October 2011 - rules-users - Jboss List Archives

Fire Rule in Stateless Knowledge Session

by snehils

Hi, I am new in Drools. I am using Drools version 5.1.0 My requirement is kind of request response, where I have to perform some checks for the request and respond the result. Hence, I decided to go with stateless knowledge session. I have prepared .DRL file and it contains set of rules. When some request receives I have to identify the rule(s) belongs to that request and then fire the rule(s). I am not able to figure out how to categories the rules request wise in DRL file? Also, how to fire only those rules which belongs to the category. For example, there are three kinds of requests Rq1, Rq2 and Rq3. There are rules in DRL file: R1, R2, R3, R4 and R5. R1, R2 belongs to Rq1, R3 belongs to Rq2 and R4, R5 belongs to Rq3. When some request receives only its belonging rules should be fired. For example, on receiving of Rq2 only R3 should be fired. Please provide me some code snipped or link. Thanks -- View this message in context: http://drools.46999.n3.nabble.com/Fire-Rule-in-Stateless-Knowledge-Sessio... Sent from the Drools: User forum mailing list archive at Nabble.com.

11 years, 8 months

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"Rule-Id" for a Drools Rule

by harishtejwani

All: We are using Drools to detect specific events/conditions in our system. In the 'then' condition of Drools rule, we would like to persist the "Rule Id" of the rule that created the specific event/condition This is because all our reporting is based on "rules" as filters, where users can look at exceptions by specific rules. Is there a suggestion or sample as how can the "Rule Id" be persisted or indicated in the then condition that is immutable or can be long-lived. The current approach of using Rule Name itself as the ID is brittle as this can be changed and suddenly all reports would break. If we assign ID's to rules, where do we keep the mapping of RULE ID to Rules. If we store rules in GUVRNOR is there a way we can get Rule Id's for Rules? Best regards Harish Tejwani -- View this message in context: http://drools.46999.n3.nabble.com/Rule-Id-for-a-Drools-Rule-tp2914385p291... Sent from the Drools: User forum mailing list archive at Nabble.com.

11 years, 11 months

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FW: Implementation of expert system

by Binyala, Krishna Gopal IN BLR SISL

Hello, I am new to drools community... I want to develop an expert system for medical application using drools. can you please let me know how to use history data in drools... Because as far as i know we have to keep all the data in the working memory to access. How should i implement such system? Would be better if you can provide some reference to existing expert system implemented using drools. Thanks in advance. Krishna Gopal In three words I can sum up everything I've learned about life: it goes on... Important notice:This e-mail and any attachment thereto contains corporate proprietary information. If you have received it by mistake, please notify us immediately by reply e-mail and delete this e-mail and its attachments from your system. Thank You.

12 years, 1 month

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Re: [rules-users] Question about Drools Spring, StatelessKnowledgeSession and globals

