Merge lp://qastaging/~cerberus/nova/lp820658 into lp://qastaging/~hudson-openstack/nova/trunk

Generally seems fine, but now the host filters should have their instance_type_to_filter() methods renamed to request_spec_to_filter().

Should the span_zones flag be part of the request spec or should it just be a boolean param on select()? I think I prefer the latter?

whoops, should be ...

Updated with sandy's changes. Talked him out of making the latter change on the grounds that the request_spec represents the entire context for the desired results, and that attaching an additional parameter external to that context is confusing.

s/talked him out of/bribed with beer/

Does/can this branch address this as well: https://bugs.launchpad.net/nova/+bug/821252

@Brian: I don't believe so, as this is only a fix for the HostFilter scheduler, and even then, only forces the scheduler to ignore the host that the instance is already on. The rationale being that we need to do a lot more work to actually get the schedulers to a point where they're intelligent about choosing a destination by instance_type, so this is just the first stage in getting resize to work a bit more consistently.

If you were to go with the LeastCostScheduler, which doesn't let you specify the filter currently, then it wouldn't buy you anything. With that said, we could of course adapt any of the schedulers to work.

Okay, I just wanted to check that we couldn't hit two birds with one stone, here.

I'm not very up to speed on schedulers, so please correct me if I'm wrong: would it make sense to implement this as just a HostExclusionFilter and use that in conjunction with an InstanceTypeFilter when needed?

Brian, it's not currently possible to stack filters WSGI-style. Take a gander at the "choose_host_filter" method in host_filter.py. It instantiates the first filter it finds based on the name requested. I think that sounds like a pretty good use-case, but I'd rather we file a blueprint or bug for implementing that rather than trying to shoehorn that functionality in this patch.

Does that work for you?

I agree with dietz. That's not in the realm of a bugfix, that's blueprint world!

161 + _, query = host_filter.request_spec_to_filter(request_spec)

not a fan of _

would it make sense to have span_zones=True in the request spec in the test?

Attempt to merge into lp:nova failed due to conflicts:

text conflict in nova/scheduler/host_filter.py