PM16027: DRS THREADS COME FROM THE DEFAULT THREAD POOL, INSTEAD OF FROM A NAMED THREAD POOL SPECIFIC TO DRS.

Fixes are available

APAR status

Closed as program error.

Error description

DRS consumes threads from the default thread pool for processing
incoming messages. It is difficult to tell which thread pool
threads belong to DRS.  DRS should have its own named thread
pool.

Local fix

Problem summary

****************************************************************
* USERS AFFECTED:  All users of IBM WebSphere Application      *
*                  Server V6.1.0 using Data Replication        *
*                  Services (DRS).                             *
****************************************************************
* PROBLEM DESCRIPTION: Threads from the "Default" thread       *
*                      pool become exhausted preventing        *
*                      DRS or other users of the pool          *
*                      from obtaining a thread.                *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
DRS uses threads from the "Default" thread pool for
deserializing replication messages, passing messages to DRS
consumers and creating servant change listeners on zOS.  In a
high volume environment DRS may consumer a majority of the
threads and prevent other application server components from
obtaining a thread from the pool.

Problem conclusion

DRS has been modified to create its own thread pool at server
startup.  The thread pool will be used exclusively by DRS and
its consumers. This APAR introduces 3 JVM custom properties
to set the minimum and maximum size of the thread pool and set
the growable flag:

DRS_THREADPOOL_MINSIZE default is 40
DRS_THREADPOOL_MAXSIZE default is 100
DRS_THREADPOOL_ISGROWABLE default false

APAR PM16027 requires changes to documentation.

NOTE: Periodically, we refresh the documentation on our
Web site, so the changes might have been made before you
read this text. To access the latest on-line
documentation, go to the product library page at:

http://www.ibm.com/software/webservers/appserv/library

The following Change to the WebSphere Application
Server Version  6.1.x Information Center
will be made available in December 2010.

Step 3 in the topic "Replicating data across application
servers in a cluster" will be updated to include the
following information:

Starting with Fix Pack 6.1.0.35, the replication service
uses threads that are obtained from the DRS thread pool
for various tasks, including processing messages.
Previously, the replication service obtained threads from
the default thread pool. When the application server
starts up, the default maximum thread pool size for the
DRS thread pool is 100 threads. However, this thread pool
size might not be sufficient to enable the replication
service to obtain enough threads from the pool to process
all of the incoming replication messages. The number of
incoming messages is influenced by the number of
application servers in the domain and the number of
replication domain consumers on each application server.
The number of messages to be processed increases as the
number of application servers in the domain increases,
the number of replication consumers increases, or both.

Persistent data that is not being replicated to the
application servers when the application server starts
up might indicate that you need to increase the setting
for the maximum thread pool size. The maximum size of the
DRS thread pool set to 100 is usually sufficient. However,
in very large topologies, you might need to set the
maximum thread pool size to a value that is greater than
100.

Table 1. DRS thread pool custom properties.

You can set the properties of the DRS thread pool through
the following Java virtual machine custom properties.
Property name               Default value
DRS_THREADPOOL_MINSIZE       40
DRS_THREADPOOL_MAXSIZE       100
DRS_THREADPOOL_ISGROWABLE       false

For more information, see the documentation about Java
virtual machine custom properties.

APAR PM16027 is currently targeted for inclusion in Service
Level (Fix Pack) 6.1.0.35 of WebSphere Application Server V6.1.

Please refer to URL:
//www.ibm.com/support/docview.wss?rs=404&uid=swg27006970
for Fix Pack availability.

Temporary fix

Comments

APAR Information

APAR number
PM16027
Reported component name
WEBSPHERE FOR Z
Reported component ID
5655I3500
Reported release
610
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2010-06-07
Closed date
2010-07-28
Last modified date
2011-01-03

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

PM16028

Fix information

Fixed component name
WEBSPHERE FOR Z
Fixed component ID
5655I3500

Applicable component levels

R610 PSY UK62676
UP10/12/17 P F012

Fix is available

Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.

[{"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SS7K4U","label":"WebSphere Application Server for z\/OS"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"6.1","Line of Business":{"code":"LOB45","label":"Automation"}}]

Document Information

Modified date:
25 October 2021

Tips

PM16027: DRS THREADS COME FROM THE DEFAULT THREAD POOL, INSTEAD OF FROM A NAMED THREAD POOL SPECIFIC TO DRS.

Fixes are available

Subscribe

APAR status

Closed as program error.

Error description

Local fix

Problem summary

Problem conclusion

Temporary fix

Comments

APAR Information

APAR number

Reported component name

Reported component ID

Reported release

Status

PE

HIPER

Special Attention

Submitted date

Closed date

Last modified date

APAR is sysrouted FROM one or more of the following:

APAR is sysrouted TO one or more of the following:

Fix information

Fixed component name

Fixed component ID

Applicable component levels

R610 PSY UK62676

Fix is available

Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.

Document Information

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