Hi, I am working on rule and found that it is very easy to cause endless loop. For example: Rule 1 match status and update message. Rule 2 match type and update message. This will cause endless loop even I add "no-loop" on each rule. Is there anyway to avoid this? for example: each rule only execute one time, or set a maximum execute times. rule "rule 1" no-loop        when                m : Message( status == Message.HELLO)        then                System.out.println( "rule 1" );                m.setMessage( "update 1" );                update( m ); end rule "rule 2" no-loop        when                m:Message( type=="type1" )        then                System.out.println( "rule 2" );                m.setMessage( "update 2" );                update( m ); end -- View this message in context: http://drools-java-rules-engine.46999.n3.nabble.com/endless-loop-even-wit... 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

Hi. I like to add negated attributes in the condition, or other attributes that better describe the object state, like below. If you write two rules to the same object state, you should think to join the rules into one rule. rule when $object:Type(attribute=="value", secondAttribute == false, thirdAttribute == "") then // do consequence end Regards, Anderson 2011/3/23 Gabor Szokoli <szocske(a)gmail.com&gt; > This is I think something all of us came across while learning Drools... > > So I searched for "drools loop faq" in google but nothing useful came up. > I propose to extend the "inifinite recursion" section in the faq with > the best practices for avoiding this! > > My favorite way to avoid unnecessary activations is to include the > consequence among the conditions, negated: > > rule > when > $object:Type(attribute!="value") > then > modify ($object) { setAttribute("value")} > end > > > Gabor > > On Wed, Mar 23, 2011 at 12:30 PM, James Gu <jxgu(a)cnsh.delphi-tech.com&gt; > wrote: > > Hi, I am working on rule and found that it is very easy to cause endless > > loop. > > > > For example: > > Rule 1 match status and update message. > > Rule 2 match type and update message. > > This will cause endless loop even I add "no-loop" on each rule. Is there > > anyway to avoid this? for example: each rule only execute one time, or > set a > > maximum execute times. > > > > > > rule "rule 1" > > no-loop > > when > > m : Message( status == Message.HELLO) > > then > > System.out.println( "rule 1" ); > > m.setMessage( "update 1" ); > > update( m ); > > > > end > > > > rule "rule 2" > > no-loop > > when > > m:Message( type=="type1" ) > > then > > System.out.println( "rule 2" ); > > m.setMessage( "update 2" ); > > update( m ); > > end > > > > -- > > View this message in context: > http://drools-java-rules-engine.46999.n3.nabble.com/endless-loop-even-wit... > > 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 > > > > _______________________________________________ > rules-users mailing list > rules-users(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users > _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users

I tried lock-on-active and it is better than no-loop because it can avoid activate other rules in a group. Maybe it is too strong for me. What I want is : rule 1 change a attribute and it tells other rules (for example, rule 2) that the fact data is changed. rule 2 change another attribute, but do not fire rule 1 again because it is already executed. Each rule should be fired once at most. Is there anyway to do this? -- View this message in context: http://drools-java-rules-engine.46999.n3.nabble.com/endless-loop-even-wit... 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