PK82153: POOL SIZE GOING TO ZERO "0" OR NEGATIVE WHILE DECREMENTING THE COUNTER INCORRECTLY.

Fixes are available

APAR status

Closed as program error.

Error description

In WebSphere Application Server V6.1.0.13 where are instances
when the Java 2 Connector (J2C) component calls back the
Performance Monitoring Infrastructure (PMI) interface
incorrectly. Due to this error, the freePoolSize counter is
being decremented more times than it actually should thus
indicating wrong pool size. As this continues, the
freePoolSize value drops to and below 0. The problem was seen
in V6.1.0.21 as well after the customer upgraded to the latest
level.

Local fix

```
n/a
```

Problem summary

****************************************************************
* USERS AFFECTED:  All users of IBM WebSphere Application      *
*                  Server V6.1 and V7.0                        *
****************************************************************
* PROBLEM DESCRIPTION: At times, the DataSource Performance    *
*                      Monitoring Infrastructure (PMI)         *
*                      counter 'freePoolSize' is going         *
*                      negative.                               *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
The PMI counter freePoolSize is decremented when a connection
is allocated from the free pool or when a connection is
destroyed from the pool. It is incremented when a connection is
released to the free pool. Currently, the J2C code accounts
for these scenarios. However, there exists another scenario
where a connection is allocated and is held for a time that is
greater than the connection time out or aged timeout period.
In that case, the connection is destroyed before it is
released to the pool. Therefore, the freePoolSize is getting
decremented twice in its life cycle, both during allocation and
during destroy. This phenomenon eventually causes the
freePoolSize to be negative.

Problem conclusion

This APAR ensures the the freepoolsize value is updated
correctly in all the scenarios explained above.

The fix for this APAR is currently targeted for inclusion in
fix packs 6.1.0.27 and 7.0.0.5.  Please refer to the
Recommended Updates page for delivery information:
http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980

Temporary fix

```
ZE Fix Error, see PM09429  2010/03/19
```

Comments

APAR Information

APAR number
PK82153
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
2009-03-09
Closed date
2009-04-29
Last modified date
2010-03-19

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

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

PK82153: POOL SIZE GOING TO ZERO "0" OR NEGATIVE WHILE DECREMENTING THE COUNTER INCORRECTLY.

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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