by Patrick van Kann

Hello fellow Droolers, A while ago I asked why the <drools:batch> element seemed to work differently in the case of a StatelessKnowledgeSession and a StatefulKnowedgeSession (see below). I just wanted to update those interested with the answer and ask some further questions, probably aimed at any developers who happen to be reading. I checked out the 5.1.1.34858 tag and had a look at how the Spring integration works. I found that the reason that the global is not set in the case of a StatelessKnowledgeSession is because the <spring:batch> element is effectively ignored in the StatelessKnowledgeSessionBeanFactory, which lacks the following code present in the StatefulKnowledgeSessionBeanFactory (in the internalAfterPropertiesSet() method): if ( getBatch() != null && !getBatch().isEmpty()) { for ( Command<?> cmd : getBatch() ) { ksession.execute( cmd ); } } So, either by accident or design the <spring:batch> element has no effect when using a StatelessKnowledgeSession (but is perfectly allowable in the XSD/Spring namespace). So my questions are: 1) Is this the intended behaviour or a bug? On reflection, I am now not sure the idea of a "batch/script" makes sense for a StatelessKnowledgeSession since execute() is a one-shot method and any globals set this way would not be available to later executions, which is what I was looking for. 2) If so, should the XSD be changed to disallow the batch element within a stateless session (difficult, given that this is determined via the "type" attribute) or should the documentation simply warn people that the <spring:batch> element doesn't do anything if you set the type attribute to stateless (somewhat confusing, I suppose) 3) If not, should the code above be added to the StatelessKnowledgeSessionBeanFactory.internalAfterPropertiesSet() method? 4) Should there be another way to declare a global that isn't through the batch element (one that would cause globals to be set via the setGlobal(String, Object) method rather than using the SetGlobalCommand via the execute() method. I am happy to try and contribute something along these lines if I can get some guidance as to what was actually intended. Hope this helps and thanks again for Drools. Patrick ===================================== Hello, I've been trying out the Spring integration package in Drools 5.1.1 and it works really well, but I have run into one issue I can't figure out. I've defined 2 knowledge sessions from the same knowledge base in the app context - one stateless, one stateful but otherwise identical. They both refer to a collaborator defined as a bean in the app context which is to be used as a global in my rules. This is just an excerpt of my full Spring context, the kbase definition itself is not an issue. <bean id="applicantDao" class="com.acme.app.dao.impl.ApplicantDaoImpl" /> <drools:ksession id="statelessKSession" type="stateless" name="statelessKSession" kbase="kbase"> <drools:batch> <drools:set-global identifier="applicantDao" ref="applicantDao" /> </drools:batch> </drools:ksession> <drools:ksession id="statefulKSession" type="stateful" name="statefulKSession" kbase="kbase"> <drools:batch> <drools:set-global identifier="applicantDao" ref="applicantDao" /> </drools:batch> </drools:ksession> The issue is that this configuration works for the stateful but not the stateless session, in the sense that the stateful session appears to have a valid reference to the applicantDao object in the Globals object but the stateless session doesn't. <at> Test public void testStatelessGlobal() { Globals globals = statelessKSession.getGlobals(); Object global = globals.get("applicantDao"); Assert.assertNotNull(global); } <at> Test public void testStatefulGlobal() { Globals globals = statefulKSession.getGlobals(); Object global = globals.get("applicantDao"); Assert.assertNotNull(global); } The first test fails (the global variable is null) but the second passes. No errors are thrown by Drools during the setup of the Spring container. What am I doing wrong? Should I be able to define globals in this way for stateless sessions? The XSD seems to indicate this is a valid configuration, but it just doesn't work. Is anyone else working with the Spring integration that can point out my error here? Many thanks, Patrick

12 years, 1 month

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Drools: Using Declared Types in Decision Tables

by David Smith

Hi, I am trying to use a declared type in a decision table but get an "Unable to resolve ObjectType" message. The declared type is in a file types.drl, I have a spreadsheet test.xls that has a Ruleset with an import line for the declared type. Is it possible to reference a declared type from a decision table? Is it possible to declare a type in a decision table? Thanks David

12 years, 2 months

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Rules with variable timers

by Shannon Hastings

Is there a way to write a rule in DRL that uses a timer or something that is dynamic. I.E. I want the time that rule waits to fire to be dependent on a variable such as below: rule "CheckDoseMissed" no-loop timer(int: $eventA.sleepTime) when $eventA : MyEvent() ……….. ---------- Shannon Hastings Inventrio shannon.hastings(a)inventrio.com (614) 389-2795 ext: 101 http://www.inventrio.com

12 years, 2 months

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Drools Guvnor API information?

by Vikas Hazrati

Hi, I am looking at using Guvnor for our project where users would be creating rules using our UI. For this i need to add / modify rule or any asset for that matter using an api. Unfortunately, i could not find enough documentation to suggest the best way to use the REST api, which I guess is provided by Guvnor. Could someone let me know the location of where i can get some information for this api. I also see that the issue GUVNOR-1080 (https://issues.jboss.org/browse/GUVNOR-1080) is marked resolved so the api should exist right? or that we cannot access it remotely until we have the Atom Pub Interface done? Help appreciated . -- View this message in context: http://drools-java-rules-engine.46999.n3.nabble.com/Drools-Guvnor-API-inf... Sent from the Drools - User mailing list archive at Nabble.com.

