Re: [rules-users] Drools Flow :Persistence Problem : Restore StatefulKnowledgeSession from database

You have to load the same 'StatefulKnowledgeSession' in which you have inserted your objects. The inserted objects are serialized and stored in the column "rules_byte_array" of the session_info table. So you have to load the same session - to get to your inserted objects. There is a difference the way process map objects are handled - such as Map<String, Object> parameters = new HashMap<String, Object>(); parameters.put("x", "hello"); parameters.put("y", "hey I am y"); ksession.startProcess( "myprocess", parameters ); In the above case the parameters are not stored as part of the "session info" table. These are stored separately like in "process instance info" table + (some/other tables if you use variable persistence strategy)- so if you don't have the rules which are based on the objects you are inserting - you can get the same done through process parameters in which case you can get hold of the process instance through any new session or the same session and then its parameters. Vijay ________________________________ From: Pardeep.Ruhil(a)lntinfotech.com [mailto:Pardeep.Ruhil@lntinfotech.com] Sent: Wednesday, November 18, 2009 12:38 AM To: rules-users(a)lists.jboss.org Cc: kris.verlaenen(a)cs.kuleuven.be; Vijay K Pandey Subject: Re: [rules-users] Drools Flow :Persistence Problem : Restore StatefulKnowledgeSession from database Hi Kris, Thanks for you valuable input and Vijay of course clearing some of my doubts by asking question on this. Much of my doubt are clear except one. When we are reloading the StatefulKnowledgeSession from the database using the below line StatefulKnowledgeSession loadSession= JPAKnowledgeService.loadStatefulKnowledgeSession(id, kbase, null, env); This session object is different from the one that is created when we first created StatefulknowledgeSession object using StatefulKnowledgeSession initialSession= JPAKnowledgeService.newStatefulKnowledgeSession(kbase, null, env); Am I right ? Now In my case I have a HumanWorkItemHandler class for handling the humantask and there is ActionWorkITemHandler for my customAction workItem, which both are initailsed with the initialSession object. Now when I load the session from the database to complete the HumanWorkItemHandler task I got a different session object i.e. loadSession. Now when I insert something in the loadsession using loadSession.insert(request); So that I can use the same in ActionWorkItemHandler to exceute the action for the request. I am not able to retrieve the same request object i.e. (HttpServletRequest) from the session in ActionWorkItemHandler as when i do Collection obj = loadSession.getObject(); I get request as null. Because this loadSession is different from the one I have inserted. Kindly help in this, or I have misunderstood the concept. Thanks & Regards Pardeep Ruhil Kris Verlaenen <kris.verlaenen(a)cs.kuleuven.be&gt; 11/17/2009 04:17 PM To Rules Users List <rules-users(a)lists.jboss.org&gt;, Vijay K Pandey <VPandey(a)mdes.ms.gov&gt; cc &quot;Pardeep.Ruhil(a)lntinfotech.com&quot; <Pardeep.Ruhil(a)lntinfotech.com&gt; Subject Re: [rules-users] Drools Flow :Persistence Problem : Restore StatefulKnowledgeSession from database Preferably you should cache the session itself as well (so you don't have to recreate it all the time) and reuse that across you application. Or you could have multiple independent sessions as well. If you store the key of the session somewhere, you can easily restore this session (or sessions) after failure. Kris Quoting Vijay K Pandey <VPandey(a)mdes.ms.gov&gt;: Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm ______________________________________________________________________ ______________________________________________________________________