PQ90656; 5.0.2.6: Scheduler tasks do not execute concurrently in 5.0.2 using DB2
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Abstract
In incorrout with WebSphere Enterprise V5. Scheduler tasks do not run concurrently due to database locking problem.
 
Download Description
PQ90656 resolves the following problem:

ERROR DESCRIPTION:
Using the Scheduler Service in WebSphere Application V5 Enterprise Edition, when multiple tasks are scheduled to run at the same time, it may be observed that the tasks will only run sequentially and not concurrently.

This occurs when DB2 V7 is used for the Scheduler database table. The Scheduler poll daemon is blocked by an update to an index value by the currently executing task. Because of this, new tasks cannot run until the currently executing task is completed.

PROBLEM SUMMARY:

USERS AFFECTED:
All WebSphere Enterprise 5.0 Scheduler users using DB2

PROBLEM DESCRIPTION:
Scheduler tasks do not execute concurrently in 5.0.2 using DB2

RECOMMENDATION:
Apply intermediate fix PQ90656 to 5.0.2.
The Scheduler poll daemon will block when any scheduled tasks are executing and the scheduler is configured to use DB2 as a backend database. This will result in each task running serially instead of concurrently. This behavior is seen predominantly when tasks run for a long period of time.

PROBLEM CONCLUSION:
The Scheduler has been changed such that the poll daemon will now read records using TRANSACTION_READ_UNCOMMITTED isolation level. In addition, customers must use the DB2 setting "DB2_RR_TO_RS=Yes" to take advantage of this fix.
 
Prerequisites
Please download the UpdateInstaller below to install this fix.
 
URL LANGUAGE SIZE(Bytes)
UpdateInstaller US English 7250000
 
 
Installation instructions
Please review the readme.txt for detailed installation instructions.
 
URL LANGUAGE SIZE(Bytes)
Readme US English 2048
 
Download package
What is DD?
DOWNLOAD RELEASE DATE LANGUAGE SIZE(Bytes) Download Options
PQ90656.jar 3/4/2005 US English 49052 FTP DD
 
Technical support
1-800-IBM-SERV (U.S. Only)
 
Cross Reference information
Segment Product Component Platform Version Edition
Application Servers Runtimes for Java Technology Java SDK
Problems (APARs) fixed
PQ90656
 
 


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > Programming Model Extensions (PME)
Operating system(s): Windows
Software version: 5.0.2.6
Software edition:
Reference #: 4009067
IBM Group: Software Group
Modified date: Apr 14, 2005