PM02318: IFINITE LOOP DURING APPLICATION STARTUP WHILE ACCESSING APPLICATION BINDINGS AND EXTENSION METADATA

Fixes are available

APAR status

Closed as program error.

Error description

When trying to start the appServer, clients may experience a
hang during startup at HashMap.findNonNullKeyEntry().

"server.startup : 0" TID:0x00000000312F2C00,
j9thread_t:0x000000011A2E7B20, state:CW, prio=5
(native thread ID:0x29B037, native priority:0x5, native ...
at
java/util/HashMap.findNonNullKeyEntry(HashMap.java:521(Compiled
at java/util/HashMap.getEntry(HashMap.java:506(Compiled Code))
at java/util/HashMap.get(HashMap.java:492(Compiled Code))
at org/eclipse/emf/ecore/util/BasicExtendedMetaData
.getExtendedMetaData(BasicExtendedMet
at org/eclipse/emf/ecore/util/BasicExtendedMetaData
.getName(BasicExtendedMetaData.java:3
at org/eclipse/emf/ecore/util/
BasicExtendedMetaData$EPackageExtendedMetaDataImpl.getType
at org/eclipse/emf/ecore/util/BasicExtendedMetaData
.getType(BasicExtendedMetaData.java:1
at org/eclipse/emf/ecore/xmi/impl/XMLHelperImpl
.getType(XMLHelperImpl.java:812)
... more

Note that the HashMap implementation is not synchronized.  That
is, synchronous updates to the map are unsafe and must be
avoided.  That means adding synchronization in the caller.

HashMap and the EMF code cannot be updated.  The calls through
BaseSAXXMLHandler through XMLHandler and XMLHelperImpl are
points where synchronization may be added.

BaseExtendedMetaData extends
org.eclipse.emf.ecore.util.BasicExtendedMetaData, and the
problem is with the coding of
BasicExtendedMetaData.getExtendedMetaData", which will does both
'get'and 'put' on a cache of extended metadata.  This provides a
common code point for synchronization, which is to override
'getExtendedMetaData' in the IBM extension.

There are currently no updates for 'BaseExtendMetaData' in the
WebSphere Application Server v7.0 release.

Local fix

```
N/A
```

Problem summary

****************************************************************
* USERS AFFECTED:  All users of IBM WebSphere Application      *
*                  Server V7.0                                 *
****************************************************************
* PROBLEM DESCRIPTION: During server startup, a hang may occur *
*                      in HashMap.findNonNullKeyEntry,         *
*                      from                                    *
*                      BasicExtendedMetaData.getExtendedMetadata
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
During server startup, a hang may occur in
HashMap.findNonNullKeyEntry,
from BasicExtendedMetaData.getExtendedMetadata.

The symptom will be a showing of HashMap.findNonNullKeyEntry and
BasicExtendedMetaData.getExtendedMetadata from thread dumps, for
example:

"server.startup : 0" TID:0x00000000312F2C00,
j9thread_t:0x000000011A2E7B20, state:CW, prio=5
(native thread ID:0x29B037, native priority:0x5, native ...
at java/util/HashMap.findNonNullKeyEntry(HashMap.java:521(Compil
at java/util/HashMap.getEntry(HashMap.java:506(Compiled Code))
at java/util/HashMap.get(HashMap.java:492(Compiled Code))
at
org/eclipse/emf/ecore/util/BasicExtendedMetaData.getExtendedMeta
at
org/eclipse/emf/ecore/util/BasicExtendedMetaData.getName(BasicEx
at
org/eclipse/emf/ecore/util/BasicExtendedMetaData$EPackageExtende
at
org/eclipse/emf/ecore/util/BasicExtendedMetaData.getType(BasicEx
at
org/eclipse/emf/ecore/xmi/impl/XMLHelperImpl.getType(XMLHelperIm
... more

Problem conclusion

The problem occurs because of unsynchronized access to
Eclips eMetadata Framework (EMF) metadata, where the metadata
data objects perform deferred initialization of internal data
structures.

A fix is provided as a code update which adds synchronization
to BasicExtendedMetadata.

The fix for this APAR is currently targeted for inclusion in
fix pack 7.0.0.11.  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
PM02318
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
2009-11-30
Closed date
2010-02-24
Last modified date
2010-02-24

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

[{"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"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:
24 October 2021

Tips

PM02318: IFINITE LOOP DURING APPLICATION STARTUP WHILE ACCESSING APPLICATION BINDINGS AND EXTENSION METADATA

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

Document Information

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