PM54323: WITH ERRORDETECTIONMODEL SET TO EXCEPTIONMAPPING CONNECTION POOL DOES NOT GET PURGED IN RARE CASE

Fixes are available

APAR status

Closed as program error.

Error description

With errorDetectionModel set to ExceptionMapping and
terminate the database connections ( negative test case)
using " db2 force applications all" the JDBC Driver throws
an XAException during start of UOW.

This exception is caught by the WebSphere RRA code and
a StaleConnectionException is instantiated. Since the SCE
was instantiated, the existing code does not have the
functionality to fire the connection error event and
thereby the connection pool does not get purged.

But in the case of errorDetectionModel set to
ExceptionChecking, the above scenario results in
the connection pool getting purged.

Local fix

Problem summary

****************************************************************
* USERS AFFECTED:  All users of IBM WebSphere Application      *
*                  Server                                      *
****************************************************************
* PROBLEM DESCRIPTION: With errorDetectionModel set to         *
*                      ExceptionMapping the connection pool    *
*                      does not get purged in rare cases       *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
When the connection pool error detection model is configured to
exception mapping, the stale connection exception indicates
that the connection is no longer valid. Consider the scenario
where the DB2 database connections are terminated using "db2
force applications all" command and the JDBC Driver throws an
XAException during start of UOW. This exception is caught by
the WebSphere RRA code and a StaleConnectionException is
instantiated and thrown back to the application.
Typically when a StaleConnectionException results from the
exception mapping process a connection error event is fired and
subsequently the connection pool gets purged.  However in this
rare case scenario the SCE is instantiated, but does
not fire the connection error event for the pool to get purged.
When connections are terminated at the database side,
upon requesting a new connection, the driver throws an
XAException. Under such condition, with
errorDetectionModel=ExceptionMapping, you observe connection
pool not getting purged, then with this apar you can force a
ConnectionErrorEvent to be fired so that the connection pool
gets purged based on the purge policy.
Note : The APAR is not enabled by default and in order to
enable the APAR you will have to define a datasource custom
property on the respective datasources
Navigate to:
Resources > JDBC > JDBC providers > JDBC_provider > Data
sources > (data_source) > Custom properties
Define the following custom property :
Property Name : fireCEEventOnSCE
Value : true
Restart the servers for the custom property to take effect.

Problem conclusion

The WebSphere RRA code has been changed such that the pool
purged properly upon a StaleConnectionException when using
ExceptionMapping as the errorDetection model.
The fix for this APAR is currently targeted for inclusion in
fix packs 7.0.0.23 and 8.0.0.4.  Please refer to the
Recommended Updates page for delivery information:
http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980

Temporary fix

Comments

APAR Information

APAR number
PM54323
Reported component name
WEBS APP SERV N
Reported component ID
5724H8800
Reported release
700
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2011-12-14
Closed date
2012-03-28
Last modified date
2016-02-02

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

Fix information

Fixed component name
WEBS APP SERV N
Fixed component ID
5724H8800

Applicable component levels

R700 PSY
UP
R800 PSY
UP

[{"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SSEQTP","label":"WebSphere Application Server"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"7.0","Line of Business":{"code":"LOB45","label":"Automation"}}]

Document Information

Modified date:
28 October 2021

Tips

PM54323: WITH ERRORDETECTIONMODEL SET TO EXCEPTIONMAPPING CONNECTION POOL DOES NOT GET PURGED IN RARE CASE

Fixes are available

Subscribe

APAR status

Closed as program error.

Error description

Local fix

Problem summary

Problem conclusion

Temporary fix

Comments

APAR Information

APAR number

Reported component name

Reported component ID

Reported release

Status

PE

HIPER

Special Attention

Submitted date

Closed date

Last modified date

APAR is sysrouted FROM one or more of the following:

APAR is sysrouted TO one or more of the following:

Fix information

Fixed component name

Fixed component ID

Applicable component levels

R700 PSY

R800 PSY

Document Information

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