Hi, I am a total newb to Drools and am still trying to get a clear picture of how things work. I have the HelloWorld example running in Eclipse and am trying to modify it. What I'd like to do is write a program that passes single events over a set of rules I defined in Drools. Obviously I don't know these events ahead of time and I don't know when they will be reported. Another important point is that I want each of these calls to be a stateful transaction, for example: 1) Some event type A happens and is passed through drools: Rules say to ignore the event 2) Some time later, and event type B happens and is passed through drools: Rules say to ignore the event 3) Then, some time later, another event type A happens and is passed through drools: This time the rule says to do some action because both event B AND event A occurred. (NOTE: Here, Drools would need to realize that event B has already occurred and needs to take this into account when it invokes the rules. Thus state needs to be taken into consideration.) I have been reading the documentation and have seen the stateless and stateful sessions in the javadocs. But, I'm not sure if this is what I need to accomplish the job. I was discouraged when I found this post: http://lists.jboss.org/pipermail/rules-users/2008-February/004688.html mentioning that the difference between stateful and stateless was the number of objects that could be inserted into working memory before calling fileAllRules(). >From the examples I've seen, Drools seems to be a simple program you call once and the process is terminated (as opposed to a daemon-like program that is continuously running). (Please correct me if I'm wrong.) Further, I understand that Working Memory is where all the facts in Drools are contained. I am wondering if these "facts" all disappear once an invocation of Drools has finished. Or, do stateful sessions somehow maintain state (facts) across Drools invocations? My best guess is that the Working Memory gets destroyed along with the facts after an invocation of Drools and that to achieve the state that I want, I will need to create some sort of infinite loop to encapsulate an invocation of Drools to keep all the facts in Working Memory. Is that true? I am more than happy to look all of this up myself but need a push in the right direction. (Up to this point, I've been looking mainly looking at the "JBoss Rules User Guide" and searching on the web.) Thanks for your help and I would be more that happy to clarify any points. -- View this message in context: http://www.nabble.com/Maintaining-state-across-invocations-tp22068357p220... Sent from the drools - user mailing list archive at Nabble.com. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users