
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:  All users of IBM WebSphere Application      *
  *                  Server Liberty Profile- Virtual             *
  *                  Enterprise/IM Component                     *
  ****************************************************************
  * PROBLEM DESCRIPTION: A ConcurrentModificationException in    *
  *                      RepositoryMonitor$UpdateHandler occurs  *
  *                      in the scaling controller               *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  A ConcurrentModificationException in
  RepositoryMonitor$UpdateHandler occurs in the scaling
  controller.  An FFDC file similar to the one shown below is
  recorded.  This may cause incorrect scaling decisions to occur.
  
  ------Start of DE processing------ = [1/26/16 15:40:12:080 EST]
  Exception = java.util.ConcurrentModificationException
  Source =
  com.ibm.ws.scaling.controller.topology.RepositoryMonitor$UpdateH
  andler
  probeid = 1025
  Stack Dump = java.util.ConcurrentModificationException
      at
  java.util.ArrayList$Itr.checkForComodification(ArrayList.java:91
  2)
      at java.util.ArrayList$Itr.next(ArrayList.java:862)
      at
  com.ibm.ws.imf.apc.IMMetricImpl.findBestLeafMetric(IMMetricImpl.
  java:356)
      at
  com.ibm.ws.imf.apc.IMMetricImpl.evaluate(IMMetricImpl.java:232)
      at
  com.ibm.ws.imf.apc.IMControllerImpl.updateContainerTree(IMContro
  llerImpl.java:458)
      at
  com.ibm.ws.scaling.controller.topology.RepositoryMonitor.modifyS
  erverState(RepositoryMonitor.java:850)
      at
  com.ibm.ws.scaling.controller.topology.RepositoryMonitor.access$
  600(RepositoryMonitor.java:72)
      at
  com.ibm.ws.scaling.controller.topology.RepositoryMonitor$UpdateH
  andler.run(RepositoryMonitor.java:992)
      at java.lang.Thread.run(Thread.java:785)
  

Problem conclusion

• This problem is caused by a lack of synchronization when
  multiple scaling members are starting in multiple clusters at
  the same time.  The synchronization has been corrected.
  
  The fix for this APAR is currently targeted for inclusion in fix
  pack 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
  

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

  LIBERTY PROFILE

• Fixed component ID

  5724J0814

Applicable component levels

• R855 PSY

     UP