PQ85099: java.util.ConcurrentModificationException error occurs when Message-Driven Beans are processing messages

 Fixes are available

5.1.1.17: WebSphere Application Server V5.1.1 Cumulative Fix 17 for AIX
5.1.1.17: WebSphere Application Server V5.1.1 Cumulative Fix 17 for HP-UX
5.1.1.19: WebSphere Application Server V5.1.1 Cumulative Fix 19 for Linux
5.1.1.16: WebSphere Application Server V5.1.1 Cumulative Fix 16 for AIX
5.1.1.18: WebSphere Application Server V5.1.1 Cumulative Fix 18 for AIX
5.1.1.18: WebSphere Application Server V5.1.1 Cumulative Fix 18 for HP-UX
5.1.1.18: WebSphere Application Server V5.1.1 Cumulative Fix 18 for Solaris
5.1.1.18: WebSphere Application Server V5.1.1 Cumulative Fix 18 for Windows
5.1.1.18: WebSphere Application Server V5.1.1 Cumulative Fix 18 for Linux
5.1.1.17: WebSphere Application Server V5.1.1 Cumulative Fix 17 for Linux
5.1.1.17: WebSphere Application Server V5.1.1 Cumulative Fix 17 for Solaris
5.1.1.17: WebSphere Application Server V5.1.1 Cumulative Fix 17 for Windows
5.0.2.7: WebSphere Application Server Express 5.0.2 Cumulative Fix 7
5.1.0.5: WebSphere Application Server V5.1.0 Cumulative Fix 5
5.0.2.17: WebSphere Application Server 5.0.2 Cumulative Fix 17 for Solaris
5.0.2.17: WebSphere Application Server 5.0.2 Cumulative Fix 17 for Windows
5.0.2.14: WebSphere Application Server 5.0.2 Cumulative Fix 14 for Solaris
5.1.1.10: WebSphere Application Server V5.1.1 Cumulative Fix 10 for Windows
5.1.1.10: WebSphere Application Server V5.1.1 Cumulative Fix 10 for AIX
5.0.2.14: WebSphere Application Server 5.0.2 Cumulative Fix 14 for Linux
5.1.1.19: WebSphere Application Server V5.1.1 Cumulative Fix 19 for AIX
5.1.1.19: WebSphere Application Server V5.1.1 Cumulative Fix 19 for Windows
5.1.1.9: WebSphere Application Server V5.1.1 Cumulative Fix 9 for Solaris
5.0.2.15: WebSphere Application Server 5.0.2 Cumulative Fix 15 for Windows
5.0.2.15: WebSphere Application Server 5.0.2 Cumulative Fix 15 for Solaris
5.0.2.15: WebSphere Application Server 5.0.2 Cumulative Fix 15 for AIX
5.1.1.9: WebSphere Application Server V5.1.1 Cumulative Fix 9 for AIX
5.0.2.15: WebSphere Application Server 5.0.2 Cumulative Fix 15 for Linux
5.0.2.12: WebSphere Application Server 5.0.2 Cumulative Fix 12
5.0.2.14: WebSphere Application Server 5.0.2 Cumulative Fix 14 for HP-UX
5.0.2.14: WebSphere Application Server 5.0.2 Cumulative Fix 14 for AIX
5.1.1.9: WebSphere Application Server V5.1.1 Cumulative Fix 9 for Windows
5.0.2.17: WebSphere Application Server 5.0.2 Cumulative Fix 17 for HP-UX
5.0.2.17: WebSphere Application Server 5.0.2 Cumulative Fix 17 for AIX
5.1.1.11: WebSphere Application Server V5.1.1 Cumulative Fix 11 for AIX
5.0.2.17: WebSphere Application Server 5.0.2 Cumulative Fix 17 for Linux
5.1.1.10: WebSphere Application Server V5.1.1 Cumulative Fix 10 for HP-UX
5.1.1.10: WebSphere Application Server V5.1.1 Cumulative Fix 10 for Linux
5.1.1.9: WebSphere Application Server V5.1.1 Cumulative Fix 9 for HP-UX
5.1.1.9: WebSphere Application Server V5.1.1 Cumulative Fix 9 for Linux
5.0.2.16: WebSphere Application Server 5.0.2 Cumulative Fix 16 for HP-UX
5.1.1.12: WebSphere Application Server V5.1.1 Cumulative Fix 12 for Windows
