Re: [core] CBOR Encoding of Data Modeled with YANG

Juergen Schoenwaelder <j.schoenwaelder@jacobs-university.de> Wed, 09 December 2015 18:45 UTC

Return-Path: <j.schoenwaelder@jacobs-university.de>
X-Original-To: core@ietfa.amsl.com
Delivered-To: core@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 413081B2C58 for <core@ietfa.amsl.com>; Wed, 9 Dec 2015 10:45:28 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -3.86
X-Spam-Level:
X-Spam-Status: No, score=-3.86 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, HELO_EQ_DE=0.35, RCVD_IN_DNSWL_MED=-2.3, T_RP_MATCHES_RCVD=-0.01] autolearn=ham
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 IcqYRx6PcR8Z for <core@ietfa.amsl.com>; Wed, 9 Dec 2015 10:45:26 -0800 (PST)
Received: from atlas3.jacobs-university.de (atlas3.jacobs-university.de [212.201.44.18]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id D41DE1A1A11 for <core@ietf.org>; Wed, 9 Dec 2015 10:45:25 -0800 (PST)
Received: from localhost (demetrius5.irc-it.jacobs-university.de [10.70.0.222]) by atlas3.jacobs-university.de (Postfix) with ESMTP id 0A9728FE; Wed, 9 Dec 2015 19:45:24 +0100 (CET)
X-Virus-Scanned: amavisd-new at jacobs-university.de
Received: from atlas3.jacobs-university.de ([10.70.0.220]) by localhost (demetrius5.jacobs-university.de [10.70.0.222]) (amavisd-new, port 10030) with ESMTP id Tn181IZ8Nqfh; Wed, 9 Dec 2015 19:45:23 +0100 (CET)
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 atlas3.jacobs-university.de (Postfix) with ESMTPS; Wed, 9 Dec 2015 19:45:23 +0100 (CET)
Received: from localhost (demetrius2.jacobs-university.de [212.201.44.47]) by hermes.jacobs-university.de (Postfix) with ESMTP id E805D20055; Wed, 9 Dec 2015 19:45:22 +0100 (CET)
X-Virus-Scanned: amavisd-new at jacobs-university.de
Received: from hermes.jacobs-university.de ([212.201.44.23]) by localhost (demetrius2.jacobs-university.de [212.201.44.32]) (amavisd-new, port 10024) with ESMTP id sENVj4FNJ7wj; Wed, 9 Dec 2015 19:45:22 +0100 (CET)
Received: from elstar.local (elstar.jacobs.jacobs-university.de [10.50.231.133]) by hermes.jacobs-university.de (Postfix) with ESMTP id BE2D620054; Wed, 9 Dec 2015 19:45:21 +0100 (CET)
Received: by elstar.local (Postfix, from userid 501) id 0DF31392AEB3; Wed, 9 Dec 2015 19:45:20 +0100 (CET)
Date: Wed, 09 Dec 2015 19:45:20 +0100
From: Juergen Schoenwaelder <j.schoenwaelder@jacobs-university.de>
To: Michel Veillette <Michel.Veillette@trilliantinc.com>
Message-ID: <20151209184520.GB24514@elstar.local>
Mail-Followup-To: Michel Veillette <Michel.Veillette@trilliantinc.com>, Ladislav Lhotka <lhotka@nic.cz>, "core@ietf.org" <core@ietf.org>
References: <20151207194229.GA61491@elstar.local> <BLUPR06MB1763B7F9EBF812C06DB04252FE090@BLUPR06MB1763.namprd06.prod.outlook.com> <20151207203826.GA61647@elstar.local> <BLUPR06MB1763E9AB0D1E4A0478D47C05FE090@BLUPR06MB1763.namprd06.prod.outlook.com> <20151208093350.GA62650@elstar.local> <5666AE1A.2040908@ackl.io> <m28u55lz0g.fsf@birdie.labs.nic.cz> <BLUPR06MB1763F77EC35C38FE64265C73FE080@BLUPR06MB1763.namprd06.prod.outlook.com> <m2io48ox1m.fsf@birdie.labs.nic.cz> <BLUPR06MB17639FD1577077587EC75CBBFEE80@BLUPR06MB1763.namprd06.prod.outlook.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="iso-8859-1"
Content-Disposition: inline
X-Clacks-Overhead: GNU Terry Pratchett
Content-Transfer-Encoding: 8bit
In-Reply-To: <BLUPR06MB17639FD1577077587EC75CBBFEE80@BLUPR06MB1763.namprd06.prod.outlook.com>
User-Agent: Mutt/1.4.2.3i
Archived-At: <http://mailarchive.ietf.org/arch/msg/core/Xv06iD89rIr65g7r6WT1RL4XHiM>
Cc: "core@ietf.org" <core@ietf.org>
Subject: Re: [core] CBOR Encoding of Data Modeled with YANG
X-BeenThere: core@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
Reply-To: Juergen Schoenwaelder <j.schoenwaelder@jacobs-university.de>
List-Id: "Constrained RESTful Environments \(CoRE\) Working Group list" <core.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/core>, <mailto:core-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/core/>
List-Post: <mailto:core@ietf.org>
List-Help: <mailto:core-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/core>, <mailto:core-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 09 Dec 2015 18:45:28 -0000

On Wed, Dec 09, 2015 at 06:20:26PM +0000, Michel Veillette wrote:
> 
> ยท        import without revision will be rejected
> The list of data nodes must be known and can't change over time to make the algorithm unambiguous.
> In this context, import of modules without revision can't be supported.
>

Almost all published YANG modules so far use import without revision...

I am also concerned tracking all revisions in order to produce the
correct numbers in not very robust. I have seen proprietary MIB
modules with revisions in the hundreds and if it is necessary to
obtain all revisions in order to compute node ids, this will be a
major hurdle in practice. Well, in the IoT space, perhaps we end up
only with revisions in the 20s or 30s but again obtaining all
revisions to get the numbers will be painful. And since humans are
involved, there is also a change for subtle errors that are difficult
to spot.

/js

PS: We had some discussion about the auto-numbering of enum and bits
    values in YANG 1.1. Automatic numbering algorithms are subtle.

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