[Openstack] Instance IDs and Multiple Zones
eday at oddments.org
Thu Mar 24 00:03:05 UTC 2011
On Wed, Mar 23, 2011 at 11:09:01PM +0000, Sandy Walsh wrote:
> From: Ewan Mellor [Ewan.Mellor at eu.citrix.com]
> > To your point about the boundary of preservation of ID, that's a good question. If you ignore the security / trust issues, then the obvious answer is that IDs should be globally, infinitely, permanently unique. That's what UUIDs are for. We can generate these randomly without any need for a central authority, and with no fear of collisions. It would certainly be nice if my VM can leave my SoftLayer DC and arrive in my Rackspace DC and when it comes back I still know that it's the same VM. That's the OpenStack dream, right?
> Hmm, I may have been swayed against UNC. Routing and caching can still be layered on a UUID without having to parse it.
"If you ignore the security / trust issues..." but we can't ignore
them, so UUIDs alone are sufficient. Do we want this namespace per
zone, deployment, resource owner, or some other dimension?
I see the cases against per-zone with RHEL licensing, but pvo does
give an acceptable workaround. Besides that, I guess I don't see the
value in permanent instances. Tools, billing, etc. should work with a
changing working set. Having said that, I'd be ok with any of those as
namespace boundaries (although auth/owner gets nasty with federation),
as long as we have *something*.
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