Re: [netmod] yang-data-ext issues

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

Return-Path: <j.schoenwaelder@jacobs-university.de>
X-Original-To: netmod@ietfa.amsl.com
Delivered-To: netmod@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 94CFF124F57 for <netmod@ietfa.amsl.com>; Mon, 23 Apr 2018 10:36:40 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.9
X-Spam-Level:
X-Spam-Status: No, score=-1.9 tagged_above=-999 required=5 tests=[BAYES_00=-1.9] autolearn=ham autolearn_force=no
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id e3s8ZW7LEPsc for <netmod@ietfa.amsl.com>; Mon, 23 Apr 2018 10:36:39 -0700 (PDT)
Received: from atlas5.jacobs-university.de (atlas5.jacobs-university.de [212.201.44.20]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id DAD0F1242F7 for <netmod@ietf.org>; Mon, 23 Apr 2018 10:36:38 -0700 (PDT)
Received: from localhost (demetrius5.irc-it.jacobs-university.de [10.70.0.222]) by atlas5.jacobs-university.de (Postfix) with ESMTP id ABF41D00; Mon, 23 Apr 2018 19:36:37 +0200 (CEST)
X-Virus-Scanned: amavisd-new at jacobs-university.de
Received: from atlas5.jacobs-university.de ([10.70.0.217]) by localhost (demetrius5.jacobs-university.de [10.70.0.222]) (amavisd-new, port 10032) with ESMTP id UMLvO7V2LSDD; Mon, 23 Apr 2018 19:36:37 +0200 (CEST)
Received: from hermes.jacobs-university.de (hermes.jacobs-university.de [212.201.44.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "hermes.jacobs-university.de", Issuer "Jacobs University CA - G01" (verified OK)) by atlas5.jacobs-university.de (Postfix) with ESMTPS; Mon, 23 Apr 2018 19:36:37 +0200 (CEST)
Received: from localhost (demetrius3.jacobs-university.de [212.201.44.48]) by hermes.jacobs-university.de (Postfix) with ESMTP id 66D7420035; Mon, 23 Apr 2018 19:36:37 +0200 (CEST)
X-Virus-Scanned: amavisd-new at jacobs-university.de
Received: from hermes.jacobs-university.de ([212.201.44.23]) by localhost (demetrius3.jacobs-university.de [212.201.44.32]) (amavisd-new, port 10024) with ESMTP id OPVLyndmCWtZ; Mon, 23 Apr 2018 19:36:37 +0200 (CEST)
Received: from elstar.local (unknown [10.50.231.133]) by hermes.jacobs-university.de (Postfix) with ESMTP id 078CB20031; Mon, 23 Apr 2018 19:36:37 +0200 (CEST)
Received: by elstar.local (Postfix, from userid 501) id D8F0242BD9BC; Mon, 23 Apr 2018 19:36:36 +0200 (CEST)
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
Message-ID: <20180423173636.fx63befibcc4vhmh@elstar.local>
Reply-To: Juergen Schoenwaelder <j.schoenwaelder@jacobs-university.de>
Mail-Followup-To: Robert Varga <nite@hq.sk>, Ladislav Lhotka <lhotka@nic.cz>, netmod@ietf.org
References: <20180416.145617.1262098657698751846.mbj@tail-f.com> <87h8oal7iu.fsf@nic.cz> <a7d3702d-1406-7bd2-caf6-7c07812c86aa@hq.sk> <6d5cd4e4257822e4a5c478dc934c5433428aff38.camel@nic.cz> <20180423165104.zi7g75tifhekmezh@elstar.local> <ecb9cc29-67c5-df8f-8a37-140733e0c1e7@hq.sk>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <ecb9cc29-67c5-df8f-8a37-140733e0c1e7@hq.sk>
User-Agent: NeoMutt/20171215
Archived-At: <https://mailarchive.ietf.org/arch/msg/netmod/iBJvdSG55CbvUw3R-rayALfxbOE>
Subject: Re: [netmod] yang-data-ext issues
X-BeenThere: netmod@ietf.org
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: NETMOD WG list <netmod.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/netmod>, <mailto:netmod-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/netmod/>
List-Post: <mailto:netmod@ietf.org>
List-Help: <mailto:netmod-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/netmod>, <mailto:netmod-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 23 Apr 2018 17:36:40 -0000

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/>