JR52097: YOU RECEIVE A CONCURRENTMODIFICATIONEXCEPTION WHEN SERVICE RESULTS ARE CACHED

8.5.0.1-WS-BPM-IFJR52097
Version 8.5 Refresh Pack 6 for the IBM Business Process Manager products
Version 8.5.0 Fix Pack 2 for the IBM Business Process Manager products

APAR status

• Closed as program error.

Error description

• When many services run with service result caching enabled, a
  ConcurrentModificationException might occur in the system log
  file with the following message:
  
  CWLLG0594E: An exception occurred while initializing the
  runnable thread. Error:
  java.util.ConcurrentModificationException
  The exception stack trace looks similar to the following
  exception stack trace:
  
  java.util.ConcurrentModificationException
   at java.util.LinkedHashMap$AbstractMapIterator.
    checkConcurrentMod(LinkedHashMap.java:136)
   at java.util.LinkedHashMap$AbstractMapIterator.makeNext
    (LinkedHashMap.java:141)
   at java.util.LinkedHashMap$EntryIterator.next(LinkedHashMap.
    java:188)
   at java.util.LinkedHashMap$EntryIterator.next(LinkedHashMap.
    java:180)
   at com.ibm.bpm.server.service.cache.ServiceResultCache.
    removeExpiredResults(ServiceResultCache.java:176)
   at com.ibm.bpm.server.service.cache.ServiceResultCache.
    add(ServiceResultCache.java:87)
   at com.lombardisoftware.server.ejb.workflow.
    EJBWorkflowManagerBean.doResumeWorkflowEngine
    (EJBWorkflowManagerBean.java:1599)
   at com.lombardisoftware.server.ejb.workflow.
    EJBWorkflowManagerBean.runProcess(EJBWorkflowManagerBean.
    java:555)
   at com.lombardisoftware.server.ejb.workflow.
    EJSRemoteStatefulEJBWorkflowManager_82478d70.
    runProcess(Unknown Source)
   at com.lombardisoftware.server.ejb.workflow.
    _EJBWorkflowManagerInterface_Stub.runProcess
    (_EJBWorkflowManagerInterface_Stub.java:772)
   at com.ibm.bpm.rest.impl.service.ServiceRunner$Service.
    runService(ServiceRunner.java:704)
   at com.ibm.bpm.rest.impl.service.StartActionHandler.
    handleAction(StartActionHandler.java:219)
   at com.ibm.bpm.rest.impl.service.ServiceResource.
    postServiceActions(ServiceResource.java:409)
  

Local fix

Problem summary

• An iterator removes expired entries from the LinkedHashMap,
  which is used for the service result cache. You see a
  ConcurrentModificationException when the next action on the
  iterator is done because entries are removed from the map using
  the remove method of the map instead of using the remove method
  of the iterator. The documentation of LinkedHasMap describes
  that when using iterators the map needs to be modified using the
  iterator methods.
  

Problem conclusion

• A fix is available for IBM BPM V8.5.0.1 that removes the expired
  entries correctly from the service result cache.
  
  On Fix Central (http://www.ibm.com/support/fixcentral), search
  for JR52097:
  
  1. Select IBM Business Process Manager with your edition from
    the product selector, the installed version to the fix pack
    level, and your platform, and then click Continue.
  
  2. Select APAR or SPR, enter JR52097, and click Continue.
  
  When you download fix packages, ensure that you also download
  the readme file for each fix. Review each readme file for
  additional installation instructions and information about the
  fix.
  

Temporary fix

• Not applicable
  

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

  BPM STANDARD

• Fixed component ID

  5725C9500

Applicable component levels

• R850 PSY

     UP