Java – Correct way to use EJB Asynchronous methods

asynchronousejbjakarta-eejavawebsphere

I have two tasks that I need to perform say task1 and task2 which are a part of same business process. I have to give response to the end user when task1 completes so it's response time have to be minimized.

My current approach is to perform task1 and as soon as task1 is finished, invoke task2 method asynchronously. task2 is complicated and it's response time is out of my control as it has some external dependency.

@Stateless
public class SessionBean1 {

    @Inject
    SessionBean2 sessionBean2;

    public void doTask1(){
        // task one stuff
        sessionBean2.doTask2();
    }

}



@Stateless
public class SessionBean2 {

    @Asynchronous
    public void doTask2(){
        // do task2 stuff
    }

}

In websphere 8.0 (the EJB container in use) synchronous methods and asynchronous methods are run by different thread pools.

My initial assumption was that even if task2 is performing badly, task1 would have no impact, but sadly that's not true.

If task2 is performing badly, all threads from asynchronous thread pool will be occupied. This will cause task1 to wait for asynchronous threads to be free and hence task1 has impact.

The message in websphrere server logs :
The request buffer for thread pool WorkManager.WebSphere_EJB_Container_AsynchMethods_Internal_WorkManager has reached its capacity

My question is what would be a proper way to achieve what I'm trying to achieve here.

Best Answer

Another alternative would be to increase the "Work request queue size" of the "EJB asynchronous method invocation settings" in the Admin Console. This is a queue, before the actual thread pool itself, so this might buy you some more time.

Ideally this should be used in combination with the timeouts suggested above.

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Some 10 years later perhaps the best way to test a private method, or any inaccessible member, is via @Jailbreak from the Manifold framework.
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If you have somewhat of a legacy Java application, and you're not allowed to change the visibility of your methods, the best way to test private methods is to use reflection.

Internally we're using helpers to get/set private and private static variables as well as invoke private and private static methods. The following patterns will let you do pretty much anything related to the private methods and fields. Of course, you can't change private static final variables through reflection.

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Here's what your code would look like if changed as suggested:

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