5.0.2.16: WebSphere Application Server 5.0.2 Cumulative Fix 16 for Solaris
5.0.2.8: WebSphere Application Server V5.0.2 Cumulative Fix 8
5.0.2.16: WebSphere Application Server 5.0.2 Cumulative Fix 16 for Windows
5.0.2.16: WebSphere Application Server 5.0.2 Cumulative Fix 16 for AIX
5.1.1.11: WebSphere Application Server V5.1.1 Cumulative Fix 11 for Windows
5.1.1.16: WebSphere Application Server V5.1.1 Cumulative Fix 16 for Solaris
5.0.2.18: WebSphere Application Server 5.0.2 Cumulative Fix 18 for Solaris
5.1.1.11: WebSphere Application Server V5.1.1 Cumulative Fix 11 for Linux
5.0.2.18: WebSphere Application Server 5.0.2 Cumulative Fix 18 for Windows
5.0.2.18: WebSphere Application Server 5.0.2 Cumulative Fix 18 for HP-UX
5.0.2.18: WebSphere Application Server 5.0.2 Cumulative Fix 18 for AIX
5.1.1.16: WebSphere Application Server V5.1.1 Cumulative Fix 16 for Windows
5.1.1.14: WebSphere Application Server V5.1.1 Cumulative Fix 14 for Solaris
5.0.2.14: WebSphere Application Server 5.0.2 Cumulative Fix 14 for Windows
5.1.1.12: WebSphere Application Server V5.1.1 Cumulative Fix 12 for AIX
5.1.1.12: WebSphere Application Server V5.1.1 Cumulative Fix 12 for Linux
5.1.1.12: WebSphere Application Server V5.1.1 Cumulative Fix 12 for HP-UX
5.1.1.12: WebSphere Application Server V5.1.1 Cumulative Fix 12 for Solaris
5.1.1.11: WebSphere Application Server V5.1.1 Cumulative Fix 11 for Solaris
5.1.1.13: WebSphere Application Server V5.1.1 Cumulative Fix 13 for AIX
5.1.1.13: WebSphere Application Server V5.1.1 Cumulative Fix 13 for Windows
5.0.2.13: WebSphere Application Server 5.0.2 Cumulative Fix 13
5.1.1.13: WebSphere Application Server V5.1.1 Cumulative Fix 13 for HP-UX
5.1.1.15: WebSphere Application Server V5.1.1 Cumulative Fix 15 for Solaris
5.1.1.13: WebSphere Application Server V5.1.1 Cumulative Fix 13 for Solaris
5.1.1.13: WebSphere Application Server V5.1.1 Cumulative Fix 13 for Linux
5.1.1.14: WebSphere Application Server V5.1.1 Cumulative Fix 14 for AIX
5.1.1.14: WebSphere Application Server V5.1.1 Cumulative Fix 14 for Linux
5.1.1.14: WebSphere Application Server V5.1.1 Cumulative Fix 14 for Windows
5.1.1.15: WebSphere Application Server V5.1.1 Cumulative Fix 15 for Windows
5.1.1: WebSphere Application Server Version 5.1 Fix Pack 1 (Version 5.1.1)
5.0.2.5: WebSphere Application Server 5.0.2 Cumulative Fix 5
5.0.2.18: WebSphere Application Server 5.0.2 Cumulative Fix 18 for Linux
5.1.1.11: WebSphere Application Server V5.1.1 Cumulative Fix 11 for HP-UX
5.1.1.14: WebSphere Application Server V5.1.1 Cumulative Fix 14 for HP-UX
5.0.2.15: WebSphere Application Server 5.0.2 Cumulative Fix 15 for HP-UX
5.0.2.16: WebSphere Application Server 5.0.2 Cumulative Fix 16 for Linux
5.1.1.10: WebSphere Application Server V5.1.1 Cumulative Fix 10 for Solaris
5.1.1.15: WebSphere Application Server V5.1.1 Cumulative Fix 15 for AIX
5.1.1.15: WebSphere Application Server V5.1.1 Cumulative Fix 15 for HP-UX
5.1.1.16: WebSphere Application Server V5.1.1 Cumulative Fix 16 for HP-UX
5.1.1.16: WebSphere Application Server V5.1.1 Cumulative Fix 16 for Linux
5.1.1.15: WebSphere Application Server V5.1.1 Cumulative Fix 15 for Linux
5.1.1.19: WebSphere Application Server V5.1.1 Cumulative Fix 19 for HP-UX



