openstack team mailing list archive

[Michael Still <michael.still@xxxxxxxxxxxxx>]

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