Re: [rules-users] Inconsistency in Drools' Performance (Version 5.5.0)

Hi, I have been trying to measure Drools' 5.5.0 performance for quite some time. I see that Drools' perform inconsistently in terms of CPU time. Please see the below code (modification of DroolsTest example): /*Code start*/ public class DroolsTest { public static final void main(String[] args) { try { // load up the knowledge base KnowledgeBase kbase = readKnowledgeBase(); // go ! for (int i = 0; i < 20; i++) { Message message = new Message(); message.setMessage("Hello World"); message.setStatus(Message.HELLO); long startTime = System.nanoTime(); StatefulKnowledgeSession ksession = kbase.newStatefulKnowledgeSession(); FactHandle handle = ksession.insert(message); ksession.fireAllRules(); ksession.retract(handle); System.out.println("Time taken is: " + (System.nanoTime()-startTime)/1000); ksession.dispose(); } } catch (Throwable t) { t.printStackTrace(); } } private static KnowledgeBase readKnowledgeBase() throws Exception { KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder(); kbuilder.add(ResourceFactory.newClassPathResource("Sample.drl"), ResourceType.DRL); 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; } public static class Message { public static final int HELLO = 0; public static final int GOODBYE = 1; private String message; private int status; public String getMessage() { return this.message; } public void setMessage(String message) { this.message = message; } public int getStatus() { return this.status; } public void setStatus(int status) { this.status = status; } } } /** Code end**/ I have just added timing code to the DroolsTest.java program (provided by JBoss) and I am using Sample.drl file (provided by JBoss). The rules get executed correctly but the timings that I see are: Iteration 1: 103753 (we can ignore this as the classes get loaded during the first iteration) Iteration 2: 861 Iteration 3: 744 Iteration 4: 1350 Iteration 5: 718 Iteration 6: 651 Iteration 7: 661 Iteration 8: 668 Iteration 9: 648 Iteration 10: 3564 Iteration 11: 911 Iteration 12: 689 Iteration 13: 682 Iteration 14: 796 Iteration 15: 4236 Iteration 16: 774 Iteration 17: 772 Iteration 18: 722 Iteration 19: 713 Iteration 20: 697 I profiled it with Yourkit Profiler and the increase in time does not correspond to garbage collection. I also timed individual calls and found out that: - ksession.insert: takes consistent time - ksession.fireAllRules: inconsistent - kbase.newStatefulKnowledgeSession: inconsistent I see same inconsistency in performance when I integrate Drools with original project (which I can't share here). I also found that this has nothing to do with compiler optimizations. Why is there inconsistent performance? Is there anything that I am missing? Thank you. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users