Re: [netmod] yang-data-ext issues

Juergen Schoenwaelder <j.schoenwaelder@jacobs-university.de> Mon, 23 April 2018 17:36 UTC

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Date: Mon, 23 Apr 2018 19:36:36 +0200
From: Juergen Schoenwaelder <j.schoenwaelder@jacobs-university.de>
To: Robert Varga <nite@hq.sk>
Cc: Ladislav Lhotka <lhotka@nic.cz>, netmod@ietf.org
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Subject: Re: [netmod] yang-data-ext issues
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On Mon, Apr 23, 2018 at 07:18:38PM +0200, Robert Varga wrote:
> On 23/04/18 18:51, Juergen Schoenwaelder wrote:
> > Some people will say that the cost of a new language version is high.
> > (Well, when we did 1.1, some people said it will never be deployed.)
> > Anyway, not bumping the YANG version number but having instead several
> > (optional) language extensions is just hiding the version number
> > change under the carpet.
> 
> Not quite, as extensions allow for modular/incremental evolution, as an
> implementer I do not have to go through a long development cycle where I
> need to rewire language aspects just to get the features my users need
> for their models...

Once we standardize extensions (and this is what I am talking about),
we better make sure that the whole stays consistent. Otherwise, we
will end up with patchwork where all the patches may work in isolation
but sooner or later they will fall apart when you look at all the
possible combinations.

I am in favour of managing a clean definition of the core of the YANG
language instead of creating patchwork. It is great if people create
and prototype new extensions but once such extensions are considered
to be ready for general use, we should roll them into the core (and
remove any cruft from the core at the same time).

/js

-- 
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/>