PQ66175: EXTENSIVE GARBAGE COLLECTION OCCURING WITH MARK STACK OVERFLOW

 A fix is available

4.0.5: WebSphere Application Server Version 4.0 Fix Pack 5 (Version 4.0.5)



APAR status
Closed as program error.

Error description
Extended GC times associated with "mark stack overflow".
Heap- roots analysis shows large trees associated with com/ibm/s
ervlet/util/SimpleHashtable (WebSphere).
Local fix Problem summary
****************************************************************
* USERS AFFECTED: WebSphere Application Server installations   *
*                 experiencing large Garbage Collections.      *
****************************************************************
* PROBLEM DESCRIPTION: Extended Garbage Collections (GC)       *
*                      associated with Mark Stack overflow.    *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
Extended Garbage Collection times associated with Mark Stack
Overflow are being executed due to an imbalanced Hashtable
object.  When the hashtable was reaching its peak capacity
and required resizing, the hashtable was not being rehashed
to properly take advantage of this increased capacity.  The
lack of rehashing caused poor performance relating to seek
times for objects in the hashtable.
Problem conclusion
Modified the WebSphere internal Hashtable implementation
to properly rehash when the hashtable is expanded.
Temporary fix Comments
APAR information
APAR number PQ66175
Reported component name WEBSPHERE AE AI
Reported component ID 5630A2200
Reported release 400
Status CLOSED PER
PE NoPE
HIPER NoHIPER
Submitted date 2002-09-13
Closed date 2002-09-13
Last modified date 2002-09-13

APAR is sysrouted FROM one or more of the following:
PQ66150

APAR is sysrouted TO one or more of the following:

Modules/Macros
ENGINE          

SRLS

Fix information
Fixed component name WEBSPHERE AE AI
Fixed component ID 5630A2200

Applicable component levels
R400 PSY    UP


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > General
Operating system(s):
Software version: 400
Software edition:
Reference #: PQ66175
IBM Group: Software Group
Modified date: Sep 13, 2002