[Engine-devel] Task Manager Design Review

[Moti Asayag]

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?
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.