APAR status
Closed as program error.
Error description
When the application server is under heavy load on WebSphere 5.1
with memory-to-memory session clustering(client/server mode),
java.util.ConcurrentModificationException appears
intermittently in the SystemOut.log file on the DRS servers.
The installation's SystemOut.log had a couple of different
exceptions but they contained the following stack trace snippet:
DRSCacheApp E DRSW0008E: Exception is: java.util.
ConcurrentModificationException
at java.util.HashMap$HashIterator.nextEntry(HashMap.java)
at java.util.HashMap$EntryIterator.next(HashMap.java)
Local fix Problem summary
****************************************************************
* USERS AFFECTED: WebSphere Application Servers users using *
* memory to memory replication *
****************************************************************
* PROBLEM DESCRIPTION: Exception is: java.util. *
* ConcurrentModificationException *
* *
* at java.util.HashMap$HashIterator. *
* nextEntry(HashMap.java(Compiled Co *
* at java.util.HashMap$EntryIterator. *
* next(HashMap.java(Compiled Code)) *
* at java.util.HashMap.writeObject *
* (HashMap.java(Compiled Code)) *
* *
* at sun.reflect.GeneratedMethod *
* Accessor15.invoke(Unknown Source) *
* *
* at sun.reflect.DelegatingMethod *
* *
* AccessorImpl.invoke(DelegatingMethodA *
* *
* at java.lang.reflect.Method.invoke *
* (Method.java(Compiled Code)) *
* at java.io.ObjectStreamClass. *
* invokeWriteObject *
* (ObjectStreamClass.jav *
* at java.io.ObjectOutputStream. *
* *
* writeSerialData(ObjectOutputStream.jav *
* *
* at java.io.ObjectOutputStream. *
* *
* writeOrdinaryObject(ObjectOutputStream *
* *
* at java.io.ObjectOutputStream. *
* *
* writeObject0(ObjectOutputStream.java(C *
* *
* at java.io.ObjectOutputStream. *
* *
* writeObject(ObjectOutputStream.java(Co *
* *
* at com.ibm.ws.drs.DRSCacheMsg. *
* writeExternal(DRSCacheMsg.java:177) *
* *
* at java.io.ObjectOutputStream. *
* *
* writeExternalData(ObjectOutputStream.j *
* *
* at java.io.ObjectOutputStream. *
* *
* writeOrdinaryObject(ObjectOutputStream *
* *
* at java.io.ObjectOutputStream. *
* *
* writeObject0(ObjectOutputStream.java(C *
* *
* at java.io.ObjectOutputStream. *
* *
* writeObject(ObjectOutputStream.java(Co *
* *
* at com.ibm.disthub.impl.client. *
* *
* MessageImpl.setObjectBody(MessageImpl *
* *
* at com.ibm.disthub.impl.jms. *
* ObjectMessageImpl.setObject *
* (ObjectMessag *
* at com.ibm.ws.drs.DRSJMS.jmsAckGet *
* (DRSJMS.java:981) *
* at com.ibm.ws.drs.DRSCacheApp. *
* jmsAckGet(DRSCacheApp.java:3043) *
* *
* at com.ibm.ws.webcontainer.httpsession. *
* DRSHttpSessCache.getEntry(DRS *
* at com.ibm.ws.drs.DRSJMS.onMessage *
* (DRSJMS.java(Compiled Code)) *
* at com.ibm.ws.drs.DRSCacheApp. *
* onMessage(DRSCacheApp.java(Compiled *
* C *
* at com.ibm.disthub.impl.jms. *
* MessageConsumerImpl.dispatch *
* (MessageCons *
* at com.ibm.disthub.impl.jms. *
* MessageImpl.dispatch(MessageImpl.java *
* (Co *
* at com.ibm.disthub.impl.jms. *
* SessionDispatcher.run *
* (SessionDispatcher. *
****************************************************************
* RECOMMENDATION: *
****************************************************************
Replicated data should be cloned before sending over to
another node. This should address the concurrent modification
problem.
Problem conclusion
The code is fixed to address this problem.
Temporary fix
Fix uploaded to
PQ99999.
Comments
APAR information |
APAR number |
PQ87654 |
Reported component name |
WAS BASE 5.0 |
Reported component ID |
5630A3600 |
Reported release |
10A |
Status |
CLOSED PER |
PE |
NoPE |
HIPER |
NoHIPER |
Special Attention |
NoSpecatt |
Submitted date |
2004-04-16 |
Closed date |
2004-05-17 |
Last modified date |
2004-05-17 |
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Modules/Macros
Publications Referenced
Applicable component levels |
R003 PSY |
UP |
R00A PSY |
UP |
R00H PSY |
UP |
R00I PSY |
UP |
R00P PSY |
UP |
R00S PSY |
UP |
R00W PSY |
UP |
R103 PSY |
UP |
R10A PSY |
UP |
R10H PSY |
UP |
R10I PSY |
UP |
R10P PSY |
UP |
R10S PSY |
UP |
R10W PSY |
UP |
|