Open Stack

On 02/24/2014 05:01 PM, Morgan Fainberg wrote:
> On the topic of backwards incompatible changes:
> 
> I strongly believe that breaking current clients that use the APIs
> directly is the worst option possible. All the arguments about needing
> to know which APIs work based upon which backend drivers are used are
> all valid, but making an API incompatible change when we’ve made the
> contract that the current API will be stable is a very bad approach.
> Breaking current clients isn’t just breaking “novaclient", it would also
> break any customers that are developing directly against the API. In the
> case of cloud deployments with real-world production loads on them (and
> custom development around the APIs) upgrading between major versions is
> already difficult to orchestrate (timing, approvals, etc), if we add in
> the need to re-work large swaths of code due to API changes, it will
> become even more onerous and perhaps drive deployers to forego the
> upgrades in lieu of stability.
> 
> If the perception is that we don’t have stable APIs (especially when we
> are ostensibly versioning them), driving adoption of OpenStack becomes
> significantly more difficult. Difficulty in driving further adoption
> would be a big negative to both the project and the community.
> 
> TL;DR, “don’t break the contract”. If we are seriously making
> incompatible changes (and we will be regardless of the direction) the
> only reasonable option is a new major version.

FWIW, I do *not* consider non backwards compatible changes to be on the
table for the existing API.  Evolving it would have to be done in a
backwards compatible way.  I'm completely in agreement with that.

-- 
Russell Bryant