PK52220: CONNECTIONS ARE NOT PURGED FROM THE CONNECTION POOL AFTER THE UNUSED TIMEOUT HITS IF THE SERVANT IS IDLE.

 Fixes are available

6.1.0.15 WebSphere Application Server V6.1 Fix Pack 15 for i5/OS
6.0.2.25: WebSphere Application Server V6.0.2 Fix Pack 25 for AIX platforms
6.0.2.27: WebSphere Application Server V6.0.2 Fix Pack 27 for HP-UX platforms
6.1.0.15 WebSphere Application Server V6.1 Fix Pack 15 for AIX
6.1.0.15: WebSphere Application Server V6.1 Fix Pack 15 for HP-UX
6.1.0.15: WebSphere Application Server V6.1 Fix Pack 15 for Windows
6.0.2.27: WebSphere Application Server V6.0.2 Fix Pack 27 for OS/400 platform
6.1.0.17 WebSphere Application Server V6.1 Fix Pack 17 for i5/OS
6.0.2.27: WebSphere Application Server V6.0.2 Fix Pack 27 for Solaris
6.0.2.27: WebSphere Application Server V6.0.2 Fix Pack 27 for Windows platforms
6.1.0.17: WebSphere Application Server V6.1 Fix Pack 17 for Linux
6.0.2.27: WebSphere Application Server V6.0.2 Fix Pack 27 for AIX platforms
6.0.2.25: WebSphere Application Server V6.0.2 Fix Pack 25 for HP-UX platforms
6.1.0.17: WebSphere Application Server V6.1 Fix Pack 17 for Solaris
6.1.0.17: WebSphere Application Server V6.1 Fix Pack 17 for HP-UX
6.1.0.17: WebSphere Application Server V6.1 Fix Pack 17 for Windows
6.1.0.17 WebSphere Application Server V6.1 Fix Pack 17 for AIX
6.1.0.15: WebSphere Application Server V6.1 Fix Pack 15 for Linux
6.1.0.15: WebSphere Application Server V6.1 Fix Pack 15 for Solaris
6.0.2.29: WebSphere Application Server V6.0.2 Fix Pack 29 for AIX platforms
6.0.2.29: WebSphere Application Server V6.0.2 Fix Pack 29 for HP-UX platforms
6.0.2.29: WebSphere Application Server V6.0.2 Fix Pack 29 for Linux platforms
V6.0.2: Java SDK 1.4.2 SR11 Cumulative Fix for IBM WebSphere Application Server
6.0.2.29: WebSphere Application Server V6.0.2 Fix Pack 29 for Solaris
6.0.2.29: WebSphere Application Server V6.0.2 Fix Pack 29 for Windows platforms
6.0.2.27: WebSphere Application Server V6.0.2 Fix Pack 27 for Linux platforms
6.0.2.25: WebSphere Application Server V6.0.2 Fix Pack 25 for Linux platforms
6.0.2.25: WebSphere Application Server V6.0.2 Fix Pack 25 for Solaris
6.0.2.25: WebSphere Application Server V6.0.2 Fix Pack 25 for Windows platforms
6.1.0.19 WebSphere Application Server V6.1 Fix Pack 19 for AIX
6.1.0.19: WebSphere Application Server V6.1 Fix Pack 19 for HP-UX
6.1.0.19 WebSphere Application Server V6.1 Fix Pack 19 for i5/OS
6.1.0.19: WebSphere Application Server V6.1 Fix Pack 19 for Linux
6.1.0.19: WebSphere Application Server V6.1 Fix Pack 19 for Solaris
6.1.0.19: WebSphere Application Server V6.1 Fix Pack 19 for Windows
Java SDK 1.5 SR8 Cumulative Fix for WebSphere Application Server
6.0.2.31: WebSphere Application Server V6.0.2 Fix Pack 31 for AIX platforms
6.0.2.31: WebSphere Application Server V6.0.2 Fix Pack 31 for HP-UX platforms
6.0.2.31: WebSphere Application Server V6.0.2 Fix Pack 31 for OS/400 platform
6.0.2.31: WebSphere Application Server V6.0.2 Fix Pack 31 for Linux platforms
6.0.2.31: WebSphere Application Server V6.0.2 Fix Pack 31 for Solaris
6.0.2.31: WebSphere Application Server V6.0.2 Fix Pack 31 for Windows platforms
V6.0.2: Java SDK 1.4.2 SR11 Cumulative Fix for IBM WebSphere Application Server



APAR status
Closed as program error.

