[rules-users] Multi-threading inefficiency caused by static class synchronization?

[ping]

hi Salaboy,
Thank you for your reply. I read some of your blog posts and find them very
helpful for my learning of Drools.

But for the question I raised here, "create multiple stateless sessions with
the same rules in different threads" is exactly what I was trying. But I
found that the rule engine can only utilized 20% of the total CPU resources.
In my test, I have 8 threads running and ideally they should use all cpu
resource on my 8 core machine. Here's my test program with 8 threads:

public class DroolsMultithreadTest implements Runnable {
    private static KnowledgeBase kbase;
    private static KnowledgeBuilder kbuilder;
    static int times = 10000;

    public DroolsMultithreadTest() {
    }

    public static void main(String args[]) throws Exception {
        kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();
        kbuilder.add( ResourceFactory.newClassPathResource("change-set.xml",
DroolsMultithreadTest.class), ResourceType.CHANGE_SET );
        if ( kbuilder.hasErrors() ) {
            System.out.println( kbuilder.getErrors().toString() );
            throw new RuntimeException( "Unable to compile rules." );
        }

        KnowledgeBaseConfiguration kbConfiguration =
KnowledgeBaseFactory.newKnowledgeBaseConfiguration();

        kbConfiguration.setOption(SequentialOption.YES);

        kbase = KnowledgeBaseFactory.newKnowledgeBase(kbConfiguration);
        // get the compiled packages (which are serializable)
        kbase.addKnowledgePackages( kbuilder.getKnowledgePackages() );


        long startTime = System.currentTimeMillis();
        Thread[] threads = new Thread[8];

        for (int i=0; i<8; i++) {
            threads[i] = new Thread(new DroolsMultithreadTest());
            threads[i].start();
        }

        for (int i=0; i<8; i++) {
            threads[i].join();
        }


        System.out.println("Time spent (ms): " + (System.currentTimeMillis()
- startTime));
        System.out.println("Time/request (ms): " +
((System.currentTimeMillis() - startTime))/times);

        System.exit(0);
    }


    @Override
    public void run() {
        for (int i=0; i<times; i++) {
            // get the declared FactType
            FactType transactionType = kbase.getFactType( "Demo",
"Transaction");
            // handle the type as necessary:
            // create instances:
            Object txn = null;
            try {
                txn = transactionType.newInstance();
            } catch (InstantiationException e) {
                e.printStackTrace();
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            }
            // set attributes values
            transactionType.set( txn,
                    "txnId",
                    (i+1)*100L );
            transactionType.set( txn,
                    "amount", new BigDecimal(i%10) );

            // insert fact into a session
            StatelessKnowledgeSession ksession =
kbase.newStatelessKnowledgeSession();
            CacheQueryService queryService =
CacheQueryServiceImpl.getInstance();
            ksession.setGlobal("cacheQueryService", queryService);

            ksession.execute(txn);

        }
    }
}

Thanks,
-Ping



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