Jason J [https://community.jboss.org/people/jasonjho] created the discussion "Multiple sessions and thread safety using jBPM persistence" To view the discussion, visit: https://community.jboss.org/message/773528#773528 -------------------------------------------------------------- For every workflow process I am creating a *new* separate kbase/ksession.   So every flow is bound to a unique session and *not* shared. I have enabled JPA persistence and pass in the following env to *each* new session: env = KnowledgeBaseFactory.newEnvironment(); env.set(EnvironmentName.ENTITY_MANAGER_FACTORY, emf); env.set(EnvironmentName.TRANSACTION_MANAGER, TransactionManagerServices.getTransactionManager()); session = createNewSession(env) session.startProcess(...) I am getting Hibernate StaleObjectExceptions and OptimisticLocking errors when I perform multiple operations on different processes. I am not sure what specific DB operation is causing this, but since each process is in its own KSession - how is this even possible? What database update could be in contention between 2 threads in this case? I am using jBPM5.2. Any ideas??? -------------------------------------------------------------- Reply to this message by going to Community [https://community.jboss.org/message/773528#773528] Start a new discussion in jBPM at Community [https://community.jboss.org/choose-container!input.jspa?contentType=1&...]