[openstack-dev] [Nova] Some thoughts on API microversions

Chris Friesen chris.friesen at windriver.com
Thu Aug 4 17:17:07 UTC 2016

On 08/04/2016 09:28 AM, Edward Leafe wrote:

> The idea that by specifying a distinct microversion would somehow guarantee
> an immutable behavior, though, is simply not the case. We discussed this at
> length at the midcycle regarding the dropping of the nova-network code; once
> that's dropped, there won't be any way to get that behavior no matter what
> microversion you specify. It's gone. We signal this with deprecation notices,
> release notes, etc., and it's up to individuals to move away from using that
> behavior during this deprecation period. A new microversion will never help
> anyone who doesn't follow these signals.

I was unable to attend the midcycle, but that seems to violate the original 
description of how microversions were supposed to work.  As I recall, the 
original intent was something like this:

At time T, we remove an API via microversion X.  We keep the code around to 
support it when using microversions less than X.

At some later time T+i, we bump the minimum microversion up to X.  At this point 
nobody can ever request the older microversions, so we can safely remove the 
server-side code.

Have we given up on this?  Or is nova-network a special-case?


More information about the OpenStack-dev mailing list