This worked, but EJBTimerSerivce try look up DataSource with null:
Do you need the EJB2.x timer service? If not, you can just remove it:
thanks jaikiran for suggestion. I already tried that and its work. Howerver I am not completely sure if I can safely get rid of EJBTimers.
Reason for my post was, that I am not sure how to use c3p0 as only provider of the db connection and if this is even possible.