Alternatively, we could just consider the ec2 mapping layer to be global data that must be replicated somehow across the system. I don't think we can really ensure no collisions mapping from uuid -> ec2_id deterministically, and I don't see a clear path forward when we do get a collision.
Vish On May 8, 2012, at 12:24 AM, Michael Still wrote: > On 04/05/12 20:31, Eoghan Glynn wrote: > > Sorry for the slow reply, I've been trapped in meetings. > > [snip] > >> So the way things currently stand, the EC2 image ID isn't really capable of >> migration. >> >> I was thinking however that we should change the EC2 image generation logic, >> so that there is a reproducible glance UUID -> EC2 mapping (with a small >> chance of collision). This change would allow the same EC2 ID to be generated >> in multiple regions for a given glance UUID (modulo collisions). >> >> Would that be helpful in your migration use-case? > > I do think this is a good idea. Or even if the column wasn't > auto-increment, but just picked a random number or something (because > that would be marginally less likely to clash). Without somehow making > these ec2 ids more global, replication between regions is going to > suffer from ec2 api users having to somehow perform a lookup out of band. > > Now, my use case is a bit special, because I can enforce that images are > only ever uploaded to one master region, and then copied to all others. > I think that's probably not true for other users though. > > Mikal > > _______________________________________________ > Mailing list: https://launchpad.net/~openstack > Post to : openstack@lists.launchpad.net > Unsubscribe : https://launchpad.net/~openstack > More help : https://help.launchpad.net/ListHelp _______________________________________________ Mailing list: https://launchpad.net/~openstack Post to : openstack@lists.launchpad.net Unsubscribe : https://launchpad.net/~openstack More help : https://help.launchpad.net/ListHelp