PQ81144; 5.0.2.1: Filter chain cache leads to hashmap growth
 Downloadable files
 
Abstract
WebAppFilterManager is caching the FilterChainContents based on URI, and since each URI is unique, the HashMap of URI to FilterChainContent can grow without limit.
 
Download Description

PQ81144 resolves the following problem:

USERS AFFECTED:
WebSphere® Application Server users of WebSphere Portal Server

PROBLEM DESCRIPTION:
Filter chain cache keeps growing if all URIs are unique. It eats up memory eventually.

RECOMMENDATION:
Filter chain was implemented with hashmap. When URIs are uniquely generated like those from portal, the cache keeps growing and eventually causes OutOfMemoryException.

PROBLEM CONCLUSION:
Utilize URLCache to recycle least used entries to maintain cache size within maximum number of elements.

The maximum number is set to 500, which is big enough for most Web applications whose URIs can be determined. For applications like WebSphere Portal Server, which uses unique URIs, the cache size is considered acceptable, even though the cache itself is not useful.

Filter chain cache may lead to hashmap growth and consume memory. In cases such as WebSphere Portal Server, where all URLs are unique, the filter chain cache cannot reclaim memory used by entries, and the cache has no limitation of growth. This could eventually force the server to shutdown due to an OutOfMemoryException.

This APAR has been included in service pack 5.0.2.3.
 
Prerequisites
Please download the UpdateInstaller below to install this fix.
 
URL LANGUAGE SIZE(Bytes)
UpdateInstaller for V5.0 releases US English 7000000
 
 
Installation instructions
Please review the readme.txt for detailed installation instructions.
 
URL LANGUAGE SIZE(Bytes)
Readme US English 2015
 
Download package
What is DD?
DOWNLOAD RELEASE DATE LANGUAGE SIZE(Bytes) Download Options
PQ81144_fix_501 6/22/2004 US English 10912 FTP DD
PQ81144_fix_502 6/22/2004 US English 10912 FTP DD
 
Technical support
1-800-IBM-SERV (U.S. Only)
 
Cross Reference information
Segment Product Component Platform Version Edition
Application Servers Runtimes for Java Technology Java SDK
Problems (APARs) fixed
PQ81144
 
 


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > Servlet Engine/Web Container
Operating system(s): Windows
Software version: 5.0.2.1
Software edition:
Reference #: 4007353
IBM Group: Software Group
Modified date: Jun 30, 2004