1:06 p.m.
Mark Egan [https://community.jboss.org/people/xmrk] created the discussion
"jBPM session persistence - "Removing a detached instance" encountered
under load / concurrency"
To view the discussion, visit: https://community.jboss.org/message/778981#778981
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I'm encountering an exception with jbpm-persistence-jpa when performing load testing
on an application-embedded jBPM. The stack trace is:
Caused by: java.lang.IllegalArgumentException: Removing a detached instance
org.drools.persistence.info.WorkItemInfo#234
at
org.hibernate.ejb.event.EJB3DeleteEventListener.performDetachedEntityDeletionCheck(EJB3DeleteEventListener.java:67)
[hibernate-entitymanager-4.0.1.Final.jar:4.0.1.Final]
at
org.hibernate.event.internal.DefaultDeleteEventListener.onDelete(DefaultDeleteEventListener.java:107)
[hibernate-core-4.0.1.Final.jar:4.0.1.Final]
at
org.hibernate.event.internal.DefaultDeleteEventListener.onDelete(DefaultDeleteEventListener.java:74)
[hibernate-core-4.0.1.Final.jar:4.0.1.Final]
at org.hibernate.internal.SessionImpl.fireDelete(SessionImpl.java:822)
[hibernate-core-4.0.1.Final.jar:4.0.1.Final]
at org.hibernate.internal.SessionImpl.delete(SessionImpl.java:801)
[hibernate-core-4.0.1.Final.jar:4.0.1.Final]
at
org.hibernate.ejb.AbstractEntityManagerImpl.remove(AbstractEntityManagerImpl.java:883)
[hibernate-entitymanager-4.0.1.Final.jar:4.0.1.Final]
at
org.drools.persistence.jpa.JpaPersistenceContext.remove(JpaPersistenceContext.java:54)
[drools-persistence-jpa-5.5.0.Final.jar:5.5.0.Final]
at
org.drools.persistence.jpa.processinstance.JPAWorkItemManager.completeWorkItem(JPAWorkItemManager.java:123)
[drools-persistence-jpa-5.5.0.Final.jar:5.5.0.Final]
I'm using 5.4.0.Final (however I observed the same behavior in 5.3.0.Final and
5.4.0.CR1). The application server is JBoss AS 7. I'm using MySQL InnoDB having
row-locking enabled.
The process calls EJBs within separate WorkItemHandlers. Here's the basic process:
1) start process,
2) call a local, no-interface EJB (injected with @Inject) and persist a domain object
(using a separate persistence context),
3) lookup another EJB (using InitialContext.doLookup) and perform some synchorous work,
4) end process.
I'm initiating the process from a REST endpoint. The jBPM session.startProcess(...)
occurs in a Local EJB exposed service.
The load test calls the REST endpoint. I'm using jMeter. The thread group only
consists of 2 threads. There is a short ramp-up.
Here's a rundown of my observations:
During ramp-up where the process service is a single thread, no issues are observed. Once
the second thread spins up, the exception is received on all subsequent calls. The
WorkItemInfo which fails to be removed is for step #2 (the local EJB call to a separate
persistence service). If I remove the third step from the definition, the issue is not
observed.
Here's my Environment for the JPAKnowledgeService.newStatefulKnowledgeSession(...).
@Produces
public Environment getEnvironment() {
Environment env = KnowledgeBaseFactory.newEnvironment();
env.set(EnvironmentName.ENTITY_MANAGER_FACTORY, emf);
env.set(EnvironmentName.TRANSACTION_MANAGER, new
ContainerManagedTransactionManager());
env.set(EnvironmentName.PERSISTENCE_CONTEXT_MANAGER, new
JpaProcessPersistenceContextManager(env));
return env;
}
I'm only using a session once and dispose of it after a single process completes.
I'm setting the following for my persistence context:
hibernate.transaction.factory_class=org.hibernate.transaction.CMTTransactionFactory
I understand that what I'm encountering could be related to general container handled
transactions across my EJB calls, but I wanted to start with the jBPM community. I had
already investigated the transaction handling on those EJB calls and wasn't able to
resolve the issue using various @TransactionAttribute or alterations to the persistence
context's properties.
I also reviewed the persistence chapter in the 5.4 User Guide:
http://docs.jboss.org/jbpm/v5.4/userguide/ch.core-persistence.html
http://docs.jboss.org/jbpm/v5.4/userguide/ch.core-persistence.html, as well as the
Multi-Threading section:
http://docs.jboss.org/jbpm/v5.4/userguide/ch.core-basics.html#d0e2358
http://docs.jboss.org/jbpm/v5.4/userguide/ch.core-basics.html#d0e2358.
Any help is appreciated.
Thanks,
-mark
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