Open Stack

On 05/02/2013 10:51 AM, Gabe Westmaas wrote:
> On May 2, 2013, at 8:30 AM, Zane Bitter <zbitter at redhat.com> wrote:
> 
>> On 30/04/13 21:23, Russell Bryant wrote:
>>> Greetings,
>>>
>>> The following blueprint was proposed for the havana series:
>>>
>>>     https://blueprints.launchpad.net/nova/+spec/scheduled-images
>>>
>>> Based on the current design, I think the nova part of this needs to be
>>> deferred.  It does not seem appropriate to add an API extension that
>>> talks to a service that is not an integrated project, or at least incubated.
>>>
>>> Beyond that, I'm curious about the choice to implement this as a new
>>> service.  I definitely agree that this is not something that should be
>>> implemented inside of Nova.  However, I wonder if it makes sense as a
>>> feature in Heat.  It seems like an orchestration feature.
>>>
>>> Thoughts?
>>
>> This is a workflow (not orchestration) feature and would be solidly in-scope for a WFaaS API (e.g. the proposed https://wiki.openstack.org/wiki/Convection mentioned several times in this thread) in the form of a much more generic "cloud cron" type feature.
>>
>> It certainly *could* be implemented in either Heat or Horizon, but there are pretty strong arguments for not doing so. We already have one example - Autoscaling - of something like this being too-tightly coupled into Heat, and we have a bunch of work ahead to try to tease the two apart so that everybody can get the benefits of Autoscaling, not just Heat template users. I wouldn't be in favour of creating another situation like that at this stage.
>>
>> cheers,
>> Zane.
> 
> Thanks for saying what I meant much more clearly :)  The piece where we are performing the actual snapshot is definitely a workflow (try to (optionally) pause a server, create snapshot, if its stalled, restart (or not), etc).

Cool, this all makes sense to me now and I agree.

> The part I'm still struggling with is whether or not the actual setting the cron time itself makes sense in a WFaaS API.  It could make sense to execute a workflow based on when a cron service says to kick it off instead.  It doesn't matter too much to me, I just don't want to conflate things too much.

In any case, I don't see this as something triggered through the base
compute API in Nova.

-- 
Russell Bryant