topic Re: Process instance execution happening sequentially in Alfresco Archive

Process instance execution happening sequentially

pavlos — Mon, 05 Nov 2012 14:35:00 GMT

Hello,I have a process definition containing a service task that takes a few seconds to run. For performance reasons, I would like to run several instances of this process in parallel. I start each process instance in a for loop: for (SomeEntity e : entities) { LOG.info("Processing

Re: Process instance execution happening sequentially

webcyberrob — Mon, 05 Nov 2012 22:33:17 GMT

My understanding of what may be happening is if your process template is not explicitely tagged with asynchronous, then the process instance will execute to the first wait state in the process using the client thread. Hence in your case you may see that all the process instances start and execute in the context of the looping client thread and thus you will get serial execution.

From the user guide

"…If you trigger Activiti (i.e. start a process, complete a task, signal an execution), Activiti is going to advance in the process, until it reaches wait states on each active path of execution. More concretely speaking it performs a depth-first search through the process graph and returns if it has reached wait states on every branch of execution. A wait state is a task which is performed "later" which means that Activiti persists the current execution and waits to be triggered again. …"

Check out the section on asynchronous continuations in the user guide, there's a good diagram which will hopefully clarify.

R

Re: Process instance execution happening sequentially

pavlos — Tue, 06 Nov 2012 08:13:32 GMT

Thank you for your answer, webcyberrob. You're apparently right. Every process instance will be executed in its parent thread. Only the JobExecutor will start jobs in another thread and this will only happen, as you pointed out, if a wait state has been reached, a task has the async flag set to true or a timer event fires.

Greetings,
Pavlos