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

Juergen Schoenwaelder <j.schoenwaelder@jacobs-university.de> Sat, 21 July 2018 05:49 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 419E4130E1E for <netmod@ietfa.amsl.com>; Fri, 20 Jul 2018 22:49:39 -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 58znHJngKW_U for <netmod@ietfa.amsl.com>; Fri, 20 Jul 2018 22:49:37 -0700 (PDT)
Received: from anna.localdomain (anna.eecs.jacobs-university.de [IPv6:2001:638:709:5::7]) by ietfa.amsl.com (Postfix) with ESMTP id 1A7AD12D949 for <netmod@ietf.org>; Fri, 20 Jul 2018 22:49:37 -0700 (PDT)
Received: by anna.localdomain (Postfix, from userid 501) id 795DB2362544; Sat, 21 Jul 2018 07:49:35 +0200 (CEST)
Date: Sat, 21 Jul 2018 07:49:35 +0200
From: Juergen Schoenwaelder <j.schoenwaelder@jacobs-university.de>
To: Andy Bierman <andy@yumaworks.com>
Cc: NetMod WG <netmod@ietf.org>
Message-ID: <20180721054935.cgsgpxvnkmnpro6n@anna.jacobs.jacobs-university.de>
Reply-To: Juergen Schoenwaelder <j.schoenwaelder@jacobs-university.de>
Mail-Followup-To: Andy Bierman <andy@yumaworks.com>, NetMod WG <netmod@ietf.org>
References: <CABCOCHQ47ztJTPaZMZK7FWHsRPk1jN6SuuAWtg08rmtVgUPEWw@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: inline
In-Reply-To: <CABCOCHQ47ztJTPaZMZK7FWHsRPk1jN6SuuAWtg08rmtVgUPEWw@mail.gmail.com>
User-Agent: NeoMutt/20180622
Archived-At: <https://mailarchive.ietf.org/arch/msg/netmod/KoEjPdOl9olZgjhMvlDbLVJoH6c>
Subject: Re: [netmod] backward compatibility requirements in draft-verdt-netmod-yang-versioning-reqs-00
X-BeenThere: netmod@ietf.org
X-Mailman-Version: 2.1.27
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: Sat, 21 Jul 2018 05:49:39 -0000

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.

/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/>