Fix (APAR):  PQ90851

Status:  Fix

Release:  5.1.0.6,5.1.0.5,5.1.0.4,5.1.0.3

Operating System:  AIX,HP-UX,Linux,Solaris,Windows

Supersedes Fixes:  

CMVC Defect:  PQ90851

Byte size of APAR:  4747

Date: 2008-07-01

Abstract:  For a multi-threaded access of a resource reference, a message is logged that 'Resource Reference' is not found, in spite of the fact it is defined.

Description/symptom of problem:  
PQ90851 resolves the following problem:

ERROR DESCRIPTION:                                              
Resource reference lookup is not thread safe.  During excessive 
load the Resource Reference is not found.                       

LOCAL FIX:                                                      
No local fix.                                                   

PROBLEM SUMMARY

USERS AFFECTED:
Enterprise Java Bean (EJB) developers who
code their application to use 'Resource
Reference'.

PROBLEM DESCRIPTION:
For a multi-threaded access of a
resource reference, a message is
logged that 'Resource Reference' is
not found, in spite of the fact it is
defined.

RECOMMENDATION:
None

This APAR fixes a scenerio where multiple threads are
accessing the same bean and resource.  Multi-threaded lookup
of a resource reference fails and a  message is logged to
indicate so. The problem occurs only during multi-threaded
access.

PROBLEM CONCLUSION:                                             
Code modified to allow for checking and synchronizing access    
to the resource reference object.                               


Directions to apply fix:  
NOTE: Choose the:
1) Release the fix applies to
2) The Editions that apply
3) Delete the Editions & Methods that do not apply and this Note

Fix applies to Editions:
Release:
5.0  5.1
___  _x__ Application Server (Express or BASE)
___   x   Enterprise Edition (DD)
___  ___ Network Deployment (ND)
___  ___ Edge Components
___  ___ Developers Edition
___  ___ Tools
     ___ WebSphere Business Integration Server Foundation (WBISF)

Install Fix to:
Method:
_x_ Application Server Nodes
_x_ Deployment Manager Nodes
__ Both

NOTE:
The user must:
* Have Administrative rights in Windows, or be the Actual Root User in a UNIX environments.
* Be logged in with the same authority level when unpacking a fix, fix pack or refresh pack.

The Update Installer can be downloaded from the following link:
http://www.ibm.com/support/docview.wss?rs=180&uid=swg21205991

The Update Installer for V5.0 does not have a maintenance directory.
It uses fixpacks and fixes as the location of the unpacked files.

1) Copy PQ90851.jar file directly to the maintenance directory

2) Shutdown WebSphere
Manually execute setupCmdLine.bat in Windows or . ./setupCmdLine.sh in Unix from the WebSphere instance that maintenance is being applied to.

3) Launch Update Installer

4) Enter the installation location of the WebSphere product you want to update.

5) Select the "Install maintenance package" operation.

6) Enter the file name of the maintenance package to install (PQ90851.jar file which was copied in the maintenance directory).
The V5.0 and V5.1 fix packs and fixes are unpacked as .jar files and should be unpacked into fixpacks or fixes directory.

7) Install the maintenance package.

8) Restart WebSphere

Directions to remove fix:  
NOTE:
* The user must have Administrative rights in Windows, or be the Actual Root User in a UNIX environments.
* FIXES MUST BE REMOVED IN THE ORDER 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, fix2 removed, and fix3 re-applied.

1) Shutdown WebSphere
Manually execute setupCmdLine.bat in Windows or . ./setupCmdLine.sh in Unix from the WebSphere instance that uninstall is being run against.

2) Start Update Installer

3) Enter the installation location of the WebSphere product you want to remove the fix.

4) Select  "Uninstall maintenance package" operation.

5) Enter the file name of the maintenance package to uninstall (PQ90851.jar).

6) UnInstall maintenance package.

7) Restart WebSphere

Directions to re-apply fix:  
1) Shutdown WebSphere.

2) Follow the Fix instructions to apply the fix.

3) Restart WebSphere.



Additional Information: