Fix (APAR):  PQ96203

Status:  Fix

Release:  4.0.7,4.0.6,4.0.5

Operating System:  All

Supersedes Fixes:  Pre-requisite Fixes:

CMVC Defect:  PQ96203

Byte size of APAR:  1072764

Date: 2004-11-02

Abstract:  JMSEXCEPTION MQJMS1068: FAILED TO OBTAIN XARESOURCE

Description/symptom of problem:  
Environment:
WAS 4.0.5, EE 4.1
WAS MQ 5.3
Short Description:
J2EE application sometimes fails to place mesage using JMS
into WebSphere MQ
Exceptions from application's log:
2004-06-28 22:19:14,738 DEBUG [Thread-28] ipgw.mdb.
IpgwMatchMDBClientBean sendNewBlockFile: got JMSException
[MQJMS1068: failed to obtain XAResource]
javax.jms.JMSException: MQJMS1068: failed to obtain XAResource
at
com.ibm.mq.jms.services.ConfigEnvironment.newException
(ConfigEnvironment.java:540)
at
com.ibm.mq.jms.MQXAQueueConnection.createXAQueueSession
(MQXAQueueConnection.java:96)
at com.ibm.ejs.jms.mq.JMSWrapXAQueueConnection.
internalCreateXAQueueSession(JMSWrapXAQueueConnection.java:309
)
at
com.ibm.ejs.jms.mq.JMSWrapXAQueueSession.createXASession
(JMSWrapXAQueueSession.java:355)
...
The problem was triggered by "XA operation failed" error
(javax.transaction.xa.XAException) with error code -8
(which is XAER_DUPID, or duplicate XA id).
WebSphere uses identityHashCode to generate the unique XID.
When two objects return the same identityHashCode, WebSphere
generates non-unique XIDs.

This fix replaces the use of identityHashCode to generate the
branch qualifies with a counter, which is incremeneted for each
resource taking part in transaction.



Directions to apply fix:  

1) Create temporary "fix" directory to store the jar file:
                  AIX: /tmp/WebSphere/fix
                  Solaris/Linux: /tmp/WebSphere/fix
                  Windows: c:\temp\WebSphere\fix

2) Copy jar file to the directory

3) 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.

4) Run the jar file with the following command answering questions/prompts as they appear:
   java -jar PQ96203_Fix.jar

5) Restart WebSphere

6) The temp directory may be removed but the jar file should be saved.  Do not remove
   any files created and stored in the <WASHOME>/WebSphere/AppServer/fix/<fix> directories.
   These files are required if a fix is to be removed.



Directions to remove fix:  

NOTE:  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) Change directory to the fix location (<WASHOME>/WebSphere/AppServer/fix/<fix#>).

2) 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.

3) Run the backup jar file with the following command:
   java -jar PQ96203_Fix_backup.jar

4) Restart WebSphere



Directions to re-apply fix:  
Follow the instructions for applying a fix.

If the backup files still exist (from the previous fix application), you will be prompted to overwrite.

Answer "yes" at the overwrite prompts.



Additional Information: