Fix (APAR):  JR33299

Status:  Fix

Release:  6.2.0.1

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

Supersedes Fixes:  

CMVC Defect:  xxxxxx

Byte size of APAR:  51650

Date: 2009-06-23

Abstract:  High CPU usage in java.util.HashMap.get() when new a BusObj.

Description/symptom of problem:  
JR33299 resolves the following problem:

ERROR DESCRIPTION:                                              
High CPU usage is observed when customer is migrating ICS to WPS
6201 BusObj API. The threaddump shows many threads are waiting  
at:                                                             
                                                                
at java.util.HashMap.get(HashMap.java:346)                      
at CxCommon.BusinessObject.<init>(BusinessObject.java:277)      
at Collaboration.BusObj.<init>(BusObj.java:94)                  
                                                                
and caused performance degradation.                             
                                                                
Migration fix will bypass this Java issue by using              
ConcurrentHashMap                                               

LOCAL FIX:                                                      
It maybe possible to avoid this situation by reducing the       
concurrency of the system                                       

PROBLEM SUMMARY

USERS AFFECTED:
WebSphere Process Server v6.2.0.x users
who migrated a WebSphere InterChange
Server repository.

PROBLEM DESCRIPTION:
High CPU usage in
java.util.HashMap.get() when new a
BusObj.

RECOMMENDATION:
None

The java.util.HashMap is not thread safe and will cause high
CPU usage when HashMap is used in a concurrent setting with
insufficient synchronization.

PROBLEM CONCLUSION:                                             
Applying this interim fix will solve this problem.              
The fix for this APAR is targeted for                           
inclusion in a future v6.2.0.x fixpack.                         


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: