Open Stack

On 10/29/2013 03:14 PM, Andrew Laski wrote:

> Having Nova call into Heat is backwards IMO.

Agreed.

>  If there are specific
> pieces of information that Nova can expose, or API capabilities to help
> with orchestration/placement that Heat or some other service would like
> to use then let's look at that.

Agreed.

 > Nova has placement concerns that extend
> to finding a capable hypervisor for the VM that someone would like to
> boot, and then just slightly beyond.  If there are higher level
> decisions to be made about placement decisions I think that belongs
> outside of Nova, and then just tell Nova where to put it.

Not sure about this part.  I think that with instance groups Nova should 
be aware of the placement of the group as a whole, not just single 
instances.

As soon as we start trying to do placement logic outside of Nova it 
becomes trickier to deal with race conditions when competing against 
other API users trying to acquire resources at the same time.

Chris