PK71856: UNDER LOAD, NO PMI STATISTICS COLLECTED FOR A URI AND A NULLPOINTEREXCEPTION OCCURS

Fixes are available

APAR status

Closed as program error.

Error description

During a load test with Performance Monitoring Infrastructure
(PMI) statistics enabled an error occurs during registration
of URI statistics:

PmiRegistry   W   CWPMI0023W: Unable to register PMI module due
to duplicate name:  <URL string>

and this is then followed by a null pointer exception during
stop of the associated application:

[7/9/08 23:40:10:269 CDT] 00000041 ServletWrappe E   SRVE0058E:
Did not realize destroy() exception thrown by servlet
<servlet_name>
at
com.ibm.ws.webcontainer.servlet.ServletWrapper.doDestroy(Servlet
Wrapper.java:899)
at
com.ibm.ws.wswebcontainer.servlet.ServletWrapper.doDestroy(Servl
etWrapper.java:692)
at
com.ibm.ws.webcontainer.servlet.ServletWrapper.destroy(ServletWr
apper.java:966)
.
.
---- Begin backtrace for Nested Throwables
java.lang.NullPointerException
at
com.ibm.wsspi.pmi.factory.StatsFactory.removeStatsInstance(Stats
Factory.java:470)
at
com.ibm.ws.wswebcontainer.stats.UrlPmiModule.destroy(UrlPmiModul
e.java:138)
at
com.ibm.ws.wswebcontainer.stats.ServletPmiModule.destroy(Servlet
PmiModule.java:193)
at
com.ibm.ws.wswebcontainer.stats.WebAppModule.onServletUnloaded(W
ebAppModule.java:309)

Local fix

```
No workaround
```

Problem summary

****************************************************************
* USERS AFFECTED:  IBM WebSphere Application Server Version    *
*                  6.1 users of Performance Monitoring         *
*                  Infrastructure (PMI) statistics.            *
****************************************************************
* PROBLEM DESCRIPTION: If servlet statistics are enabled,      *
*                      under load the WebContainer may         *
*                      attempt to register the same URI for    *
*                      a given servlet twice. As a result,     *
*                      no statistics are collected for the     *
*                      URI and a NullPointerException occurs   *
*                      when the application is stopped.        *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
If the first two requests for a servlet use the same URI, and
are received at the same time, there is a small timing window in
which the WebContainer will attempt to register the same URI for
statistics collection twice. As a result, the second
registration fails and the WebContainer does not handle such a
failure. The problem cannot occur for subsequent requests for
the servlet.

Problem conclusion

The timing window has been closed such that the WebContainer
will no longer attempt to register the same URI for statistics
collection twice. Further, should a failure occur during URI
statistic registration, this will no longer result in the
reported NullPointerException when the application is stopped.

The fix for this APAR is currently targeted for inclusion in
fixpack 6.1.0.23.  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
PK71856
Reported component name
WEBSPHERE APP S
Reported component ID
5724J0800
Reported release
61I
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2008-09-10
Closed date
2008-09-22
Last modified date
2009-03-30

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

PK71856: UNDER LOAD, NO PMI STATISTICS COLLECTED FOR A URI AND A NULLPOINTEREXCEPTION OCCURS

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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