Hi, Following are details of our configurations for Drools: 1. Drools v 5.1.1 2. Drools statefull kSession is initialized using Spring framework 3. We are using Resource scanner through change-set.xml. Scan interval is set as 1 second. drools.Clocktype=realtime. drools.agent.newInstance=false. 4. There are about 8 DRL resources in the repository folder that resource scanner scans. 5. Each DRL file has multiple rules. Within each DRL file, I am using same aganda-group. Issue: After web server startup, it is observed that rules from some of the DRL files fires. But, rules from 1 DRL file DO NOT fire at all. There are no compilation errors/warnings appearing in log files after web server startup. If I remove this DRL file from repository (this is the location which resource scanner scans) and copy it again after say 2-3 seconds, then the rules from this file starts firing when appropriate facts are introduced in WM. Earlier I was using fireUntilHalt() to trigger rules, but now I am issuing fireAllRules(). This was changed as I observed a 100% CPU consumption issue when fireUntilHalt() even when the application is in idle state. See "http://drools.46999.n3.nabble.com/fireUntilHalt-is-doing-busy-wait-and-consuming-100-of-one-CPU-core-td3844714.html" I am using resource scanner feature to dynamically add/remove DRL files without requiring restart of web server on production servers. Does anybody faced similar issue in Drools 5.1.1 final? Does resource scanner requires re-initialization of kSession after add/update of DRL file in repository folder? Thanks in advance, Prashant Badhe -- View this message in context: http://drools.46999.n3.nabble.com/Rule-firing-issue-in-Drools-5-1-1-tp388... Sent from the Drools: User forum mailing list archive at Nabble.com.