IBM Support

PK61306; 5 second pauses in BoundedBuffer.waitGet_

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Abstract

With large amounts of processing, unacceptable delays can be observed in the thread pooling code. Javacores show processing threads waiting to be notified in the BoundedBuffer.wait

Download Description

PK61306 resolves the following problem:

ERROR DESCRIPTION:
Thread dumps during pauses like like the following can be viewed for the Consumer thread:

"Consumer : 14" (TID:0x3E153F00, sys_thread_t:0x3CD400E0, state:CW, native ID:0x0008216F) prio=5
at java/lang/Object.wait
at java/lang/Object.wait
at com/ibm/ws/util/BoundedBuffer.waitGet_
at com/ibm/ws/util/BoundedBuffer.poll
at com/ibm/ws/util/ThreadPool.getTask
at com/ibm/ws/util/ThreadPool$Worker.run

USERS AFFECTED:
IBM® WebSphere® Application Server version 6.1 users who are experiencing Service Integration Bus (SIB) processing delays.

PROBLEM DESCRIPTION:
With large amounts of processing, unacceptable delays can be observed in the thread pooling code. Javacores show processing threads waiting to be notified in the BoundedBuffer.waitGet_ method.

PROBLEM SUMMARY:
As a side effect of an optimization, threads in a thread pool never wait indefinitely to be notified when a task is submitted to a thread pool. As part of that optimization, the logic used to determine whether or not a notification should be sent depends on a race condition. Currently, an unnecessarily large time window exists while checking that condition, which can result in larger delays than intended for some tasks submitted to the thread pool.

PROBLEM CONCLUSION:
The time window for the condition is significantly reduced, which improves throughput.
The fix for this APAR is currently targeted for inclusion in fix pack 6.1.0.17.

Please refer to the recommended updates page for delivery information:
http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980

Prerequisites

Please download the UpdateInstaller below to install this fix.

[{"PRLabel":"UpdateInstaller","PRLang":"US English","PRSize":"7250000","PRPlat":{"label":"AIX","code":"PF002"},"PRURL":"http://www.ibm.com/support/docview.wss?rs=180&uid=swg21205991"}]

Installation Instructions

Please review the readme.txt for detailed installation instructions.

[{"INLabel":"Readme","INLang":"US English","INSize":"5740","INURL":"ftp://public.dhe.ibm.com/software/websphere/appserv/support/fixes/PK61306/readme.txt"}]

Download Package

Download package
What is Fix Central (FC)?
What is DD?
Download RELEASE DATE LANGUAGE SIZE(Bytes) Download Options
6.1.0.0-WS-WAS-IFPK613062/26/2008US English10476FCFTPDD

On
[{"DNLabel":"6.1.0.0-WS-WAS-IFPK61306","DNDate":"2/26/2008","DNLang":"US English","DNSize":"10476","DNPlat":{"label":"AIX","code":"PF002"},"DNURL":null,"DNURL_FTP":null,"DDURL":null}]

Technical Support

Contact IBM Support using SR (http://www-306.ibm.com/software/support/probsub.html), visit the WebSphere Application Server Support Web site (http://www.ibm.com/software/webservers/appserv/was/support/), or contact 1-800-IBM-SERV(U.S. only).

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Document Information

Modified date:
15 June 2018

UID

swg24018437