Dear all, I got the example from http://blog.athico.com/2009/09/drools-flow-variable-persistence.html http://blog.athico.com/2009/09/drools-flow-variable-persistence.html I understood the code ( as i m a fresher at drools as well as JPA it took some time) but still the code shows that how variables and state of process are persisted but i want to know in case a sever fails then how the recovery will take place.... i had an idea that the process-restart(using loadStatefulKnowledgeSession(ID)) will trigger and load all sessions present in the DB and so i tried it and restarted the session but i could not load the workitems and the variables thus got an null pointer exception the sample code uses the existing variable in code for processInstance and workItem to get their ID(xyz.getId()) which wouldnt work in case of server crash Also if There are some (e)books on drools 5.1 then please provide more info on them any help in the form of examples is very welcome thanks in advance..... -- View this message in context: http://n3.nabble.com/Drools-and-Persistence-Example-tp182637p182637.html Sent from the Drools - User mailing list archive at Nabble.com.