Hi,

We have a project where we are attempting to add new rules to an existing knowledgebase (read from a .drl file). We add them by using strings using the following code:

String rule = "rule \"GeneralClause-2\" " +
            "when " +
                "ObligationComplianceEvent(term == \"term2\", obligation == \"obligation1\", level == 2) " +
            "then " +
                "System.out.println(\"GeneralClause-2\");" +
                "contract1.setState(\"Hello\");" +
            "end";

Resource ruleResource = ResourceFactory.newReaderResource((Reader) new StringReader(rule));
kbuilder.add(ruleResource, ResourceType.DRL);
kbase.addKnowledgePackages(kbuilder.getKnowledgePackages());

We do not even halt the currently running session to add the new rule (although halting and re-firing appears to make little difference). This appears to have strange effects. Some rules (specifically those that use 'accumulate' most of the time) will stop working after inserting the new rule at runtime, even though they are completely unrelated. The timing in which you add the new rule also seems to have an effect (e.g. before inserting some events, after. etc). We cant seem to come to any logical conclusion about the strange behavior our rules seem to give us.

My question is this: Is this a valid way to use Drools? Or are we somehow breaking something (perhaps the rete tree or something) behind the scenes by doing this? If so, is there a correct way?

Any input at all would be greatly appreciated as this is very critical to our project.

Cheers,

Justin