PM30718: ConcurrentModificationException in parallel portlet rendering co de

APAR status

• Closed as program error.

Error description

• Currently the PPR code clones the request and spawns a thread
  for every portlet which participates in the PPR.
  This is executed in the mentioned order, i. e.
  clone request, spawn and start thread, clone request, spawn
  and start thread, clone request, etc.
  As a consequence the threads which already started working can
  modify request attributes. The cloning of the request
  attributes
  (which actually is a HashMap) iterates over the attributes and
  if a concurrent thread modifies these attributes the
  ConcurrentModificationException is thrown.
  
  [1/1/11 12:00:00:000 GMT] 00006592 Servlet       E
  com.ibm.wps.engine. Servlet handleException EJPEJ0070E: An
  exception occurred while processing the request.
  
  java.util.ConcurrentModificationException
  at java.util.HashMap$HashIterator.nextEntry(HashMap
  .java:841)
  at java.util.HashMap$EntryIterator.next(HashMap
  .java:883)
  at java.util.HashMap$EntryIterator.next(HashMap
  .java:881)
  at java.util.HashMap.putAllForCreate(HashMap.java:481)
  at java.util.HashMap.clone(HashMap.java:713)
  at com.ibm.ws.webcontainer.srt
  .SRTServletRequest$SRTServletRequestHelper
  .clone(SRTServletRequest.java:2619)
  at com.ibm.ws.webcontainer.srt.SRTServletRequest
  .clone(SRTServletRequest.java:1025)
  at com.ibm.wps.engine.PathHttpServletRequestWrapper
  .cloneDelegate(PathHttpServletRequestWrapper.java:73)
  at com.ibm.wps.engine.PathHttpServletRequestWrapper
  .<init>(PathHttpServletRequestWrapper.java:171)
  

Local fix

• n/a
  

Problem summary

• ConcurrentModificationException in parallel portlet rendering
  code.
  

Problem conclusion

• The order described in "Error Description" will be modified
  such that cloning of the request happens for every thread prior
  to starting the threads.
  
  Manual Steps:
     None
  
  Failing Module(s):
     Portlet Container
  
  Affected Users:
     All users
  
  Version Information:
      Portal Version(s): 6.1.0.2
       Pre-Requisite(s):    (or the respective cumulative fix)
        Co-Requisite(s): ---
  
  Platform Specific:
     This fix applies to all platforms.
  
  A fix is available from Fix Central:
  
  http://www.ibm.com/eserver/support/fixes/fixcentral/swgquickorde
  r?apar=PM30718&productid=WebSphere%20Portal&brandid=5
  
  You may need to type or paste the complete address into your Web
  browser.
  

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 PORTA

• Fixed component ID

  5724E7600

Applicable component levels

• R61B PSY

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