PK15537: MULTIPLE VIRTUAL USERS WITH ONE IDENTITY DO NOT REUSE CONNECTIONS IN THE WEBSPHERE FOR Z/OS CONNECTION POOL. | |||||||||||||||||||||||||||||||||||||||||||
![]() |
|||||||||||||||||||||||||||||||||||||||||||
![]() APAR status Closed as program error. Error description Multiple virtual users with one identity do not reuse connections in the WebSphere for z/OS connection pool. This apar will address this issue.Local fix Problem summary **************************************************************** * USERS AFFECTED: All users of WebSphere Application Server * * V5.0 for z/OS * **************************************************************** * PROBLEM DESCRIPTION: When ThreadIdentitySupport is used * * with a ConnectionFactory or * * a DataSource, connections in the * * connection FreePool that are still * * associated with a particular user * * are not properly being reused to * * satisfy connection requests * * by the same user. As a result, the * * maximum connection limit will be * * reached and connection request * * processing will experience increased * * overhead thereby affecting * * performance. There are no visible * * external symptoms. * **************************************************************** * RECOMMENDATION: * **************************************************************** When ThreadIdentitySupport is used with a DataSource or ConnectionFactory to associate the caller's userid with a connection, connections in the FreePool that were previously used by the user are not always being reused to satisfy subsequent connection requests as they should be. As this occurs repeatedly, the number of connections in use will grow until the maximum connection limit is reached. Once the maximum connection limit is reached, failure to find a matching connection in the freepool for a current connection request will result in an available freepool connection being closed down to drop the connection in-use count and then a new connection will be obtained from the DataSource or ConnectionFactory. Because this is an expensive process, performance will be impacted negatively. This problem occurs because the user credentials associated with an existing free connection and the user credentials associated with a new getConnection request are not being compared properly. As a result, even though a connection in the FreePool should be a good match for reuse, the comparison fails.Problem conclusion The comparison of credentials when searching for a matching connection in the FreePool will be changed to properly detect a matching connection. APAR PK15537 is associated with SERVICE LEVEL W502039 of WebSphere Application Server V5.0 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: Modules/Macros
Publications Referenced
|
Document Information |
Current web document: swg1PK15537.html
Product categories: Software > Application Servers >
Distributed Application & Web Servers > WebSphere Application
Server for z/OS
Operating system(s):
Software version: 500
Software edition:
Reference #: PK15537
IBM Group: Software Group
Modified date: Apr 5, 2006
(C) Copyright IBM Corporation 2000, 2009. All Rights Reserved.