Will advise soon, out sick with not so fun case of poison oak, will reply next 
week (hopefully) when I'm less incapacitated...
Sent from my really tiny device...

On Mar 21, 2014, at 3:24 AM, "Renat Akhmerov" 
<rakhme...@mirantis.com<mailto:rakhme...@mirantis.com>> wrote:

Valid concerns. It would be great to get Joshua involved in this discussion. If 
it’s possible to do in TaskFlow he could advise on how exactly.

Renat Akhmerov
@ Mirantis Inc.



On 21 Mar 2014, at 16:23, Stan Lagun 
<sla...@mirantis.com<mailto:sla...@mirantis.com>> wrote:

Don't forget HA issues. Mistral can be restarted at any moment and need to be 
able to proceed from the place it was interrupted on another instance. In 
theory it can be addressed by TaskFlow but I'm not sure it can be done without 
complete redesign of it


On Fri, Mar 21, 2014 at 8:33 AM, W Chan 
<m4d.co...@gmail.com<mailto:m4d.co...@gmail.com>> wrote:
Can the long running task be handled by putting the target task in the workflow 
in a persisted state until either an event triggers it or timeout occurs?  An 
event (human approval or trigger from an external system) sent to the transport 
will rejuvenate the task.  The timeout is configurable by the end user up to a 
certain time limit set by the mistral admin.

Based on the TaskFlow examples, it seems like the engine instance managing the 
workflow will be in memory until the flow is completed.  Unless there's other 
options to schedule tasks in TaskFlow, if we have too many of these workflows 
with long running tasks, seems like it'll become a memory issue for mistral...


On Thu, Mar 20, 2014 at 3:07 PM, Dmitri Zimine 
<d...@stackstorm.com<mailto:d...@stackstorm.com>> wrote:

For the 'asynchronous manner' discussion see http://tinyurl.com/n3v9lt8; I'm 
still not sure why u would want to make is_sync/is_async a primitive concept in 
a workflow system, shouldn't this be only up to the entity running the workflow 
to decide? Why is a task allowed to be sync/async, that has major side-effects 
for state-persistence, resumption (and to me is a incorrect abstraction to 
provide) and general workflow execution control, I'd be very careful with this 
(which is why I am hesitant to add it without much much more discussion).

Let's remove the confusion caused by "async". All tasks [may] run async from 
the engine standpoint, agreed.

"Long running tasks" - that's it.

Examples: wait_5_days, run_hadoop_job, take_human_input.
The Task doesn't do the job: it delegates to an external system. The flow 
execution needs to wait  (5 days passed, hadoob job finished with data x, user 
inputs y), and than continue with the received results.

The requirement is to survive a restart of any WF component without loosing the 
state of the long running operation.

Does TaskFlow already have a way to do it? Or ongoing ideas, considerations? If 
yes let's review. Else let's brainstorm together.

I agree,
that has major side-effects for state-persistence, resumption (and to me is a 
incorrect abstraction to provide) and general workflow execution control, I'd 
be very careful with this
But these requirement  comes from customers'  use cases: wait_5_day - lifecycle 
management workflow, long running external system - Murano requirements, user 
input - workflow for operation automations with control gate checks, provisions 
which require 'approval' steps, etc.

DZ>


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--
Sincerely yours
Stanislav (Stan) Lagun
Senior Developer
Mirantis
35b/3, Vorontsovskaya St.
Moscow, Russia
Skype: stanlagun
www.mirantis.com<http://www.mirantis.com/>
sla...@mirantis.com<mailto:sla...@mirantis.com>
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