I have a process that uses an asyncrhonous work item handler to execute several branches in parallel. I'm using JPAWorkingMemoryDbLogger to persist the log to the database.The issue is that the commit  for the completeWorkItem invocation fails with StaleObjectException on those threads.

It seems the completeWorkItem invocations are attempting to update the org.drools.persistence.info.SessionInfo entity, and it fails because a optimistick lock exception. (That entity was modified first when the session.startProcessInstance commited to the database).

Here is the exception:

2012-08-28 15:13:20,962 [Thread-6]  DEBUG (SQLStatementLogger.java:111) - update SessionInfo set lastModificationDate=?, rulesByteArray=?, startDate=?, OPTLOCK=? where id=? and OPTLOCK=?
org.hibernate.StaleStateException: Unexpected row count: 0; expected: 1
    at org.hibernate.jdbc.Expectations$BasicExpectation.checkNonBatched(Expectations.java:102)
    at org.hibernate.jdbc.Expectations$BasicExpectation.verifyOutcome(Expectations.java:67)
    at org.hibernate.persister.entity.AbstractEntityPersister.check(AbstractEntityPersister.java:1774)
    at org.hibernate.persister.entity.AbstractEntityPersister.update(AbstractEntityPersister.java:2425)
    at org.hibernate.persister.entity.AbstractEntityPersister.updateOrInsert(AbstractEntityPersister.java:2325)
    at org.hibernate.persister.entity.AbstractEntityPersister.update(AbstractEntityPersister.java:2625)
    at org.hibernate.action.EntityUpdateAction.execute(EntityUpdateAction.java:115)
    at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:279)
    at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:263)
    at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:168)
    at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321)
    at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:50)
    at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1028)
    at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:366)
    at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:137)
    at org.hibernate.ejb.TransactionImpl.commit(TransactionImpl.java:54)
    at org.springframework.orm.jpa.JpaTransactionManager.doCommit(JpaTransactionManager.java:512)
    at org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:754)
    at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:723)
    at com.mypackage.workflow.impl.jbpm.runtime.workitemhandlers.WebServiceWorkItemHandler$1.run(WebServiceWorkItemHandler.java:178)
    at java.lang.Thread.run(Thread.java:662)
2012-08-28 16:16:21,779 [Thread-4]  ERROR (AbstractFlushingEventListener.java:324) - Could not synchronize database state with session
org.hibernate.StaleObjectStateException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect): [org.drools.persistence.info.SessionInfo#281]
    at org.hibernate.persister.entity.AbstractEntityPersister.check(AbstractEntityPersister.java:1782)
    at org.hibernate.persister.entity.AbstractEntityPersister.update(AbstractEntityPersister.java:2425)
    at org.hibernate.persister.entity.AbstractEntityPersister.updateOrInsert(AbstractEntityPersister.java:2325)
    at org.hibernate.persister.entity.AbstractEntityPersister.update(AbstractEntityPersister.java:2625)
    at org.hibernate.action.EntityUpdateAction.execute(EntityUpdateAction.java:115)
    at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:279)
    at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:263)
    at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:168)
    at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321)
    at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:50)
    at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1028)
    at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:366)
    at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:137)
    at org.hibernate.ejb.TransactionImpl.commit(TransactionImpl.java:54)
    at org.springframework.orm.jpa.JpaTransactionManager.doCommit(JpaTransactionManager.java:512)
    at org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:754)
    at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:723)
    at com.mypackage.workflow.impl.jbpm.runtime.workitemhandlers.WebServiceWorkItemHandler$1.run(WebServiceWorkItemHandler.java:178)
    at java.lang.Thread.run(Thread.java:662)

I've seen this kind of issue reported in other discussions in the forum, but at the moment I don't think an answer has been given. It seems to be an issue in the jbpm persistence engine, but I might be mistaken and I might be  doing something wrong.

So, how could I avoid these exceptions?

Thanks