Open Stack

On 15/04/14 06:16, Qiming Teng wrote:
> 3) Can/should we do the VM HA orchestration in Heat?
>
> My perception is that it can be done in Heat, based on my limited
> understandig of how Heat works.  It may imply some requirements to other
> projects (e.g.  nova, cinder, neutron ...) as well, though Heat should be
> the orchestrator.
>
> What do we need then?
>
>    - A resource type for VM groups/clusters, for the redundant
>      provisioning.  VMs in the group can be identical instances, managed
>      by a Pacemaker setup among the VMs, just like a WatchRule in Heat can
>      be controlled by Ceilometer.

Heat is not a catch-all place to put features that need co-ordination 
amongst projects; Heat provides a declarative way of interacting with 
existing OpenStack APIs. So if you have another OpenStack API for VM 
groups/clusters we can add a resource type to talk to it.

All of the cases where we have attempted to implement missing parts of 
OpenStack (autoscaling, HARestarter) directly in Heat have turned out to 
be giant headaches. We have a lot of work still ahead to split 
autoscaling out of the Heat engine and give it its own API. 
HARestarter's days, as Steve mentioned, are numbered. I'd like to avoid 
taking any similar shortcuts in future.

cheers,
Zane.