12 years, 4 months

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enquiry on drools webservice

by Prem Kumar L

12 years, 4 months

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java.lang.OutOfMemoryError: Java heap space

by vdelbart

Hello, In my tests of the 4.0.3, I have some : java.lang.OutOfMemoryError. So, I try a simple test with 10.000 sequential execution of 1 rule with no context and just a workingmemorylogger and I have the error : java.lang.OutOfMemoryError: Java heap space My code is : public class ExecReglesMemotyTest { private static final Reader DRL = new InputStreamReader(ExecReglesMemotyTest.class .getResourceAsStream("/rules/exemple.drl")); private static final String FICHIER_LOG = "session"; /** * @param args */ public static void main(String[] args) { try { PackageBuilder builder = new PackageBuilder(); builder.addPackageFromDrl(DRL); RuleBase ruleBase = RuleBaseFactory.newRuleBase(); ruleBase.addPackage(builder.getPackage()); for (int i = 0; i < 10000; i++) { StatefulSession session = ruleBase.newStatefulSession(); WorkingMemoryFileLogger logger = new WorkingMemoryFileLogger(session); logger.setFileName(FICHIER_LOG); session.fireAllRules(); logger.writeToDisk(); session.dispose(); } } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } } with this rule (doesn't matter): #created on: Fri Nov 09 15:48:45 CET 2007 package initPackage #list any import classes here. rule "ERG9" when then end I try this in 4.0.1, and it's working (no OutOfMemoryError) What's the problem ? thanks for any information, V. -- View this message in context: http://www.nabble.com/java.lang.OutOfMemoryError%3A-Java-heap-space-tf477... Sent from the drools - user mailing list archive at Nabble.com.

12 years, 4 months

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Unable to find implementation for BusinessRuleProvider

by John Peterson

Hi, I've been experimenting with the Guided Rule Editor plug-in in Eclipse. I've built a Drools Project using the default Hello World sample application. I've created a new "Guided Rule" in my project called "GuidedRule.brl" and get the associated "drools.package" with it. The rule is simple: WHEN THEN System.out.println("Rule has fired"); I build the knowledge base as follows: private static KnowledgeBase readKnowledgeBase() throws Exception { KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder(); kbuilder.add(ResourceFactory.newClassPathResource("SampleGuided.drl"), ResourceType.BRL); KnowledgeBuilderErrors errors = kbuilder.getErrors(); if (errors.size() > 0) { for (KnowledgeBuilderError error: errors) { System.err.println(error); } throw new IllegalArgumentException("Could not parse knowledge."); } KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase(); kbase.addKnowledgePackages(kbuilder.getKnowledgePackages()); return kbase; } The only line changed is adding the resource of type BRL. When I try to run, I get the following error: java.lang.RuntimeException: org.drools.compiler.DroolsParserException: org.drools.CheckedDroolsException: Unable to find implementation for BusinessRuleProvider at org.drools.compiler.PackageBuilder.addKnowledgeResource(PackageBuilder.j ava:544) at org.drools.builder.impl.KnowledgeBuilderImpl.add(KnowledgeBuilderImpl.ja va:28) at com.sample.DroolsTest.readKnowledgeBase(DroolsTest.java:41) at com.sample.DroolsTest.main(DroolsTest.java:23) Caused by: org.drools.compiler.DroolsParserException: org.drools.CheckedDroolsException: Unable to find implementation for BusinessRuleProvider at org.drools.compiler.PackageBuilder.addPackageFromBrl(PackageBuilder.java :386) at org.drools.compiler.PackageBuilder.addKnowledgeResource(PackageBuilder.j ava:470) ... 3 more Caused by: org.drools.CheckedDroolsException: Unable to find implementation for BusinessRuleProvider at org.drools.compiler.BusinessRuleProviderFactory.throwNoImplementationFou nd(BusinessRuleProviderFactory.java:66) at org.drools.compiler.BusinessRuleProviderFactory.loadProvider(BusinessRul eProviderFactory.java:42) at org.drools.compiler.BusinessRuleProviderFactory.getProvider(BusinessRule ProviderFactory.java:25) at org.drools.compiler.PackageBuilder.addPackageFromBrl(PackageBuilder.java :366) ... 4 more I've tried variations to add the drools.package as a PKG type, I've had the rules (and package) in both "com.sample" and /src/main/rules, but I can't seem to resolve the problem. "drools.package" has been updated to include the package name (package com.sample;) and I import the message class as well (even though it isn't being used currently). I suspect the issue is simple, but I haven't been able to figure it out. Any help would be appreciated.

12 years, 5 months

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rules-users October 2011