Fix (APAR):  PK38322

Status:  Fix

Release:  6.1.0.5,6.1.0.3,6.1.0.2,6.1.0.1

Operating System:  AIX,HP-UX,i5/OS,Linux,Linux pSeries,Linux Red Hat - pSeries,Linux zSeries,OS/390,OS/400,Solaris,Windows,z/OS

Supersedes Fixes:  

CMVC Defect:  417457

Byte size of APAR:  126742

Date: 2007-04-04

Abstract:  Workload Management (WLM) race condition when Deployment Manager (DM) goes up and down

Description/symptom of problem:  
PK38322 resolves the following problem:

ERROR DESCRIPTION:                                              
The problem happens when the UCF is informed of a change to     
the cluster data, via the HA Bulletin Board and a selection is  
being executed at the same time..  This causes the UCF's        
selection algorithm select method to use cluster data that has  
been re- initialized with new cluster data but before the       
cluster data has been processed by the selection feedback and   
routing rules.   This leads to incorrect selection results.     

LOCAL FIX:                                                      

PROBLEM SUMMARY

USERS AFFECTED:
IBM WebSphere Application Server version 6.1
users with clustering and SIP Proxy

PROBLEM DESCRIPTION:
Workload Management (WLM) race
condition when Deployment Manager (DM)
goes up and down

RECOMMENDATION:
None

A race condition was exposed in WLM involving the SIP Proxy
handling traffic at the same time that the Deployment Mgr (DM)
is taken up and down.  To handle traffic, the SIP Proxy
extracts soemthing called the logical server ID (LSID) out of
each message and queries WLM/UCF to identify which backend SIP
Container owns that LSID.  As a result, the message is routed
to the right location. Each SIP container maintains its own
distinct list of LSIDs.  Therefore, it is imperative that
the Proxy forward the request to the correct Container.

The act of taking the DM up and down results in WLM/UCF being
completely updated.

PROBLEM CONCLUSION:                                             
The problem was that the Proxy forwarded a request to the       
wrong Container, as a result of the to threads of execution     
(traffic handling, DM up and down) managing the data at the     
same time. This has now been corrected.                         
                                                                
The fix for this APAR is currently targeted for inclusion       
in fixpack 6.1.0.9.                                             
Please refer to the recommended updates page for delivery       
information:                                                    
http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980   


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 6.0
__ Application Server (Express or BASE)
__ Network Deployment (ND)
__ WebSphere Business Integration Server Foundation (WBISF)
__ Edge Components
__ Developer
__ Extended Deployment (XD)

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

NOTE:
The user must:
* Have Administrative rights in Windows, or be the Actual Root User in a UNIX environments.
* Logged in with the same authority level when unpacking a fix, fix pack or refresh pack.
* Be at V6.0.2.2 or newer of the Update Installer. This can be checked by reviewing the level of the Update Installer in file <was_root>/updateinstaller/version.txt.

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

For detailed instructions to Extract the Update Installer see the following Technote:
http://www-1.ibm.com/support/docview.wss?rs=180&uid=swg21205400

1) Copy PKxxxxx.pak 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 (PKxxxxx.pak file which was copied in the maintenance 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 (PKxxxxx.pak).

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:  These cumulative fixes are intended for use by ATT only, all other customers should not apply these fixes.  Contact support if you have questions or require an iFix for this issue.