JBoss 6.1.0.Final SFSB concurrency issue
popoctavian Jul 19, 2013 11:19 AMHi,
I am trying to run a test to investigate a performace issue after upgrading from JBoss 4.0.5 to 6.1. For this I use a simple test application with a service which starts threads, each thread looks-up a SFSB instace and execute a method to increment a number.
From this test I notticed that SFSB method calls in the multi-threaded test are serialized - one execution after the other. Investigating in more detail I found that this serialization is caused by CMC interceptor from server/current/deploy/ejb3-interceptors-aop.xml.
If I commented out CMC, performance increased significantly.
Is this a known behavior?
What are the implications if I comment CMC?
Thanks.
Below are code snippets from test:
@Service
public class TestingService
{
    public static int numberOfThreads=2;
    public static void start() throws Exception
    {
        startTest(numberOfThreads);
    }
    public static void startTest(int threadNumber) throws InterruptedException
    {
        Thread [] threads = new Thread[threadNumber];
        for (int i=0;i< threadNumber;i++)
        {
            Thread t = new Thread()
            {
                public void run()
                {
                    Client testClient = new Client();
                    testClient.processNumber(Math.round(Math.random()*1000));
                    testClient.destroy();
                }
            };
            t.start();
            threads[i] = t;
        }
        for(int i=0; i<threadNumber; i++)
        {
            threads[i].join();
        }
    }
}
public class Client
{
    IGenericSFB genericSFB;
    public Client()
    {
        genericSFB = (IGenericSFB) ServiceLocator.getLocalService(GenericSFB.class.getSimpleName());
        System.out.println("This address " + genericSFB + " " + genericSFB.hashCode());
    }
    public void processNumber(Long number)
    {
        System.out.println("Client - Start incrementing " + number);
        genericSFB.incrementNumber(number);
        System.out.println("Client - Finish incrementing " + number);
    }
...
@Stateful
public class GenericSFB implements IGenericSFB, Serializable
{
    private int number;
    private String stuff;
    private String someOtherStuff;
    public Long incrementNumber(Long number)
    {
        System.out.println("SFB - start incrementing number " + number + " by " + this);
        try
        {
            Thread.currentThread().sleep(10000);
        }
        catch (InterruptedException e){}
        System.out.println("SFB - finish incrementing number " + number);
        return 0L;
    }
...
 
    