openstack team mailing list archive

[Mark McLoughlin <markmc@xxxxxxxxxx>]

On Tue, 2012-01-03 at 19:54 +0000, Ewan Mellor wrote:
> I'd love to see openstack-common get off the ground, so I'm all in
> favor of this.
> 
> One question: why do you feel that you need such strong backwards
> compatibility?  If someone makes a change in openstack-common and
> makes simultaneous changes in all OpenStack projects to match, isn’t
> that sufficient?

No, I really don't think it is sufficient. Unless we want packagers to
hunt us down with sharp implements :)

Each of the projects are separated by an API which we maintain some
compatibility around. So, in theory, you can use e.g. Essex Glance with
Diablo Nova. If you make it so that Glance requires Essex Common and
doesn't work with Diablo Common, but Nova requires Diablo Common and
doesn't work with Essex common ... you're screwed.

This may not sound like much of a practical concern, but it's exactly
why packagers curse the Java and Ruby worlds for their sloppiness. It's
really painful.

And, IMHO, if we allow it to happen, it will be an even bigger problem
with the APIs in openstack-common than the inter-project APIs.

Cheers,
Mark.