*What it means
	* Testing multiple services at different versions
		* Example: keystone, glance, cinder, neutron on $proposed, nova on $stable
	* Testing multiple components within a service at different versions
		* Example: nova-compute on $stable, nova-* on $proposed

*What nova needs
	* At first, running a full devstack with everything on $proposed, but with nova-compute on $stable
	* Later, old schema, new conductor, old compute
	* Later, potentially running more components on $stable, but that is less important
	* Eventually, a multi-node test where one compute is new and one compute is on $stable, for testing instance migrations

*Concerns
	* How do we handle requirements differences between old and new if we are trying to run old and new
	* How does this impact distro story of this environment (where package dependencies are also needed)?

*Proposals
	* Something new that hacks up devstack mid/post stream
		* Pro: probably the quickest thing to get _some_ sort of coverage, maybe experimental job initially?
		* Con: new infrastructure, new things to maintain, etc
	* Make grenade able to do this - sorting out old / new trees is hard, we solved it here. Run with it.
		* Pro: Leverage existing stuff, maybe provides a more realistic scenario
		* Con: Requires hacking up grenade. Deploying devstack, then upgrade, then restart devstack will (I think) take longer to run than we really need for just the hack above.
	* TripleO CD-based environments for testing
		* Pro: This is the right/best/most-complete way to do it
		* Con: Probably a little far off for what we need in the immediate verification step (but maybe not)

*Directions for mismatched services in the Gate
Target: Icehouse-1
Owner: Joe
	* stable/havana -> master + zuul_refs
		* new database + new conductor + old compute - #1
		* old database + new conductor + old compute - #2
	* stable/havana + zuul_refs -> master
		* same as above

*Todos:
	* Global venv support for devstack - Monty is 95% of the way there

Discussion on irc about keystoneclient testing, would like to test - verities change to keystoneclient is backwards compatible
   keystoneclient - proposed, keystoneclient - n-1, keystoneclient - n-2
   - different tempest jobs? - 90% of the way there from Monty