Re: [rules-users] Request for assistance in removing eval from a rule

Edson - Thank you very much for the reply. I have one more question. In the example below I changed RulesUtil to be a global name 'ruleUtil' (since its member variables do not change), and reran the rule (with the 'ruleUtil:RulesUtil()' line omitted). When I do this, and execute the rule below, I get a null pointer exception on PredicateConstraint. The first and last parts of the stack trace are: org.drools.RuntimeDroolsException: Exception executing predicate com.bah.aims.rules.Rule_my_rule_0ReturnValue0Invoker@36289b82 at org.drools.rule.PredicateConstraint.isAllowed(PredicateConstraint.java:216) at org.drools.reteoo.AlphaNode.assertObject(AlphaNode.java:132) at org.drools.reteoo.CompositeObjectSinkAdapter.propagateAssertObject(CompositeObjectSinkAdapter.java:318) at org.drools.reteoo.AlphaNode.assertObject(AlphaNode.java:140) at org.drools.reteoo.CompositeObjectSinkAdapter.propagateAssertObject(CompositeObjectSinkAdapter.java:299) at org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:153) ... Caused by: java.lang.NullPointerException at com.bah.aims.rules.Rule_my_rule__0.returnValue0(Rule_my_rule_0.java:27) at com.bah.aims.rules.Rule_my_rule_0ReturnValue0Invoker.evaluate(Rule_myRule_0ReturnValue0Invoker.java:21) at org.drools.rule.PredicateConstraint.isAllowed(PredicateConstraint.java:210) ... 29 more I'm not sure what is causing this. Any thoughts? If it helps, RulesUtil.containsKeywordString() checks to see if a string passed in is present in a list of keywords held in the class. Thanks - David ------------------------------ *From:* rules-users-bounces(a)lists.jboss.org [mailto: rules-users-bounces(a)lists.jboss.org] *On Behalf Of *Edson Tirelli *Sent:* Tuesday, September 16, 2008 9:56 AM *To:* Rules Users List *Subject:* Re: [rules-users] Request for assistance in removing eval from a rule David, Eval is really bad for perf, but still, sometimes it is the only way to do things like call methods. So, in your case, it all depends on what "containsKeywordString()" method is doing? Also, is RulesUtil just a utility class? I mean with no data you reason over? if so, I strongly advise you to make it a global, instead of matching it in the rule like a fact. Regarding evals, inline evals are just a bit lighter than top level evals, but there is an important difference: * inline evals MUST be time consistent, i.e., they must evaluate to the same value everytime they are called. * top level evals can deal with changes appropriately []s Edson 2008/9/15 Warren, David [USA] <warren_david(a)bah.com&gt; > Folks - > > After seeing the thread on evals hurting performance a couple of weeks > ago, I tried to remove them from a rule set we are using (running Drools > 4.0.4), and have had limited success. > > An example is shown below. We're using evals every time we make a call to > "rulesUtil", a helper class we have for checking strings for keywords. Two > questions: > > 1. Does using inline evals (like below) hurt performance as much as using > non-inline evals? > 2. If so, any thoughts for how to rewrite this rule to avoid using the > eval? > > > rule > 'my rule' > *salience* 790 > *activation-group* "priorityRule" > *when* > ruleUtil : RulesUtil( ) > s1 : Sensor( source == "X, $rfp : RFP , *eval*( > ruleUtil.containsKeywordString($rfp, "Y" )) , $tcn : TCN) > s2 : Sensor( TCN != $tcn, source == "Z" > *then* > System.out.println("my rule"); > priority.setPriorityName("A"); > > end > > Thanks, > David Warren > > ------------------------------ > *From:* rules-users-bounces(a)lists.jboss.org [mailto: > rules-users-bounces(a)lists.jboss.org] *On Behalf Of *Edson Tirelli > *Sent:* Friday, September 05, 2008 2:59 PM > *To:* Rules Users List > *Subject:* Re: [rules-users] Drools, Performance issues on 4.0.7 Vs 2.5 > > > Start by eliminating the evals and writing your constraints properly > inside the patterns. Drools 3+ is orders of magnitude faster than Drools > 2.x, but you need to leverage its power in your rules. Please read the > manual as the version 3 was a completely rewrite of version 2. Version 4 is > an improvement over 3. > > As an example, look at this: > http://blog.athico.com/2006/11/rush-hour-and-content-based-routing.html > > []s > Edson > > 2008/9/5 Rout, Sushanta (ThoughtMill) <Sushanta.Rout(a)ihg.com&gt; > >> We were using Drools 2.5 version earlier. Now we have switched to drools >> 4.0.7. But we see significant issues with performance like drools 4.0.7 >> is three times slower than 2.5 . Has anybody encountered the issue? >> >> Here is a sample of the rule, we have some more similar to this. >> rule "test" >> dialect "java" >> activation-group "group1" >> when >> $croNumberDetailsRequest : CRONumberDetailsRequest() >> $resdirectPhoneNumber : ResdirectPhoneNumber() >> eval($resdirectPhoneNumber.getType().getId() == 5 && >> >> $resdirectPhoneNumber.isValidForBrand($croNumberDetailsRequest.getBrand( >> )) && >> $croNumberDetailsRequest.getRegion() != null && >> >> $resdirectPhoneNumber.isValidRegion($croNumberDetailsRequest.getRegion() >> ) && >> $croNumberDetailsRequest.getLocale() != null && >> >> >> $resdirectPhoneNumber.isValidForLocaleId($croNumberDetailsRequest.getLoc >> ale()) && >> >> $resdirectPhoneNumber.isValidSlot($croNumberDetailsRequest.getSlot())); >> >> then >> ResultList.add($resdirectPhoneNumber); >> end >> >> _______________________________________________ >> rules-users mailing list >> rules-users(a)lists.jboss.org >> https://lists.jboss.org/mailman/listinfo/rules-users >> > > > > -- > Edson Tirelli > JBoss Drools Core Development > JBoss, a division of Red Hat @ www.jboss.com > > _______________________________________________ > rules-users mailing list > rules-users(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users > > -- Edson Tirelli JBoss Drools Core Development JBoss, a division of Red Hat @ www.jboss.com _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users