PQ57073: DEADLOCKS WITH DB2/390 USING TX_SERIALIZABLE

 Fixes are available

EJB Container; 4.0.2-4.0.7: Component Cumulative fix for EJB Container
4.0.2-4.0.7: Component cumulative Connection Manager fix



APAR status
Closed as program error.

Error description
Using an isolation level of SERIALIZABLE on container managed
EJBs with DB2/390 as the backend causes missing updates and
SQL0913N Unsuccessful execution caused by deadlock or timeout.
Local fix Problem summary
****************************************************************
* USERS AFFECTED: WebSphere Application Server users of NT,    *
*                 AIX, Linux, Solaris and HP platforms that    *
*                 use a S390 DB2 database.                     *
****************************************************************
* PROBLEM DESCRIPTION: In the case in which a transaction is   *
*                      started by an CMP Entity Bean method.   *
*                      Additionally, the method must have the  *
*                      access intent set to update vs. read    *
*                      only and the isolation level is set to  *
*                      repeatable read.  In this case store    *
*                      operations to the DB2 backend could     *
*                      result in a timeout.                    *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
WebSphere Application Server users of NT, AIX, Linux, Solaris
and HP platforms that use a S390 DB2 database. Additionally,
the CMP's method must start a transaction and have an Access
Intent of Update and have an isolation level of either
Serializable or Repeatable Read.
.
This improvement will detect the backend store is a DB2 390
and refine SQL to avoid this problem.
Problem conclusion
WebSphere users, who encouter a timeout or deadlock situation
with a transaction in update mode with an isolation level of
repeatable read or serializble, when using WebSphere on an NT,
AIX, HP or Solaris platform with S390 DB2, should no longer
have this problem.
Temporary fix Comments
APAR information
APAR number PQ57073
Reported component name WEBSPHERE AE NT
Reported component ID 5630A2201
Reported release 400
Status CLOSED PER
PE NoPE
HIPER NoHIPER
Submitted date 2002-01-24
Closed date 2002-03-21
Last modified date 2002-03-21

APAR is sysrouted FROM one or more of the following:

APAR is sysrouted TO one or more of the following:

Modules/Macros
EJBCONTR          

SRLS

Fix information
Fixed component name WEBSPHERE AE NT
Fixed component ID 5630A2201

Applicable component levels
R400 PSY    UP


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > General
Operating system(s):
Software version: 400
Software edition:
Reference #: PQ57073
IBM Group: Software Group
Modified date: Mar 21, 2002