PM20492: RECENTLY ADDED CACHE ENTRIES ARE EVICTED FROM THE CACHE BEFORE OLDER ENTRIES

Fixes are available

APAR status

Closed as program error.

Error description

After the restart of an application server in the cluster the
remaining application servers experience performance issues and
recently added cache entries are selected for eviction.

Local fix

Problem summary

****************************************************************
* USERS AFFECTED:  All users of IBM WebSphere Application      *
*                  Server V6.1 and V7.0 using cache            *
*                  replication and restarting one application  *
*                  server cluster member or servant.           *
****************************************************************
* PROBLEM DESCRIPTION: Recently added cache entries are        *
*                      evicted from the cache by the least     *
*                      recently used (LRU) algorithm.          *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
During the bootstrap process when a new application server (or
servant) joins or rejoins the replication domain each cache
entry is analyzed to determine if it should be replicated.
During this process a flag is set to indicate the cache entry
is in use.  When the cache entry is not shared the flag is not
reset.  This results in those cache entries never being
eligible for LRU eviction.  As a result, only the newly added
cache entries are eligible and are evicted.

Problem conclusion

The caching bootstrap process has been modified to set the
cache entry as not being in use so it can be eligible for LRU
eviction.

The fix for this APAR is currently targeted for inclusion in
fix packs 6.1.0.35 and 7.0.0.15.  Please refer to the
Recommended Updatespage for delivery information:
http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980

Temporary fix

Comments

APAR Information

APAR number
PM20492
Reported component name
WEBS APP SERV N
Reported component ID
5724H8800
Reported release
61A
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2010-08-13
Closed date
2010-08-27
Last modified date
2010-08-27

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

PM20763 PM36099

Fix information

Fixed component name
WEBS APP SERV N
Fixed component ID
5724H8800

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":"BU053","label":"Cloud & Data Platform"},"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:
24 October 2021

Tips

PM20492: RECENTLY ADDED CACHE ENTRIES ARE EVICTED FROM THE CACHE BEFORE OLDER ENTRIES

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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