topic Re: Async Camel task not called in Alfresco Archive

Async Camel task not called

tomas_surovec — Fri, 24 May 2013 09:25:55 GMT

Hi, I have an issue with calling async camel service tasks, which is fairly similar to this thread: http://forums.activiti.org/content/async-service-task-not-executingI have a diagram with parallel gateway forking into two branches, on each branch there are two camel service tasks, followed by join

Re: Async Camel task not called

frederikherema1 — Tue, 04 Jun 2013 13:41:01 GMT

Is your job-executor on? Because async activities are executed by that, the call that causes the activities to be queued for execution, returns immediately. That's why the API-call returns…

Re: Async Camel task not called

tomas_surovec — Tue, 04 Jun 2013 13:54:57 GMT

Hi,

yes, that was the issue, thank you!

Re: Async Camel task not called

frederikherema1 — Tue, 04 Jun 2013 15:02:16 GMT

Glad it works!

Re: Async Camel task not called

tomas_surovec — Tue, 04 Jun 2013 16:21:51 GMT

Although I have another problem: the setup is fairly simple:
START ———> ServiceTask A ————-> ServiceTask B ————–> END

both service tasks are camel tasks that just call a prototype bean's method that just writes out thread id and sleeps for a few seconds on that
thread. Now
1) A, B async = false -> serial call as expected on the same "main" thread
2) A async = false, B async = true -> serial call, second call on different thread (as expected)
3) A async = true, B async = false -> serial call (not expected), second call on the same thread as the first (also not expected behavior)
4) A, B async = true -> B isn't called at all

(btw. acitviti:exclusive="false" always)

I thought that async service task call means that the service is called asynchronously from main thread (the service call being
executed on a different thread) and the main thread continues without blocking, i.e. in 3) it should start executing B immediately and on different
thread than A. Apparently async calls don't work the way I thought - my question is how can I manage to start executing both A and B
concurrently? In other words I want that both service tasks use their own thread, different from "main" thread.

Re: Async Camel task not called

frederikherema1 — Thu, 06 Jun 2013 12:25:36 GMT

Async indeed means that the activity is executed in another thread, returning control to the main-thread and committing process-state up until the point where the async should start.

3 -> The second task will only be executed once the asynchronous A is complete. When the A is completed by the job-executor thread, it executes B as well on that thread (and any subsequent non-async activities until a wait state or process-end has been reached).

If you want to have both A and B executing at the same time, use a parallel gateway and async=true.