Hi, thanks for example.
Do you know why there is the reduncancy in classess used in persistence units, in persistence.xml? There many classes used in both persistence units. It works for me and for now, so I am happy with it, but sooner or later someone from my company will ask me "why".
Ad "Could not commit session": I had many exceptions ..., but I don't remember this one. Actually, I didn't play with the transactions yet.