PK15537: MULTIPLE VIRTUAL USERS WITH ONE IDENTITY DO NOT REUSE CONNECTIONS IN THE WEBSPHERE FOR Z/OS CONNECTION POOL.

 A fix is available

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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 information
APAR number PK15537
Reported component name WEBSPHERE FOR Z
Reported component ID 5655I3500
Reported release 500
Status CLOSED PER
PE NoPE
HIPER NoHIPER
Special Attention NoSpecatt
Submitted date 2005-11-21
Closed date 2006-03-20
Last modified date 2006-04-05

APAR is sysrouted FROM one or more of the following:

APAR is sysrouted TO one or more of the following:

Modules/Macros
BBOUBINF          

Publications Referenced

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

Applicable component levels
R500 PSY UK12774    UP06/03/24 P F603

  Fix is available
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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