Open Stack

On 23/06/14 19:25, Clint Byrum wrote:
> Hello! I would like to turn your attention to this specification draft
> that I've written:
>
> https://review.openstack.org/#/c/100012/1/specs/convergence-continuous-observer.rst
>
> Angus has suggested that perhaps Ceilometer is a better place to handle
> this. Can you please comment on the review, or can we have a brief
> mailing list discussion about how best to filter notifications?
>
> Basically in Heat when a user boots an instance, we would like to act as
> soon as it is active, and not have to poll the nova API to know when
> that is. Angus has suggested that perhaps we can just tell ceilometer to
> hit Heat with a web hook when that happens.

I'm all in favour of having Ceilometer filter the firehose for us if we 
can :)

Webhooks would seem to add a lot of overhead though (set up + tear down 
a connection for every notification), that could perhaps be avoided by 
using a message bus? Given that both setting up and receiving these 
notifications would be admin-only operations, is there any benefit to 
handling them through a webhook API rather than through oslo.messaging?

cheers,
Zane.