A fix is 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 V7.0 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 PM16028 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 7.0 Information Center will be made available in October 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 7.0.0.13, 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 PM16028 is currently targeted for inclusion in Service Level (Fix Pack) 7.0.0.13 of WebSphere Application Server V7.0. 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
PM16028
Reported component name
WEBSPHERE FOR Z
Reported component ID
5655I3500
Reported release
700
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2010-06-07
Closed date
2010-07-28
Last modified date
2010-11-03
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
WEBSPHERE FOR Z
Fixed component ID
5655I3500
Applicable component levels
R700 PSY UK61114
UP10/10/21 P F010
Fix is available
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Document Information
Modified date:
10 February 2022