1.) “It is important to place the logger before the persistence service, since it may need the Hibernate session to load some information.” –> Can you elaborate a bit why this is necessary?

When generating the events we want to include process status information. So we query jbpm objects (e.g. token.getProcessDefinition().getVersion(). Maybe the processDefinition wasn’t accessed earlier, so you need the HibernateSession to lazy load it. Okay, ProcessDefinition isn’t a good example, but I don’t remember which fields caused problems at the moment And it doesn’t matter anyway, by having the services ordered correctly, we avoid any lazy load trouble at this point.

2.) Which CEP engine/visualisation did you use?

Currently none The events are sent to a central process administration, which is self implemented (at the current stage it is basically an EJB3 SessionBean and some EJB3-Entities, accessed as I mentioned via ESB).