[rules-users] KnowledgeAgent not reloading KnowledgeBase

Before I ask the problem, here's the design I currently have: Our "site" (webapp) has 100 pages. While rendering each page, the rule engine is called for filtering the page contents. We have 100 drl files (corresponding to each page). Since creating of a KnowledgeBase is expensive, I'm using a KnowledgeAgent.getKnowledeBase() since the javadocs mentions it as "it loads, caches, reloads knowledgeBase." However after using the sample code given, a change in the rule file is not reloading the knowledgeBase automatically. Note that I cache the knowledgeAgent since I need one agent per knowledge base (is there a better way to manage multiple drl files in one knowledge base and agent?) Is something wrong with the below code? // ruleFile is a complete file path on server public static KnowledgeBase createKnowledgeBaseFromAgent(String ruleFile) throws DroolsParserException, IOException { ResourceChangeScannerConfiguration sconf = ResourceFactory .getResourceChangeScannerService() .newResourceChangeScannerConfiguration(); // static map of knowledgeAgents if (knowledgeAgents.containsKey(ruleFile)) { return ((KnowledgeAgent)knowledgeAgents.get(ruleFile)).getKnowledgeBase(); } sconf.setProperty("drools.resource.scanner.interval", "5"); ResourceFactory.getResourceChangeScannerService().configure(sconf); KnowledgeBase knowledgeBase = createKnowledgeBase(ruleFile); ResourceFactory.getResourceChangeScannerService().start(); ResourceFactory.getResourceChangeNotifierService().start(); KnowledgeAgentConfiguration conf = KnowledgeAgentFactory.newKnowledgeAgentConfiguration(); conf.setProperty("drools.agent.scanDirectories", "true"); final KnowledgeAgent agent = KnowledgeAgentFactory.newKnowledgeAgent( "my agent", knowledgeBase, conf); // agent.applyChangeSet(ResourceFactory.newFileResource(ruleFile)); setKnowledgeAgent(ruleFile, agent); return agent.getKnowledgeBase(); } public static KnowledgeBase createKnowledgeBase( KnowledgeBaseConfiguration config, KnowledgeBuilderConfiguration knowledgeBuilderConfig, String ruleFile) throws DroolsParserException, IOException { // else, create a knowledgeBase KnowledgeBuilder knowledgeBuilder = KnowledgeBuilderFactory.newKnowledgeBuilder(knowledgeBuilderConfig); knowledgeBuilder.add(ResourceFactory.newFileResource(ruleFile), ResourceType.DRL); if (knowledgeBuilder.hasErrors()) { throw new RuntimeException(knowledgeBuilder.getErrors().toString()); } KnowledgeBase knowledgeBase = KnowledgeBaseFactory.newKnowledgeBase(config); knowledgeBase.addKnowledgePackages(knowledgeBuilder.getKnowledgePackages()); return knowledgeBase; } I commented out agent.applyChangeSet(ResourceFactory.newFileResource(ruleFile)); since I get a NPE java.lang.NullPointerException at org.drools.agent.impl.KnowledgeAgentImpl.processChangeSet(KnowledgeAgentImpl.java:135) Pl suggest -- View this message in context: http://n3.nabble.com/KnowledgeAgent-not-reloading-KnowledgeBase-tp121401p... Sent from the Drools - User mailing list archive at Nabble.com.