I posted about caching and after some more investigation it appears the problem lies in just refreshing the rulebase. I created a simple package that contains 1 excel decision table which has 1 rule [row] in it. I ran my application. Then rebuilt the package in the Guvnor and my application refreshed the rule base correctly. I have other packages which contain many 100 rules if not 1000 rules all based on multiple excel based decision tables. If I run my application, then rebuild the package in the Guvnor, my application throws the exception. RuleAgent(Assembly) EXCEPTION (Fri Feb 26 12:02:32 EST 2010): java.lang.ClassCastException: org.drools.util.ObjectHashMap cannot be cast to org.drools.reteoo.BetaMemory. Stack trace should follow. org.drools.RuntimeDroolsException: java.lang.ClassCastException: org.drools.util.ObjectHashMap cannot be cast to org.drools.reteoo.BetaMemory It appears the problem occurs where there are many rules. Any ideas? Thanks. ________________________________ From: rules-users-bounces(a)lists.jboss.org on behalf of Jeffrey Schneller Sent: Fri 2/26/2010 12:18 PM To: rules-users(a)lists.jboss.org Subject: [rules-users] Caching RuleBase I saw some old thread about caching the rule base on your own. I have a singleton which contains a hashmap to do the caching. I am using the Guvnor to pull my rules from. This works fine except when the rules change on the Guvnor. When the rule base tries to refresh in my application, I am getting a ClassCastException. Any ideas? RuleAgent(Assembly) EXCEPTION (Fri Feb 26 12:02:32 EST 2010): java.lang.ClassCastException: org.drools.util.ObjectHashMap cannot be cast to org.drools.reteoo.BetaMemory. Stack trace should follow. org.drools.RuntimeDroolsException: java.lang.ClassCastException: org.drools.util.ObjectHashMap cannot be cast to org.drools.reteoo.BetaMemory My code to do the caching is below: private HashMap<String, RuleBase> ruleBaseMap = new HashMap<String, RuleBase>(); // check to see if we already set up this rule base if (ruleBaseMap.containsKey(product.getConfigurationRule())) { rb = ruleBaseMap.get(product.getConfigurationRule()); } else { try { InitialContext context = new InitialContext(); url = (String) context.lookup("java:comp/env/rules.url"); url = url + product.getConfigurationRule() + "/LATEST"; } catch (NamingException e1) { } Properties config = new Properties(); config.setProperty("newInstance", "false"); config.setProperty("url", url); config.setProperty("poll", "300"); config.setProperty("name", "Assembly"); RuleAgent agent = RuleAgent.newRuleAgent(config); rb = agent.getRuleBase(); ruleBaseMap.put(product.getConfigurationRule(), rb); }