clarification about process execution

[antonio.giambanco]

Hi all,

I have a question about the way process are executed . . .

Making some tests I found out that:

1. if I call a process ( start-->[HumanTask]-->[HumanTask]-->end ) through an external java client, bpm engine starts an instance, it goes to the first human task and it releases the client.
2. if I call a process ( start-->[ScriptTask]-->[ScriptTask]-->end ) through an external java client, bpm engine starts an instance, it goes to the end and then it releases the client.

I noticed behavior (2) because I was not handling correctly errors on the second ScriptTask so on a problem I received the exception on my client.

Is it normal? I thought in any case my client was creating an instance of the process, having and instanceID and after that released at the start.

[salaboy21]

Hi Antonio,

yes that's the correct behaviour and standard one.

HumanTasks creates a safe point where the process can be stored. In the other hand the ScriptTasks doesn't do that and they are executed in the same run as the rest of the process.

If you want to make sure that the process is persisted you can use a WorkItemHandler that doesn't complete the task and later on complete the task, making the node Async.

I've explained this behaviour in my two jBPM books: http://www.amazon.co.uk/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=jbpm+developer+guide

But I totally recommend Mariano's one which is updated to version 6.

HTH

Regards

[antonio.giambanco]

Hi Mauricio

yesterday I bought version 6 . . .if I still have problem I will ask you more information.

anyway seems very clear if I need to execute an async task inside the process but it is not so clear if I need to execute an entire async process from and external java call

thanks!

[salaboy21]

Antonio, if you want to start a process in an asynchronous you can create a new Command for the jbpm-executor, that will start the process until the next async task. If you make the first task async as well (or even all the tasks async) you will have full control of the process at every step.

Regards

[antonio.giambanco]

Thanks Mauricio

Do I have the same control of the entire process even if I don't have any async task (regular table or script tasks) in my process?

I need just to instantiate my process asynchronously

[antonio.giambanco]

HiMauricio

I read the entire book and I found many interisting tips on jbpm6, I found useful chap10 and this post jBPM executor for embedded applicatin in Eclipse but I don't understand how it's possible to execute my process asynchronously.

I mean I don't need to have an async execution of a task inside my process but just calling my process from a remote client, having the process instance id and let it go (I don't care if it fails or finishes in many day).

Is JMS command invocations a way? Is it the only way?

Thanks

[antonio.giambanco]

HiMauricio,

I better read your last post and:

Since I would like to avoid async task

having just ( start-->[ScriptTask]-->[ScriptTask]-->end ) so no async taskes, I'm trying to understand if there is a workaround?

thanks a lot