Error description
WebSphere uses alarm managers to calculate the unused timeout
and start the reaper thread to clean up connections from the
pool. Since a deferrable alarm is used, in order to save CPU
when the servant is idle, if there are connections in the pool
left once the servant becomes idle these are not cleaned up.
These are cleaned up only when work enters the servant again.
This apar will provide a property to control this behavior and
give the option to cleanup threads as the unused timeout hits
regardless of work entering the servant.
Local fix Problem summary
****************************************************************
* USERS AFFECTED: All users of WebSphere Application Server    *
*                 V6.0.1 for z/OS                              *
****************************************************************
* PROBLEM DESCRIPTION: Unused connections are not discarded    *
*                      even though unused timeout has passed.  *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
Reap time and unused timeout settings do not cause the idle or
unused connections to be discarded if the servant region is
idle. This may cause some DB2 connections to be tied up for a
longer time than necessary.
Problem conclusion
Users that prefer to discard connections at the time they
specified by combination of  reaper time and unused timeout
settings even if it may cause an idle servant region to become
active again, receive an option to do it by setting a new
datasource custom property.

To select this behavior, create a custom datasource propery
'nondeferredreaper' of type java.lang.Boolean, set its value
to 'true' for a specific datasource, and restart the server.
For instance, when using the administrative console use the
following links:
JDBC providers > DB2 Universal JDBC Driver Provider > Data
sources > <specific datasource> > Custom properties > New
Name: nondeferredreaper  Value: true Type: java.lang.Boolean

Users that choose to set this up, need to be aware that
activating an idle servant region for a sole purpose of
discarding unused connection, may cause additional and
sometimes undesirable CPU usage. Also, a following warning
might be logged and should be ignored:
DSRA8200W: DataSource Configuration:
DSRA8020E: Warning: The property 'nondeferredreaper' does not
exist on the DataSource class
com.ibm.db2.jcc.DB2ConnectionPoolDataSource.

For users that prefer to stay with the current behavior, this
APAR is not going to change it, unless 'nondeferredreaper'
custom property is added and set to 'true'.

APAR PK52220 requires changes to documentation.

NOTE: Periodically, we refresh the documentation on our
Web site, so the changes might have been made before you
read this text. To access the latest on-line
documentation, go to the product library page at:


http://www.ibm.com/software/webservers/appserv/library

The following changes to the z/OS version of the WebSphere
Application Server Version 6.0.x Information Center will be
made available.

The topic "Tuning connection pools" will be updated
to include the following descriptions of the new
nondeferredreaper custom properties:

Discard connections. Reap time and unused timeout settings
do not cause the idle or unused connections to be discarded
if the servant region is idle. This situation might
cause some DB2 connections to be held longer than is
necessary.

If you prefer to have the connections discarded at the
time specified by a combination of  reaper time and unused
timeout settings, even if this preference might cause an
idle servant region to become active again, you can
add the new nondeferredreaper custom property to your
JDBC driver provider data source settings. When you
add this custom property, connections are discarded at the
time specified by a combination of reaper time and
unused timeout settings.

To add this custom property to your JDBC dDriver provider
data source settings, in the administrative console,
click Resources > JDBC providers > DB2 Universal JDBC
Driver Provider > Data sources > datasource_name >
Custom properties > New. Then specify nondeferredreaper
in the Name field, true in the Value field, and
java.lang.Boolean in the Type field. This new setting does
not go into affect until you restart the server that is
using this datasource.

Note: Activating an idle servant region for the sole purpose
of discarding unused connection, might cause additional and
sometimes undesirable CPU usage. Also, a following warning
might be logged and should be ignored:
DSRA8200W: DataSource Configuration:
DSRA8020E: Warning: The property 'nondeferredreaper' does not
exist on the DataSource class
com.ibm.db2.jcc.DB2ConnectionPoolDataSource.

APAR PK52220 currently targeted for inclusion in Service
Level (Fix Pack) 6.0.2.24 of WebSphere Application Server V6.0.1
for z/OS.
Temporary fix Comments
APAR information
APAR number PK52220
Reported component name WEBSPHERE FOR Z
Reported component ID 5655I3500
Reported release 601
Status CLOSED PER
PE NoPE
HIPER NoHIPER
Special Attention NoSpecatt
Submitted date 2007-09-04
Closed date 2007-11-06
Last modified date 2008-02-13

APAR is sysrouted FROM one or more of the following:

APAR is sysrouted TO one or more of the following:
PK55370

Modules/Macros

Publications Referenced

Fix information
Fixed component name WEBSPHERE FOR Z
Fixed component ID 5655I3500

Applicable component levels
R500 PSN    UP
R601 PSY UK31684    UP07/12/04 P F712
R610 PSN    UP

  Fix is available
Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.


Document Information


Current web document: swg1PK52220.html
Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server for z/OS
Operating system(s):
Software version: 601
Software edition:
Reference #: PK52220
IBM Group: Software Group
Modified date: Feb 13, 2008