PQ97289: RESOURCE REFERENCE LOOKUP IS NOT THREAD SAFE.

 A fix is available

Obtain the fix for this APAR



APAR status
Closed as program error.

Error description
Resource reference lookup is not thread safe.  During excessive
load the Resource Reference is not found.
.
Corresponding Websphere V5.1 z/os apar 
PQ97290
.
This apar includes fixes from 
PQ97066, 
PQ90851
.
Additional Symptoms:
While running application under load, resource authenctication
may change.  For example, an application running with
resauth=Container may appear to be running with
resauth=Application.
.
From 
PQ97066
Customer application deadlocks or times out with sql0913n on
5.1.1  when application issues a select followed by an update
using shared connections. The resource reference returned is
null causing the res-auth to be different when the
getconnection is issued leading to 2 different connections being
acquired which causes the deadlock in db2.
Local fix
No local fix.
Problem summary
****************************************************************
* USERS AFFECTED: All users of WebSphere Application Server    *
*                 V5.0 for z/OS                                *
****************************************************************
* PROBLEM DESCRIPTION: Resource reference lookup is not thread *
*                      safe.  Resource reference information   *
*                      may be lost during ConnectionFactory or *
*                      DataSource lookup, and as a result      *
*                      incorrect authentication settings,      *
*                      incorrect connection sharing settings,  *
*                      and, for DataSources, incorrect         *
*                      isolation level settings, may be set on *
*                      the ConnectionFactory or DataSource     *
*                      returned to the application.            *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
When performing a lookup of a JMS or JCA ConnectionFactory or a
DataSource in the java:comp/env namespace, using a resource
reference, the lookup may return a ConnectionFactory or
DataSource without the authentication (res-auth), connection
sharing (res-sharing), or isolation level (for DataSources)
information specified on the resource reference.  These
selections, specified as deployment descriptors during
application assembly, may be ignored. The net result would be
the same as if a direct JNDI lookup of the ConnectionFactory
or DataSource was performed, without the resource reference
and using only the defaults for these settings.

So the application may get back a ConnectionFactory or
DataSource with res-auth=Application even though
res-auth=Container was specified on the resource reference.
As one example, this could lead to the servant id used to
get a DB2 JDBC connection rather than the id of the
container-managed alias. This could lead to authorization
failures either getting the connection or accessing the
database tables with the result connection obtained with the
incorrect authorization id.

Or, the application may get back a ConnectionFactory or
DataSource with connection sharing enabled (when unsharable
connections were intended), or vice versa.

Or, the application may get back a DataSource with an incorrect
isolation level (e.g. the default of
java.sql.Connection.TRANSACTION_REPEATABLE_READ), which
could lead to lock contention, poor performance, and deadlocks,
for example.
Problem conclusion
Resource reference lookup has been modified to handle
multithreaded lookups correctly.

APAR PQ97289 is associated with SERVICE LEVEL W502020 of
WebSphere Application Server V5.0 for z/OS.
Temporary fix Comments
APAR information
APAR number PQ97289
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 2004-11-17
Closed date 2004-12-15
Last modified date 2005-01-05

APAR is sysrouted FROM one or more of the following:
PQ90851

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 UQ96100    UP04/12/21 P F412

  Fix is available
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Document Information


Current web document: swg1PQ97289.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 #: PQ97289
IBM Group: Software Group
Modified date: Jan 5, 2005