-> resources: i'm sorry, i'm new to the discussion board, too. so i have no idea where to find the original discussion thread. -> exception: the exception is caught after all in org.jbpm.svc.Services in Line 226. The original Exception is caught earlier but gets wrapped into a JbpmPersistenceException and is thrown further. -> locking-mechanism: you could also use a simple process variable to indicate the locking. as kukeltje stated the problem is the failover-scenario. what happens if the server crashes and the lock stays? another approach might be to change the isolaotion-level of the database. this way you could take advantage of the existing locking-mechnism provided by your database. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4163535#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...