Fix (APAR):  JR28127

Status:  Fix

Release:  6.0.2.3,6.0.2.2

Operating System:  AIX,HP-UX,i5/OS,Linux,Solaris,Windows

Supersedes Fixes:  

CMVC Defect:  JR28127

Byte size of APAR:  7997

Date: 2008-01-14

Abstract:  ConcurrentModificationException is thrown under stress testing situations.

Description/symptom of problem:  
JR28127 resolves the following problem:

ERROR DESCRIPTION:                                              
The MapMapList.iterate() method from WPS code creates some new  
HashMap which is not threadsafe. This results in a              
ConcurrentModificationException as below. This error is caused  
due to concurrent calls to this method.                         
                                                                
[12/3/07 12:05:24:185 CET] 00000098 ExceptionUtil E   CNTR0020E:
EJB                                                             
threw an unexpected (non-declared) exception during invocation  
of method                                                       
"transactionNotSupportedActivitySessionNotSupported" on bean    
"BeanId(nav-cons-pen-psak-navorgenhetApp#nav-cons-pen-psak-navor
genhetEJ                                                        
B.jar#Module, null)". Exception data: An error occurred while   
parsing                                                         
native data: The error message is:                              
java.util.ConcurrentModificationException: concurrent access to 
HashMap                                                         
attempted by Thread[WebContainer : 6,5,main].                   
Caused By: java.util.ConcurrentModificationException: concurrent
access                                                          
to HashMap attempted by Thread[WebContainer : 6,5,main]         
 at                                                             
com.ibm.wsspi.sca.webservice.data.WebServiceNativeDataHolder.get
Body(Web                                                        
ServiceNativeDataHolder.java:147)                               
 at                                                             
com.ibm.ws.sca.internal.message.impl.ManagedMessageImpl.getBody(
ManagedM                                                        
essageImpl.java:850)                                            
 at                                                             
com.ibm.ws.sca.internal.java.handler.JavaImplementationHandler.p
rocessMe                                                        
ssage(JavaImplementationHandler.java:291)                       
 at                                                             
com.ibm.ws.sca.internal.message.impl.MessageDispatcherImpl.proce
ssMessag                                                        
eWithPCI(MessageDispatcherImpl.java:700)                        
 at                                                             
com.ibm.ws.sca.internal.message.impl.MessageDispatcherImpl.proce
ssMessag                                                        
e(MessageDispatcherImpl.java:1148)                              
 at                                                             

LOCAL FIX:                                                      
NA                                                              

PROBLEM SUMMARY

USERS AFFECTED:
WebSphere Process Server users at 6.0.2.2
or later.

PROBLEM DESCRIPTION:
ConcurrentModificationException is
thrown under stress testing situations.

RECOMMENDATION:
None

MapMapList.interate() method is not thread safe, so under
stress test, ConcurrentModificationException is thrown. The
exception is:
java.util.ConcurrentModificationException: concurrent access
to HashMap attempted by Thread[WebContainer: 6,5,main]

PROBLEM CONCLUSION:                                             
Applying this interim fix will resolve the problem.             


Directions to apply fix:  
Download and follow Update Installer installation instructions.  The Update Installer can be downloaded from the following link:
http://www.ibm.com/support/docview.wss?rs=180&uid=swg21205991

1) Copy the pak file to the directory maintenance in the UpdateInstaller directory

2) Shutdown WebSphere Process Server. It is important that you perform a controlled and complete shutdown of the server to ensure that all transactions have completed, before installing the fix.

3) Run the UpdateInstaller and follow the prompts.

4) Restart WebSphere Process Server.

Directions to remove fix:  
NOTE:  FIXES MUST BE REMOVED IN THE REVERSE ORDER IN WHICH THEY WERE APPLIED.  DO NOT REMOVE A FIX UNLESS  ALL FIXES APPLIED AFTER IT HAVE FIRST BEEN REMOVED.  YOU MAY REAPPLY ANY REMOVED FIX.

Example:  If your system has fix1, fix2, and fix3 applied in that order and fix2 is to be removed, fix3 must be removed first, then fix2 may be removed

1) Shutdown WebSphere Process Server. It is important that you perform a controlled and complete shutdown of the server to ensure that all transactions have completed, before installing the fix.

2) Follow the Fix instructions that are packaged with the Fix Installer on how to uninstall and reinstall the Fix.

3) Restart WebSphere Process Server.

Directions to re-apply fix:  
1) Shutdown WebSphere. It is important that you perform a controlled and complete shutdown of the server to ensure that all transactions have completed, before installing the fix.

2) Run the UpdateInstaller and follow the instructions. The Update Installer can be downloaded from the following link:
http://www.ibm.com/support/docview.wss?rs=180&uid=swg21205991

3) Restart WebSphere Process Server.

Additional Information: