PM77945: NEGATIVE VALUE OF ACTIVE THREAD COUNT FOR PERSISTENT DISPATCHER THREADS LEAD TO HANG.

Fixes are available

APAR status

Closed as program error.

Error description

Under very rare conditions activeThread count of
PersistentDispatcher threads can become -1. The active thread
count should be between 0 and max dispatcher threads count
which is controlled by custom property
sib.msgstore.jdbcWriteThreads (default=8)

The threaddump shows that the persistence activity waiting for
the persistent dispatcher threads dispatch to the persistence
work. This waiting for dispatch should happen only when
persistent dispacther threads are busy.

However the persistent dispatcher threads are free and are not
notified, due to -1 active thread count, that the persistent
work arrived. Persistent dispatcher threads will be waiting for
ever for the notification. This causes hang in SIB DB
persistent activity.


ReceiveListenerDispatcher thread waiting for dispatch. This
should happen only when persistent dispacther threads are busy.

3XMTHREADINFO      "JS-ReceiveListenerDispatcher : 5"
(TID:0x17535900,
sys_thread_t:0x12A4BC1C, state:CW, native ID:0x00004E08) prio=5
4XESTACKTRACE          at java/lang/Object.wait(Native Method)
4XESTACKTRACE          at java/lang/Object.wait(Object.java:199)
4XESTACKTRACE          at
com/ibm/ws/sib/msgstore/persistence/dispatcher/DispatchNotifier.
waitForD
ispatch(DispatchNotifier.java:154)
4XESTACKTRACE          at
com/ibm/ws/sib/msgstore/persistence/dispatcher/PersistentDispatc
her.disp
atch(PersistentDispatcher.java:389(Compiled Code))
4XESTACKTRACE          at
com/ibm/ws/sib/msgstore/persistence/impl/PersistentMessageStoreI
mpl.comm
it(PersistentMessageStoreImpl.java:958(Compiled Code))


However in this case all the persistent dispatcher threads are
free and waiting for the work notification.


3XMTHREADINFO      "sib.PersistentDispatcher-0" (TID:0x1B2E9900,
sys_thread_t:0x129711EC, state:CW, native ID:0x000024A4) prio=5
4XESTACKTRACE          at java/lang/Object.wait(Native Method)
4XESTACKTRACE          at
java/lang/Object.wait(Object.java:231(Compiled
Code))
4XESTACKTRACE          at
com/ibm/ws/sib/msgstore/persistence/dispatcher/PersistentDispatc
her$Pers
istentDispatcherThread.run(PersistentDispatcher.java:794)

Local fix

```
no
```

Problem summary

****************************************************************
* USERS AFFECTED:  Users of the default messaging provider     *
*                  for IBM WebSphere Application Server        *
*                  versions 6.1, 7.0, 8.0 and 8.5.             *
****************************************************************
* PROBLEM DESCRIPTION: Messaging Engine unable to dispatch     *
*                      persistent activity while persistent    *
*                      dispatcher threads are available.       *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
Under very rare conditions active thread count of Messaging
Engine's PersistentDispatcher threads can become -1.
This causes the Messaging Engine to be unable to dispatch
persistent activity like message add or delete from the
datastore even if the dispatcher threads are free to accept
persistent work.

Problem conclusion

The problem is resolved by fixing the code to gaurd the active
thread count from dropping below zero.

The fix for this APAR is currently targeted for inclusion in
fix packs 6.1.0.47, 7.0.0.29, 8.0.0.7 and the fix pack
following 8.5.0.2.  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
PM77945
Reported component name
WAS SIB & SIBWS
Reported component ID
620800101
Reported release
300
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2012-11-28
Closed date
2013-02-26
Last modified date
2013-05-25

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

PM79736

Fix information

Fixed component name
WAS SIB & SIBWS
Fixed component ID
620800101

Applicable component levels

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:
29 October 2021

Tips

PM77945: NEGATIVE VALUE OF ACTIVE THREAD COUNT FOR PERSISTENT DISPATCHER THREADS LEAD TO HANG.

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

R800 PSY

Document Information

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