[Engine-devel] Task Manager Design Review

[Yair Zaslavsky]

On 01/02/2012 10:12 AM, Moti Asayag wrote:
> On 01/02/2012 09:53 AM, Itamar Heim wrote:
>> On 01/02/2012 02:02 AM, Moti Asayag wrote:
>> ...
>>
>>>>
>>>> 5. requirements: what about internal tasks originated by the system (SPM
>>>> election, live migration due to load balancing, fencing taking place,
>>>> refresh of users from a directory, etc.)?
>>> It was discussed on the meeting held today. It was agreed to report for
>>> specific internal action such as VM migration, Host fencing,... but not
>>> for the event itself (in order to prevent from flooding the Tasks view
>>> from frequent events).
>>
>> I think SPM election/status is an interesting enough task that if it
>> happens it should be documented (as well as its process/results).
>>
>>>
>>>>
>>>>
>>>> 6. STEP table, start_time is "not null" - shouldn't it be nullable?
>>> No. The Step is created in adjust to the execution unit it describes. In
>>> order to prevent from additional update, it should be created with
>>> status Started and start time.
>>
>> oh - I thought a job is pre-defined with its steps, then the backend
>> runs them.
>> from your reply i understand the job/steps are just documentation of
>> what already happened?
Actually, also of what is already happening, If I understand correctly.

> Correct. The Command implementation will determine by code when to add a
> step and how to decide it ended. A default implementation is provided
> for all commands, except those which specified on the requirements to be
> more detailed.
> 
> Doing the other way (let the flow definition execute the steps) means
> implementing a business process manager (or using existing one - such as
> jBPM). I don't think the backend as implemented now is capable of
> adjusting to it and letting external service orchestrate the flow.
> 
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