PM56238: NULLPOINTEREXCEPTION IN OBJECTMANAGER BTREE CAN CAUSE DIFFERENT PROBLEMS

Fixes are available

APAR status

Closed as program error.

Error description

The following exception is observed:

java.lang.NullPointerException at
com.ibm.ws.objectManager.BTree$Node.get(BTree.java:722) at
com.ibm.ws.objectManager.BTree$Node.get(BTree.java:722) at
com.ibm.ws.objectManager.BTree.getEntry(BTree.java:246) at
com.ibm.ws.objectManager.SingleFileObjectStore.get(SingleFileObj
ectStore.java:440) at
..............

The stacks below these will belong to the messaging engine
(com.ibm.ws.sib...).  This NullPointerException can occur in a
variety of contexts and the consequence will depend on that
context.  The observed context was the Messaging Engine spill
dispatcher, and the consequence was that the spill dispatcher
could no longer accept work, and eventually the JVM hosting
the messaging engine was panicked.

Other symptoms could simply be a failure to perform a
messaging operation or the messaging engine fails updating
state in the filestore.

Local fix

Problem summary

****************************************************************
* USERS AFFECTED:  Users of the default messaging provider     *
*                  for                                         *
*                  IBM WebSphere Application Server            *
****************************************************************
* PROBLEM DESCRIPTION: NullPointerException in FileStore       *
*                      BTree which can have a variety of       *
*                      symptoms.                               *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
The NullPointerException occurs in the store files BTree
implementation.  This BTree is the data structure used to
provide directory services inside the store file.
Nodes in the BTree can drop out of memory if not traversed for
a period of time.  This avoids excessive heap usage when there
are many objects in the store file.
A race condition exists where a thread traverses the BTree at
the same time the CheckPointHelper thread (which can cause
nodes to drop from memory) drops a node, resulting in the
NullPointerException.

Problem conclusion

This APAR avoids the race by taking a reference to the node
before accessing its methods.

The fix for this APAR is currently targeted for inclusion in
fix pack 6.1.0.45, 7.0.0.23, and 8.0.0.4. 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
PM56238
Reported component name
PLAT MSG COM
Reported component ID
620600101
Reported release
200
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2012-01-20
Closed date
2012-03-19
Last modified date
2012-03-19

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
PLAT MSG COM
Fixed component ID
620600101

Applicable component levels

R200 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:
28 October 2021

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PM56238: NULLPOINTEREXCEPTION IN OBJECTMANAGER BTREE CAN CAUSE DIFFERENT PROBLEMS

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

R200 PSY

Document Information

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