PK76345: Performance degradation in WebSphere Application Server Dynacache.

Fixes are available

APAR status

Closed as program error.

Error description

In certain scenarios when the cache is full (for example, if
it has reached the limit specified in terms of number of
entries) dynacache performance degrades due to a bug in the
least recently used (LRU) algorithm.

Local fix

```
No work around.
```

Problem summary

****************************************************************
* USERS AFFECTED:  All users of WebSphere Application Server   *
*                  V6.1 and V7.0 who use DynaCache servlet     *
*                  caching                                     *
****************************************************************
* PROBLEM DESCRIPTION: Performance degradation when the        *
*                      cache is full.                          *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
Performance degradation occurs during eviction of least
recently used (LRU) entries from the cache.

Problem conclusion

The implementation and performance of the DynaCache LRU
algorithm, has been  fixed to efficiently evict entries from a
full cache, when making room for new entries.

The fix for this APAR is currently targeted for inclusion in
fix packs 6.1.0.23 and 7.0.0.3.
Please refer to the Recommended Updates page for delivery
information:
http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980

Temporary fix

Comments

**** Note: the interim fix for this APAR superceds the fix for
PK67942

APAR Information

APAR number
PK76345
Reported component name
WEBSPHERE APP S
Reported component ID
5724J0800
Reported release
61A
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2008-11-24
Closed date
2008-12-09
Last modified date
2009-02-13

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

Fix information

Fixed component name
WEBSPHERE APP S
Fixed component ID
5724J0800

Applicable component levels

R61A PSY
UP
R61H PSY
UP
R61I PSY
UP
R61P PSY
UP
R61S PSY
UP
R61W PSY
UP
R61Z PSY
UP
R700 PSY
UP

[{"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SSEQTP","label":"WebSphere Application Server"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"6.1","Line of Business":{"code":"LOB45","label":"Automation"}}]

Document Information

Modified date:
29 December 2021

Tips

PK76345: Performance degradation in WebSphere Application Server Dynacache.

Fixes are available

Subscribe

APAR status

Closed as program error.

Error description

Local fix

Problem summary

Problem conclusion

Temporary fix

Comments

APAR Information

APAR number

Reported component name

Reported component ID

Reported release

Status

PE

HIPER

Special Attention

Submitted date

Closed date

Last modified date

APAR is sysrouted FROM one or more of the following:

APAR is sysrouted TO one or more of the following:

Fix information

Fixed component name

Fixed component ID

Applicable component levels

R61A PSY

R61H PSY

R61I PSY

R61P PSY

R61S PSY

R61W PSY

R61Z PSY

R700 PSY

Document Information

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