APAR status
Closed as program error.
Error description
In the PUSH replication mode WebSphere Application Server
Dynacache sends replication messages that are large, which
frequently
causes the Java Virtual Machines in a clustered environment to
exhaust
their heaps, resulting in Out Of Memory errors and heap dumps.
The fix allows the user to specify a few custom
properties enable Dynacache to chunk these messages
thereby sending
only a few cache entries at a time in a message, resulting in
smaller objects and helping these heap exhaustion issues.
Local fix Problem summary
****************************************************************
* USERS AFFECTED: WebSphere Application Server users of *
* dynamic cache who configure cache *
* replication in PUSH mode. *
****************************************************************
* PROBLEM DESCRIPTION: In the PUSH replication mode *
* Dynacache sends large replication *
* messages *
* which frequently cause the *
* Java Virtual Machiness in a clustered *
* environment to *
* exhaust their heaps, resulting in *
* OutOfMemory errors and heap dumps. *
****************************************************************
* RECOMMENDATION: *
****************************************************************
In the PUSH replication mode Application Server's, Dynacache
service sends replication messages that are large, which
frequently causes
the servers in a clustered
environment to exhaust their
java virtual machine heaps, resulting in OutOfMemory errors and
heap dumps. PK32201
relieves this issue by allowing the user to control
the size (in terms of number of cache entries) of the sent
messages.
Problem conclusion
The batch size of the replication data can now be configured
using the following custom properties:
com.ibm.ws.cache.CacheConfig.cachePercentageWindow: Specifies
a limit on the number of cache entries sent by the Data
Replication Service in terms of the percentage of total cache in
memory. Default value: 2% of the no. of entries in the cache
Scope: configurable per cache instance
com.ibm.ws.cache.CacheConfig.cacheEntryWindow: Specifies a
limit on the total number of cache entires sent by the Datat
Replication Service in terms of number of entries.
Default value: 50 entries
Scope: configurable per cache instance
com.ibm.ws.CacheConfig.batchUpdateMilliseconds: Specifies
a batch update frequency in terms of milliseconds. Setting
this property will result in Dynacache processing updates
more frequently, and thus reducing the payload size.
Default Value: 1000 ms (1 s)
The fix for this APAR is currently targeted for inclusion
in cumulative fix 5.1.1.14, and fixpacks 6.0.2.19, and 6.1.0.7.
Please refer to the recommended updates page for delivery
information:
http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
Temporary fix Comments
APAR information |
APAR number |
PK32201 |
Reported component name |
WEBSPHERE BASE |
Reported component ID |
5630A3600 |
Reported release |
10A |
Status |
CLOSED PER |
PE |
NoPE |
HIPER |
NoHIPER |
Special Attention |
NoSpecatt |
Submitted date |
2006-09-29 |
Closed date |
2006-11-21 |
Last modified date |
2007-04-13 |
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Modules/Macros
Publications Referenced
|
Fix information |
Fixed component name |
WEBSPHERE BASE |
Fixed component ID |
5630A3600 |
Applicable component levels |
R00A PSN |
UP |
R00H PSN |
UP |
R00P PSN |
UP |
R00S PSN |
UP |
R00W PSN |
UP |
R10A PSY |
UP |
R10H PSY |
UP |
R10P PSY |
UP |
R10S PSY |
UP |
R10W PSY |
UP |
|