Low concurrency using Bpm5Processor on SOA-P 5.3

Issue

We are experiencing very low performance in terms of concurrency on BPM request processing.

• When we submit more than 4 requests in the same second, we get exceptions on all requests over the fourth (only 4 complete successfully).

ERROR [org.drools.persistence.SingleSessionCommandService] (WorkManager(2)-21) Could not commit session
javax.persistence.PersistenceException: org.hibernate.exception.GenericJDBCException: could not insert: [org.drools.persistence.info.SessionInfo]
        at org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:614)
        at org.hibernate.ejb.AbstractEntityManagerImpl.persist(AbstractEntityManagerImpl.java:226)
        at org.drools.persistence.jpa.JpaPersistenceContext.persist(JpaPersistenceContext.java:24)
        at org.drools.persistence.SingleSessionCommandService.<init>(SingleSessionCommandService.java:153)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
        at java.lang.reflect.Constructor.newInstance(Unknown Source)
        at org.drools.persistence.jpa.KnowledgeStoreServiceImpl.buildCommandService(KnowledgeStoreServiceImpl.java:127)
        at org.drools.persistence.jpa.KnowledgeStoreServiceImpl.newStatefulKnowledgeSession(KnowledgeStoreServiceImpl.java:65)
        at org.drools.persistence.jpa.JPAKnowledgeService.newStatefulKnowledgeSession(JPAKnowledgeService.java:122)
        at org.jboss.soa.esb.services.jbpm5.actions.AbstractBpm5Action.getSession(AbstractBpm5Action.java:153)
        at org.jboss.soa.esb.services.jbpm5.actions.Bpm5Processor.process(Bpm5Processor.java:103)
        at org.jboss.soa.esb.listeners.message.ActionProcessingPipeline.processPipeline(ActionProcessingPipeline.java:665)
        at org.jboss.soa.esb.listeners.message.ActionProcessingPipeline.processPipeline(ActionProcessingPipeline.java:612)
        at org.jboss.soa.esb.listeners.message.ActionProcessingPipeline.process(ActionProcessingPipeline.java:442)
        at org.jboss.soa.esb.listeners.jca.JcaMessageAwareListener.process(JcaMessageAwareListener.java:163)
        at org.jboss.soa.esb.listeners.jca.JcaJMSInflowMessageProcessorAdapter.onMessage(JcaJMSInflowMessageProcessorAdapter.java:44)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)
        at org.jboss.soa.esb.listeners.jca.BaseJcaInflow$1.invoke(BaseJcaInflow.java:210)
        at org.jboss.soa.esb.listeners.jca.EndpointProxy.delivery(EndpointProxy.java:271)
        at org.jboss.soa.esb.listeners.jca.EndpointProxy.invoke(EndpointProxy.java:163)
        at $Proxy659.onMessage(Unknown Source)
        at org.jboss.resource.adapter.jms.inflow.JmsServerSession.onMessage(JmsServerSession.java:179)
        at org.jboss.jms.client.container.ClientConsumer.callOnMessageStatic(ClientConsumer.java:167)
        at org.jboss.jms.client.container.SessionAspect.handleRun(SessionAspect.java:879)
        at org.jboss.aop.advice.org.jboss.jms.client.container.SessionAspect_z_handleRun_1587407193.invoke(SessionAspect_z_handleRun_1587407193.java)
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
        at org.jboss.jms.client.container.ClosedInterceptor.invoke(ClosedInterceptor.java:172)
        at org.jboss.aop.advice.PerInstanceInterceptor.invoke(PerInstanceInterceptor.java:86)
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
        at org.jboss.jms.client.delegate.ClientSessionDelegate.run(ClientSessionDelegate.java)
        at org.jboss.jms.client.JBossSession.run(JBossSession.java:199)
        at org.jboss.resource.adapter.jms.inflow.JmsServerSession.run(JmsServerSession.java:236)
        at org.jboss.resource.work.WorkWrapper.execute(WorkWrapper.java:205)
        at org.jboss.util.threadpool.BasicTaskWrapper.run(BasicTaskWrapper.java:260)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
        at java.lang.Thread.run(Unknown Source)
Caused by: org.hibernate.exception.GenericJDBCException: could not insert: [org.drools.persistence.info.SessionInfo]
        at org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:126)
        at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:114)
        at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
        at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:64)
        at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2176)
        at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2656)
        at org.hibernate.action.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:71)
        at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:278)
        at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:320)
        at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:203)
        at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:129)
        at org.hibernate.ejb.event.EJB3PersistEventListener.saveWithGeneratedId(EJB3PersistEventListener.java:49)
        at org.hibernate.event.def.DefaultPersistEventListener.entityIsTransient(DefaultPersistEventListener.java:154)
        at org.hibernate.event.def.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:110)
        at org.hibernate.event.def.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:61)
        at org.hibernate.impl.SessionImpl.firePersist(SessionImpl.java:648)
        at org.hibernate.impl.SessionImpl.persist(SessionImpl.java:622)
        at org.hibernate.impl.SessionImpl.persist(SessionImpl.java:626)
        at org.hibernate.ejb.AbstractEntityManagerImpl.persist(AbstractEntityManagerImpl.java:220)
        ... 40 more
Caused by: java.sql.SQLException: Connection handle has been closed and is unusable
        at org.jboss.resource.adapter.jdbc.WrappedConnection.checkStatus(WrappedConnection.java:862)
        at org.jboss.resource.adapter.jdbc.WrappedConnection.checkTransaction(WrappedConnection.java:842)
        at org.jboss.resource.adapter.jdbc.WrappedStatement.checkTransaction(WrappedStatement.java:859)
        at org.jboss.resource.adapter.jdbc.WrappedPreparedStatement.executeUpdate(WrappedPreparedStatement.java:361)
        at org.hibernate.id.IdentityGenerator$GetGeneratedKeysDelegate.executeAndExtract(IdentityGenerator.java:94)
        at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:57)
        ... 55 more

The issue is easy to reproduce with maxThreads="10" (and send 10 JMS messages) for bpm5processor quickstart.

• We performed performance tests with SOA-P 5.3.0 and SOA-P 5.3.1, and noticed a significant performance degradation executing a process by multiple threads in parallel. The reason for this performance difference is the session utilization pattern. 5.3.0 uses a session-per-process-instance pattern, 5.3.1 uses a session-per-process-definition pattern, and this session is synchronized. So the benefit of using multiple threads of execution in the ESB is lost.