PQ82145: CONCURRENTMODIFICATIONEXCEPTION DURING DB2 MANAGED CONNECTION CLOSE ON WEBSPHERE FOR Z/OS V4.0.1.

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APAR status
Closed as program error.

Error description
Customer receives the following exception in the server region
when a connection is closed by their application,
.
java.util.ConcurrentModificationException
.at java.util.LinkedList$ListItr.checkForComodification
.at java.util.LinkedList$ListItr.next
.at com.ibm.connector2.ws390.db2jdbc.DB2JDBCManagedConnection
                                                       .close
.at com.ibm.connector2.ws390.db2jdbc.DB2JDBCConnectionHandle.
close(DB2JDBCConnectionHandle.java:106)
.
Local fix Problem summary
****************************************************************
* USERS AFFECTED: All users of WebSphere Application Server    *
*                 version 4.0.1 for z/OS and OS/390.           *
****************************************************************
* PROBLEM DESCRIPTION: ConcurrentModificationException thrown  *
*                      when doing a Connection.close() on a    *
*                      DB2 JDBC Connection handle from an      *
*                      application.                            *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
The problem occurs on a path in which an application issues a
Connection.close() on a DB2 JDBC Connection handle.  During the
close path, Connection Management decides to destroy the
ManagedConnection object instead of returning it to the
connection pool, because the pool is at its maximum size. The
destroy path triggers the ConcurrentModificationException due
to a problem with the DB2JDBCManagedConnection's
ConnectionEventListener processing.

The exception stack trace in detail:

java.util.ConcurrentModificationException
 at java.util.LinkedList$ListItr.checkForComodification
 at java.util.LinkedList$ListItr.next
 at com.ibm.connector2.ws390.db2jdbc.DB2JDBCManagedConnection.
    close(DB2JDBCManagedConnection.java:399)
 at com.ibm.connector2.ws390.db2jdbc.DB2JDBCConnectionHandle.
    close(DB2JDBCConnectionHandle.java:106)
 ....
Problem conclusion
Fix made in ConnectionEventListener processing and cleanup
processing in DB2JDBCManagedConnection class.

APAR PQ82145 is associated with SERVICE LEVEL W401610 of
WebSphere Application Server version 4.0.1 for z/OS and OS/390.
Temporary fix Comments
APAR information
APAR number PQ82145
Reported component name WASKBASE
Reported component ID 5655A9801
Reported release 401
Status CLOSED PER
PE NoPE
HIPER NoHIPER
Submitted date 2003-12-12
Closed date 2004-03-12
Last modified date 2004-04-03

APAR is sysrouted FROM one or more of the following:

APAR is sysrouted TO one or more of the following:
UQ86140

Modules/Macros
BBODMN BBOMSBO2 BBOOCTL BBOUBINF BBOUENUS BBOWCPYR
BBOWHSY3 BBOWSYS3 BBOW01 BBOZ0229 BBOZ0812 BBOZ0813
BBOZ0977          

Fix information
Fixed component name WASKBASE
Fixed component ID 5655A9801

Applicable component levels
R401 PSY UQ86140    UP04/03/23 P F403

  Fix is available
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Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server for z/OS
Operating system(s):
Software version: 401
Software edition:
Reference #: PQ82145
IBM Group: Software Group
Modified date: Apr 3, 2004