PK09021: THE NUMBER OF"COM/IBM/WS/WEBCONTAINER/SRT/WEBAPPINVOKER" OBJECTSIS ALMOST DOUBLE THE NUMBER OF THE INVOCATION CACHE SETTING | |||||||||||||||||||||||||||||||||||||||||||
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![]() APAR status Closed as program error. Error description In WSAS 5.X, Upon Analyisis of the HeapDump we notice the number of"com/ibm/ws/webcontainer/srt/WebAppInvoker" objects grow over a period of time, The number is almost double the number of the invocation cache setting. Details : The default invocation cache setting is 50 for each webcontainer thread and the deafult webcontainer thread pool is 50. so at any given point you should see no more than 2500 entries. but Analysis of Hepadumps, taken during Peak load suggest that there are close to 5000 entires One cache entry loosely equates to one " com/ibm/ws/webcontainer/srt/WebAppInvoker" object Here is the standard formula to calculate the cache entries V 5.X If the thread pool size is set to P and invocation cache size is set to C, the total number of cached WebAppInvoker is (2 * P + 1) * C V 4.X The total number is (P + 1) * C In V5, it approximately doubled the number of cached objects comparing to V4 or calculated number. Reason for increase in V5.X: The reason of the increase is that, in V5, the number of request processors created by transport is (2 * P + 1) and each processor has an invocation cache of up to C cached objects. . This APAR also addresses distributed APAR PK05604Local fix no Work Around available at this timeProblem summary **************************************************************** * USERS AFFECTED: All users of WebSphere Application Server * * V5.0 for z/OS * **************************************************************** * PROBLEM DESCRIPTION: Analysis of a v5.0 HeapDump * * after a peak load run showed * * that there was a huge number of * * "com/ibm/ws/webcontainer/srt/ * * WebAppInvoker" objects that grew over * * a period of time. * **************************************************************** * RECOMMENDATION: * **************************************************************** The default invocation cache setting is 50 for each webcontainer thread and the default webcontainer thread pool is 50. So, at any given point you should see no more than 2500 entries but analysis of Heapdumps taken during peak load suggest that there are close to 5000 entires. One cache entry equates to about one "com/ibm/ws/webcontainer/srt/WebAppInvoker" object. These cached objects are doubled which consumed more memory than in v4. The formula for v5, cached objects = #threads * cache size was not held.Problem conclusion The code was modified to detach the invocation cache from the SRPRequestProcessor. It is purely thread based so that only the maximum thread number of caches will be created. Now the formula of cached objects = #threads * cache size holds. APAR PK09021 is associated with SERVICE LEVEL W502032 of WebSphere Application Server V5.0 for z/OS.Temporary fix Comments
APAR is sysrouted FROM one or more of the following: PK06649 APAR is sysrouted TO one or more of the following: Modules/Macros
Publications Referenced
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Document Information |
Current web document: swg1PK09021.html
Product categories: Software > Application Servers >
Distributed Application & Web Servers > WebSphere Application
Server for z/OS
Operating system(s):
Software version: 500
Software edition:
Reference #: PK09021
IBM Group: Software Group
Modified date: Feb 26, 2006
(C) Copyright IBM Corporation 2000, 2009. All Rights Reserved.