PK02976; 5.1.1.3: JAVA Message service listener port deadlock
 Downloadable files
 
Abstract
JAVA Message service listener port deadlock after queue manager restart.
 
Download Description
PK02976 resolves the following problem:

ERROR DESCRIPTION:
After the Queue Manager is restarted, the JMS listener port is jammed resulting in a deadlock situation.

There seems to be a problem with the messagingImpl.jar file in the classes directory.

LOCAL FIX:
There seems to be a problem in the messagingImpl.jar file in the classes directory. A new version of messagingImpl.jar was created, which has resolved this issue for the customer.

PROBLEM SUMMARY:

USERS AFFECTED:
This problem affects customers who use the Java Message Service (JMS) functionality provided with WebSphere Application Server Version 5.0.2 and 5.1.1.

PROBLEM DESCRIPTION:
After a Queue Manager restart, the following error messages appear in the WebSphere Application Server system log :
JMSExceptionL E WMSG0018E: Error on JMSConnection for MDB merctopicMDBBean , JMSDestination
jms/MERC.JMS.TOPIC : javax.jms.JMSException: MQJMS2002: failed to get message from MQ queue
at com.ibm.mq.jms.services. ConfigEnvironment.newException (ConfigEnvironment.java(Inlined Compiled Code))
at com.ibm.mq.jms.MQQueueAgentThread. browse (MQQueueAgentThread.java(Compiled Code)) at com.ibm.mq.jms.MQQueueAgentThread.run (MQQueueAgentThread.java(Compiled Code))
at java.lang.Thread.run(Thread.java:568)

RECOMMENDATION:
In this situation, we have two threads involved in a Deadlock situation on a synchronized set within the code. As part of the Listener shutdown process, the JMSManagedConnection code locks a synchronized set which has a list of registered connections event listeners. After obtaining a lock, the JMSManagedConnection code calls in to our JCA code which in turn tries to reference the already locked synchronized set. Thus the two threads wait for each other in a deadlock.

PROBLEM CONCLUSION:
To get around this problem, we create a copy of the synchronised set and allow one thread to work on the copy of the freeing the threads from a deadlock situation.

The fix for this APAR is currently targeted for inclusion in Cumulative Fix 11 for WebSphere Application Server Version 5.0.2, Cumulative Fix 5 for WebSphere Application Server Version 5.1.1. and Cumulative Fix 2 for WebSphere Application Server Version 6.0.1.

Please refer to the Recommended Updates page for delivery dates:
http://www.ibm.com/support/docview.wss?&context=SSEQTP&uid=swg27004980
 
Prerequisites
Please download the UpdateInstaller below to install this fix.
 
URL LANGUAGE SIZE(Bytes)
UpdateInstaller US English 7250000
 
 
Installation Instructions
Please review the readme.txt for detailed installation instructions.
 
URL LANGUAGE SIZE(Bytes)
Readme US English 3327
 
Download package
What is DD?
Download RELEASE DATE LANGUAGE SIZE(Bytes) Download Options
PK02976_50210.jar 5/27/2005 US English 394932 FTP DD
PK02976_5029.jar 5/27/2005 US English 395035 FTP DD
PK02976_5027.jar 5/27/2005 US English 405958 FTP DD
PK02976_5104.jar 5/27/2005 US English 404991 FTP DD
PK02976_5110.jar 5/27/2005 US English 405958 FTP DD
PK02976_5111.jar 5/27/2005 US English 403769 FTP DD
PK02976_5112.jar 5/27/2005 US English 404991 FTP DD
PK02976_5113.jar 5/27/2005 US English 404309 FTP DD
PK02976_5114.jar 6/2/2005 US English 405926 FTP DD
 
Technical support
1-800-IBM-SERV (U.S. Only)
 
Cross Reference information
Segment Product Component Platform Version Edition
Application Servers Runtimes for Java Technology Java SDK
Problems (APARS) fixed
PK02976, PK01477, PQ99224, PK00582
 
 


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server
Operating system(s): Windows
Software version: 5.1.1.3
Software edition:
Reference #: 4009779
IBM Group: Software Group
Modified date: Jun 2, 2005