APAR status
Closed as program error.
Error description
problem summary: excessive garbage collection and possibility
for out of memory error
details: cache should pool large objects (6x 10M) that are
allocated for managing disk cache.These objects are released and
reallocated when the cache is cleared. Allocating 10M objects
after the server has been running for long timmight be a strain
on garbage collection.
And if GC cannot defragment memory for this large allocation
when the cache is cleared, it might result in disabling disk
cache.
Local fix
no local fix available
Problem summary
****************************************************************
* USERS AFFECTED: All WebSphere Application Server Users *
* using Dynamic Cache and the disk *
* offload function. *
****************************************************************
* PROBLEM DESCRIPTION: Improve Dynamic Cache disk offload *
* JVM memory utilization to prevent *
* potential JVM memory fragmentation. *
****************************************************************
* RECOMMENDATION: *
****************************************************************
JVM memory fragmentation leading to possible JVM
out-of-memory exceptions or high GC activity.
Problem conclusion
During high disk offload
demand, the high rate
of allocation / deallocation of resources might
cause the JVM heap to become unusally
fragmented.
The high allocation / deallocation rate could also
overwhelm the JVM GC handler.
In rare cases, this could result in a permanent
memory allocation failure.
This APAR will do the following:
- Reduce the JVM memory requirements for
the disk offload function.
- Reduce the JVM memory allocation / deallocation
cycles from the disk offload classes.
- Reduces disk offload initial file system
requirements by 80%.
---------
Important
---------
This APAR changes the disk offload
file format. You must manually delete
the disk offload files from your
system. The default location
for these files is:
[install_root]/AppServer/temp
/[node_name]/[server_name]/_dynacache
You must delete all files and
sub-directories under the _dynacache
directory.
Temporary fix Comments
APAR information |
APAR number |
PQ98295 |
Reported component name |
WAS NETWRK DEPL |
Reported component ID |
5630A3601 |
Reported release |
00S |
Status |
CLOSED PER |
PE |
NoPE |
HIPER |
NoHIPER |
Special Attention |
NoSpecatt |
Submitted date |
2004-12-10 |
Closed date |
2004-12-22 |
Last modified date |
2004-12-22 |
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Modules/Macros
Publications Referenced
Applicable component levels |
R00A PSY |
UP |
R00H PSY |
UP |
R00I PSY |
UP |
R00P PSY |
UP |
R00S PSY |
UP |
R00W PSY |
UP |
|