Unexpected error occurred :concurrent access to HashMap attempted

Question

While runnig the ALBPM 5.7 we got this error. This looks like the ALBPM workflow engine is using HashMap in a unsynchronized way. is this a known issue and is there a work around for this?
This error happened shortly after a possible blip in the database server, with exception message which said:
Message:
The connectivity to the BEA AquaLogic™ BPM Server database has been successful restablished.
Any thoughts/insight/past experience....
Looks like we should be using Hashtable instead of a HashMap (or atleast a Synchronized HashMap)
This is best done at creation time, to prevent accidental unsynchronized access to the map:
Map m = Collections.synchronizedMap(new HashMap(...));
See Exception message below
Message:
An unexpected error occurred while running an automatic item.
Details: Connector [ffmaeng_ENGINE_DB_FUEGOLABS_ARG:SQL:Oracle (ALI)] caused an exception when getting a resource of type [0].
Detail:Connector [ffmaeng_ENGINE_DB_FUEGOLABS_ARG:SQL:Oracle (ALI)] caused an exception when getting a resource of type [0].
Caused by: concurrent access to HashMap attempted by Thread[ET(49),5,Execution Thread Pool]
fuego.connector.ConnectorException: Connector [ffmaeng_ENGINE_DB_FUEGOLABS_ARG:SQL:Oracle (ALI)] caused an exception when getting a resource of type [0].
Detail:Connector [ffmaeng_ENGINE_DB_FUEGOLABS_ARG:SQL:Oracle (ALI)] caused an exception when getting a resource of type [0].
at fuego.connector.ConnectorException.exceptionOnGetResource(ConnectorException.java:95)
at fuego.connector.ConnectorTransaction.getResource(ConnectorTransaction.java:285)
at fuego.connector.JDBCHelper.getConnection(JDBCHelper.java:43)
at fuego.server.service.EngineConnectorService.getConnection(EngineConnectorService.java:260)
at fuego.server.service.EngineConnectorService.getEngineConnection(EngineConnectorService.java:160)
at fuego.transaction.TransactionAction.getEngineHandle(TransactionAction.java:180)
at fuego.server.execution.EngineExecutionContext.getEngineHandle(EngineExecutionContext.java:352)
at fuego.server.execution.EngineExecutionContext.persistInstances(EngineExecutionContext.java:1656)
at fuego.server.execution.EngineExecutionContext.persist(EngineExecutionContext.java:1010)
at fuego.transaction.TransactionAction.beforeCompletion(TransactionAction.java:133)
at fuego.connector.ConnectorTransaction.beforeCompletion(ConnectorTransaction.java:654)
at fuego.connector.ConnectorTransaction.commit(ConnectorTransaction.java:330)
at fuego.transaction.TransactionAction.commit(TransactionAction.java:303)
at fuego.transaction.TransactionAction.startBaseTransaction(TransactionAction.java:470)
at fuego.transaction.TransactionAction.startTransaction(TransactionAction.java:540)
at fuego.transaction.TransactionAction.start(TransactionAction.java:213)
at fuego.server.execution.DefaultEngineExecution.executeImmediate(DefaultEngineExecution.java:118)
at fuego.server.execution.DefaultEngineExecution.executeAutomaticWork(DefaultEngineExecution.java:58)
at fuego.server.execution.EngineExecution.executeAutomaticWork(EngineExecution.java:42)
at fuego.server.execution.ToDoItem.executeAutomaticWork(ToDoItem.java:264)
at fuego.server.execution.ToDoItem.run(ToDoItem.java:531)
at fuego.component.ExecutionThread.processMessage(ExecutionThread.java:754)
at fuego.component.ExecutionThread.processBatch(ExecutionThread.java:734)
at fuego.component.ExecutionThread.doProcessBatch(ExecutionThread.java:140)
at fuego.component.ExecutionThread.doProcessBatch(ExecutionThread.java:132)
at fuego.fengine.ToDoQueueThread$PrincipalWrapper.processBatch(ToDoQueueThread.java:432)
at fuego.component.ExecutionThread.work(ExecutionThread.java:818)
at fuego.component.ExecutionThread.run(ExecutionThread.java:397)
Caused by: java.util.ConcurrentModificationException: concurrent access to HashMap attempted by Thread[ET(49),5,Execution Thread Pool]
at java.util.HashMap.onExit(HashMap.java:226)
at java.util.HashMap.transfer(HashMap.java:690)
at java.util.HashMap.resize(HashMap.java:676)
at java.util.HashMap.addEntry(HashMap.java:1049)
at java.util.HashMap.put(HashMap.java:561)
at fuego.lang.cache.CacheStatistic.lock(CacheStatistic.java:246)
at fuego.lang.cache.TimedMultiValuatedCache.getLocked(TimedMultiValuatedCache.java:282)
at fuego.lang.cache.TimedPool.get(TimedPool.java:80)
at fuego.connector.impl.BaseJDBCPooledConnector.getConnection(BaseJDBCPooledConnector.java:140)
at fuego.connector.impl.BaseJDBCConnector.getResource(BaseJDBCConnector.java:222)
at fuego.connector.ConnectorTransaction.getResource(ConnectorTransaction.java:280)
... 26 more

Answer 1

Hi BalusC,
I forgot to tell one thing, the exception what I mentioned is coming very rarely. The application is in Production and they getting this Exception once in 3 months. Is there any way to re-produce the same exception number of times to check whether it has been fixed or not after installing the updates as you said. If you have any information regarding this exception please send me.
Thank You.