PM43012: DYNAMIC CACHE HANG IN CACHEENTRY.SETVALUE COMPUTING HASHCODE

Fixes are available

APAR status

Closed as program error.

Error description

Dynacache hang in CacheEntry.setValue while computing hashcode.

Stack trace :
----------------------------------------------------------------
at java/util/AbstractMap.hashCode(AbstractMap.java:436(Compiled
Code))
at
com/ibm/ws/cache/CacheEntry.setValue(CacheEntry.java:748(Compile
d Code))
at com/ibm/ws/cache/Cache._syncSetValue(Cache.java:1178(Compiled
Code))
at
com/ibm/ws/cache/Cache.invalidateAndSet(Cache.java:1306(Compiled
Code))
at
com/ibm/ws/cache/DistributedObjectCacheAdapter.common_put(Distri
butedObjectCacheAdapter.java:991(Compiled Code))
at
com/ibm/ws/cache/DistributedMapImpl.put(DistributedMapImpl.java:
67(Compiled Code))
----------------------------------------------------------------

Local fix

```
N/A
```

Problem summary

****************************************************************
* USERS AFFECTED:  All users of IBM WebSphere Application      *
*                  Server using distributed maps with cache    *
*                  entries consisting of large Collections.    *
****************************************************************
* PROBLEM DESCRIPTION: A JVM hang can occur when putting a     *
*                      large Collection into a distributed     *
*                      map.                                    *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
The dynacache service calculates a hashcode for each object
that is put into the cache.  For a Collection, such as a
HashMap, the hashcode is the sum of the hashcodes of each
element in the Collection.  In a very large Collection this
process can be very time consuming and a hang may occur.

Problem conclusion

Dynacache does not extensively use the hashcode once it is
calculated.  It will now be calculated only if it is needed
and only if it has not been previously calculated.

The fix for this APAR is currently targeted for inclusion in
fix packs 7.0.0.21 and 8.0.0.2.  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
PM43012
Reported component name
WEBS APP SERV N
Reported component ID
5724H8800
Reported release
700
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2011-07-05
Closed date
2011-07-20
Last modified date
2011-11-15

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
WEBS APP SERV N
Fixed component ID
5724H8800

Applicable component levels

R700 PSY
UP
R800 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":"7.0","Line of Business":{"code":"LOB45","label":"Automation"}}]

Document Information

Modified date:
27 October 2021

Tips

PM43012: DYNAMIC CACHE HANG IN CACHEENTRY.SETVALUE COMPUTING HASHCODE

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

R700 PSY

R800 PSY

Document Information

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