PK52220: CONNECTIONS ARE NOT PURGED FROM THE CONNECTION POOL AFTER THE UNUSED TIMEOUT HITS IF THE SERVANT IS IDLE. | |||||||||||||||||||||||||||||||||||||||
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![]() 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 is sysrouted FROM one or more of the following: APAR is sysrouted TO one or more of the following: PK55370 Modules/Macros Publications Referenced
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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
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