Observed this on Drools 5.1.1 final when fireUntilHalt() is used. The issue is reported as 'Resolved' in post: "https://issues.jboss.org/browse/JBRULES-2756" in Drools 5.2.0 M1. So tried the same on Drools 5.2.0 final & 5.2.0 M1. Also when I try to make the recommended code changes in drools-core in Jira-2756, the issue seems to me as not fixed. In all these cases, the system consumes 100% resources of one CPU core. Please let me know does this issue is resolved or not in the latter versions of Drools? -Prashant Badhe -- View this message in context: http://drools.46999.n3.nabble.com/fireUntilHalt-is-doing-busy-wait-and-co... Sent from the Drools: User forum mailing list archive at Nabble.com.