PQ71950,5.0: Memory leak in WAS.FFDC component
 Downloadable files
 
Abstract
Java.lang.OutOfMemory error caused by memory leak in FFDC component. From heapdump analysis most of the memory will be in:
com/ibm/ws/ffdc/IntrospectionLevelMember
 
Download Description
USERS AFFECTED: The APAR applies to WebSphere® Application Server Base environments at versions 5.0.0 and 5.0.1.

PROBLEM DESCRIPTION: A large amount of memory may be consumed and a request may appear to hang for many minutes when certain exceptions are caught by the WebSphere Application Server runtime.

RECOMMENDATION: The system is likely experiencing this problem if the following
conditions exist:
1. The system appears to have stopped processing a request (no response is seen at the browser)
2. The system does not hang on subsequent invocations of the same request after the first request has returned

This problem occurs when the FFDC engine attempts to introspect classes with a large number of fields. Since the FFDC introspection algorithm may introspect multiple levels
into an object, some classes may be deemed to have thousands, or even millions of fields (eg. a class which has 1000 fields each with the same type as the class itself would have
1000 * 1000 * 1000 = 1 000 000 000 fields after 3 levels of introspection). To test for this problem, isolate the URL that causes the hang. Be sure that this can be repeated as
the first request to the application server after server startup as FFDC caches the results of previous executions. After isolating the URL, turn off FFDC and repeat. If the hang does not occur, you very likely should apply this fix.

PROBLEM CONCLUSION: Code was modified to limit the number of fields which the FFDC engine would process in any object. If an object contains 25 or more fields, the FFDC engine will not dump it's contents.
 
Prerequisites
Install/swg24001908.html
 
 
Installation Instructions
Please view the readme file for detailed instructions
 
URL LANGUAGE SIZE(Bytes)
Readme US English 3471
 
Download package
What is DD?
Download RELEASE DATE LANGUAGE SIZE(Bytes) Download Options
PQ71950 4/2/2003 US English 8209 FTP DD
 
Technical support
1-800-IBM-SERV (U.S. calls only)
 
Cross Reference information
Segment Product Component Platform Version Edition
Application Servers Runtimes for Java Technology Java SDK
Problems (APARS) fixed
PQ71950
 
 


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server
Operating system(s): Windows
Software version: 5.0.1
Software edition:
Reference #: 4004567
IBM Group: Software Group
Modified date: Apr 11, 2003