topic Re: Resuming workflow in Alfresco Archive

Resuming workflow

kanchan — Tue, 25 Feb 2014 13:55:03 GMT

Hi,We are currently exploring activiti to use in our project. Out of which one of the topic is how saved workflows are resumed in activiti.My scenario is service task1 -> catchTimerEvent->Service task2. In this case if the engine crashes in between say after catchTimerEven What happens to the

Re: Resuming workflow

hardik_kaji — Wed, 26 Feb 2014 05:13:26 GMT

Hi Kanchan,

Can you share activiti diagram or Unit test case for same?

Re: Resuming workflow

kanchan — Wed, 26 Feb 2014 05:19:50 GMT

Thanks for the reply..
In above scenario I could resume the process instance from timer event. Now I want to know what will happen in case there is script task or any other task instead of timer(wait state) and engine stops or crashes while executing script task. Will it resume from crash state or from begining in next run ? Which will be the safe state for this ?
Earlier my workflow was ->

start event -> service task -> Timer -> script task -> end event

Now I want to know about this scenario ->

start event -> service task -> script task -> script task -> end event

Many thanks in advance

Re: Resuming workflow

martin_grofcik — Wed, 26 Feb 2014 07:28:05 GMT

Hi Kanchan,

let's say that start event is None Start Event and process is started by
runtimeService.startProcessInstanceByKey….
and there is no asynchronous task between start -> script.
In that case method call will throw an exception.

Regards
Martin

Re: Resuming workflow

kanchan — Wed, 26 Feb 2014 10:05:04 GMT

Hi Martin,

Yes,I have the same workflow without any asynchronous task :
None start event -> script task -> service task1 -> script task -> end event

But I'm not getting any exception. My question is if engine is crashed/restarted at service task1 while executing some script, the next time when I rerun the workflow,from where this suspended workflow will get resumed? beginning i.e. start event or the crash point?

Thanks,
Kanchan

Re: Resuming workflow

martin_grofcik — Thu, 27 Feb 2014 07:37:17 GMT

Hi Kanchan.

In the case when process is interrupted between two wait states (crash….) transaction is not committed and that's why process instance should be in the same state as it was before the transaction start.
more info:
http://www.activiti.org/userguide/#bpmnConcurrencyAndTransactions

Regards
Martin

Re: Resuming workflow

kanchan — Thu, 27 Feb 2014 16:30:26 GMT

Hi Martin,

You mean the transaction will not be persisted until and unless it reaches to the wait state. If there is no wait state in workflow, the process will always resume from start point in case it's interrupted in between. Please correct me if I have misunderstood anything.

Thanks a lot,
Kanchan

Re: Resuming workflow

trademak — Sat, 01 Mar 2014 13:53:13 GMT

Hi Kanchan,

That's correct. When an exception occurs and no wait state is reached to whole process instance will be rolled back until the starting point.

Best regards,

Re: Resuming workflow

kanchan — Sun, 02 Mar 2014 12:56:35 GMT

Thanks all for the reply.
Please provide me the details on support cost that activiti team charges.

-Kanchan

Re: Resuming workflow

kanchan — Mon, 03 Mar 2014 09:12:15 GMT

Hi,

I also want to know about How we can achieve Throttling for multi-instance constructs in activiti.

Thanks in advance,
Kanchan

Re: Resuming workflow

jbarrez — Mon, 10 Mar 2014 10:04:35 GMT

@Kanchan: more info: http://activiti.org/enterprise-support.html

* The throttling you mention is not in Activiti built-in and would need to be a customisation.

Re: Resuming workflow

kanchan — Fri, 14 Mar 2014 06:06:46 GMT

Hi,

I am getting optimistic locking exception for parallel asynch tasks. When I searched for the solutions, I found there is a way to avoid this exception by introducing camel task. Is it true? or please let me know the other ways, how can I avoid this exception. My workflow is :
start -> fork->parallet task1->join-> end
->parallel task2->

One more query on session management. jbpm has session management on knowledge base where the session is created for each process instance. Do we have similar things in activiti also?

Awaiting your response.

Thanks in advance,
Kanchan

Re: Resuming workflow

martin_grofcik — Mon, 17 Mar 2014 08:41:32 GMT

Hi Kanchan,

camel task.

May be you can use exclusive jobs. http://www.activiti.org/userguide/#exclusiveJobs

Regards
Martin

Re: Resuming workflow

kanchan — Mon, 17 Mar 2014 10:38:28 GMT

Waiting for reply on second question from previous thread
"
jbpm has session management on knowledge base where the session is created for each process instance. Do we have similar things in activiti also?
"

Re: Resuming workflow

martin_grofcik — Tue, 18 Mar 2014 07:47:56 GMT

Hello Kanchan.

I got in touch with jBPM5.X so little that I do not know.

Regards

Re: Resuming workflow

kanchan — Tue, 18 Mar 2014 08:58:13 GMT

Hi Martin,

So in Activiti how sessions are created and managed ? What are different session management strategies ? does engine support multiple sessions ? How is process synchronization handled in a session?
I couldn't fine much information on sessions in Activiti, so thought to ask here itself.

Thanks in advance,
Kanchan

Re: Resuming workflow

jbarrez — Mon, 24 Mar 2014 11:42:29 GMT

The reason is simple: we don't use session.

Activiti is 100% stateless and as such using sessions goes against that principle.

Re: Resuming workflow

kanchan — Wed, 26 Mar 2014 13:00:39 GMT

Hi,

For support related queries I found information on following page :
http://www.alfresco.com/services/subscription/technical-support

The support cost is not specified for Departmental and Enterprise Support packages there. Are they free?

Thanks in advance,
Kanchan