I do not use pessimistic locking because it is necassary to synchronize against the parent parent parent.... process instance because a signal anywhere in the process can cause data changes up in the hierachy. So I would have to make a loadInstanceForUpdate on the parent instance. Using pessimitic locking on the row level causes deadlock situations in the database where orcale throws exceptions then. I decided to do it with a jboss cache so that i can relase the jbpmcontext during the wait for the lock in order not to hold the the database resources during waiting. But the loadInstnaceForUpdate would definitly be an option I think. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4208880#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...