Re: [netmod] backward compatibility requirements in draft-verdt-netmod-yang-versioning-reqs-00

Andy Bierman <andy@yumaworks.com> Sat, 21 July 2018 08:48 UTC

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From: Andy Bierman <andy@yumaworks.com>
Date: Sat, 21 Jul 2018 01:48:37 -0700
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To: Juergen Schoenwaelder <j.schoenwaelder@jacobs-university.de>, Andy Bierman <andy@yumaworks.com>, NetMod WG <netmod@ietf.org>
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Subject: Re: [netmod] backward compatibility requirements in draft-verdt-netmod-yang-versioning-reqs-00
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On Fri, Jul 20, 2018 at 10:49 PM, Juergen Schoenwaelder <
j.schoenwaelder@jacobs-university.de>; wrote:

> On Fri, Jul 20, 2018 at 02:41:33PM -0700, Andy Bierman wrote:
> > Hi,
> >
> > I strongly object to requirement 3.1:
> >
> >
> >     3.1  The solution MUST provide a mechanism to allow servers to
> >             support existing clients in a backward compatible way.
> >
> >
> >
> > This is not what servers do today at all.
> > They provide only one version of an implemented module, as specified in
> RFC
> > 7950.
>
> But today a backwards incompatible change leads to a new module and
> you can very well implement two modules if that is reasonable to do in
> order to allow clients a transition period.
>


But you can tell the 2 subtrees apart this way.
If I change /foo from a container to a list, then how do you support both
implementations
of container /foo and list /foo at the same time?



>
> /js
>

Andy


>
> --
> Juergen Schoenwaelder           Jacobs University Bremen gGmbH
> Phone: +49 421 200 3587         Campus Ring 1 | 28759 Bremen | Germany
> Fax:   +49 421 200 3103         <https://www.jacobs-university.de/>
>