APAR status
Closed as program error.

Error description
When the application server is under heavy load, one or more
Message-Driven Beans stop processing messages, and the following
error appears in the SystemOut.log file:

CNTR0020E: Non-application exception occurred while processing
method "onMessage" on bean <MDB Name>. Exception data:
java.util.ConcurrentModificationException
  at java.util.HashMap$HashIterator.
          nextEntry(HashMap.java(Compiled Code))
  at java.util.HashMap$KeyIterator.
          next(HashMap.java(Compiled Code))
  at com.ibm.ejs.jms.JMSManagedConnection.
          toString(JMSManagedConnection.java(Compiled Code))
Local fix Problem summary
****************************************************************
* USERS AFFECTED: This problem affects customers who use the   *
*                 Java Message Service (JMS) functionality     *
*                 provided with WebSphere Application Server   *
*                 Version 5.x.                                 *
****************************************************************
* PROBLEM DESCRIPTION: When the Application Server is under    *
*                      heavy load, one or more Message-Driven  *
*                      Beans stop processing messages, and     *
*                      the following error appears in the      *
*                      SystemOut.log file:                     *
*                                                              *
*                      CNTR0020E: Non-application exception    *
*                        occurred while processing method      *
*                        "onMessage" on bean <MDB name>.       *
*                        Exception data: java.util.            *
*                        ConcurrentModificationException       *
*                                                              *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
The JMSManagedConnection class contains a field
(openConnectionHandles) that is of type synchronizedSet. When
the class attempts to access this field, it needs to do so
within a synchronized code block, to prevent two or more
threads accessing the field at the same time.

The class implements a toString() method that outputs a
string representation of the JMSManagedConnection object.
However, this method did not access the openConnectionHandles
field from within a synchronized code block - when the
Application Server is running under heavy load, it is possible
that two threads are calling the toString() method at the same
time, and are therefore trying to access the SynchronizedSet
object - this is not permitted, resulting in a
java.util.ConcurrentModificationException error being
generated.
Problem conclusion
The JMSManagedConnection's toString() method has been updated
to access the SynchronizedSet object from a synchronized
code block.
Temporary fix Comments
APAR information
APAR number PQ85099
Reported component name WAS BASE 5.0
Reported component ID 5630A3600
Reported release 10A
Status CLOSED PER
PE NoPE
HIPER NoHIPER
Special Attention NoSpecatt
Submitted date 2004-02-24
Closed date 2004-02-25
Last modified date 2004-02-25

APAR is sysrouted FROM one or more of the following:

APAR is sysrouted TO one or more of the following:

Modules/Macros
msging          

Publications Referenced

Fix information

Applicable component levels
R003 PSY    UP
R00A PSY    UP
R00H PSY    UP
R00I PSY    UP
R00P PSY    UP
R00S PSY    UP
R00W PSY    UP
R103 PSY    UP
R10A PSY    UP
R10H PSY    UP
R10I PSY    UP
R10P PSY    UP
R10S PSY    UP
R10W PSY    UP


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > General
Operating system(s):
Software version: 10A
Software edition:
Reference #: PQ85099
IBM Group: Software Group
Modified date: Feb 25, 2004