PQ90656: WITH WEBSPHERE ENTERPRISE V5, SCHEDULER TASKS DO NOT RUN CONCURRENTLY DUE TO DATABASE LOCKING PROBLEM

 Fixes are available

Scheduler; 5.0.2.6: Cumulative fix for the Scheduler component
PQ90656; 5.0.2.6: Scheduler tasks do not execute concurrently in 5.0.2 using DB2



APAR status
Closed as program error.

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.
Local fix 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.
Temporary fix Comments
APAR information
APAR number PQ90656
Reported component name WAS ENTERPRISE
Reported component ID 5630A3700
Reported release 00W
Status CLOSED PER
PE NoPE
HIPER NoHIPER
Special Attention NoSpecatt
Submitted date 2004-06-25
Closed date 2004-07-09
Last modified date 2004-07-09

APAR is sysrouted FROM one or more of the following:

APAR is sysrouted TO one or more of the following:

Modules/Macros

Publications Referenced

Fix information

Applicable component levels
R003 PSY    UP
R00A PSY    UP
R00H PSY    UP
R00I PSY    UP
R00S PSY    UP
R00W PSY    UP


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > Enterprise Edition (EE)
Operating system(s):
Software version: 00W
Software edition:
Reference #: PQ90656
IBM Group: Software Group
Modified date: Jul 9, 2004