Re: [netmod] schema mount and YANG library

Lou Berger <lberger@labn.net> Tue, 16 January 2018 14:24 UTC

Return-Path: <lberger@labn.net>
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 00CD61314EA for <netmod@ietfa.amsl.com>; Tue, 16 Jan 2018 06:24:54 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.902
X-Spam-Level:
X-Spam-Status: No, score=-1.902 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (768-bit key) header.d=labn.net
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 qddPg3JWQk94 for <netmod@ietfa.amsl.com>; Tue, 16 Jan 2018 06:24:52 -0800 (PST)
Received: from gproxy10-pub.mail.unifiedlayer.com (gproxy10-pub.mail.unifiedlayer.com [69.89.20.226]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 0C9271314F4 for <netmod@ietf.org>; Tue, 16 Jan 2018 06:24:42 -0800 (PST)
Received: from cmgw2 (unknown [10.0.90.83]) by gproxy10.mail.unifiedlayer.com (Postfix) with ESMTP id C93BF140568 for <netmod@ietf.org>; Tue, 16 Jan 2018 07:24:40 -0700 (MST)
Received: from box313.bluehost.com ([69.89.31.113]) by cmgw2 with id z2Qd1w0072SSUrH012QgUi; Tue, 16 Jan 2018 07:24:40 -0700
X-Authority-Analysis: v=2.2 cv=doKrMxo4 c=1 sm=1 tr=0 a=h1BC+oY+fLhyFmnTBx92Jg==:117 a=h1BC+oY+fLhyFmnTBx92Jg==:17 a=IkcTkHD0fZMA:10 a=xqWC_Br6kY4A:10 a=RgaUWeydRksA:10 a=wU2YTnxGAAAA:8 a=u07AKapRAAAA:8 a=48vgC7mUAAAA:8 a=3W2mLpD6AtZF7ffR4YQA:9 a=QEXdDO2ut3YA:10 a=ZVvG44Nqbz4A:10 a=aztA8ZntzogA:10 a=Yz9wTY_ffGCQnEDHKrcv:22 a=SkebfZ6J2Mmvk2rLHZle:22 a=w1C3t2QeGrPiZgrLijVG:22
DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=labn.net; s=default; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:MIME-Version :Date:Message-ID:From:References:Cc:To:Subject:Sender:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=V5S/j2ScnKF9eFZKRGKdylEE+u5g4sQyATv54WDAKxc=; b=vVCbHb49eMcZfv8XlN9yXrM1Sy kmI1XhbwfWwdw9CJljkSFrfnFzCMIoQbvQdyCIvhd8Co5aI+M7fEGkql0uB9aCi8GIkU4eo4HKpry GJtjZ1e6TTJDHssDfObG7AnMa;
Received: from pool-100-15-86-101.washdc.fios.verizon.net ([100.15.86.101]:44360 helo=[IPv6:::1]) by box313.bluehost.com with esmtpsa (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.89) (envelope-from <lberger@labn.net>) id 1ebSAG-003iII-Ra; Tue, 16 Jan 2018 07:24:36 -0700
To: Martin Bjorklund <mbj@tail-f.com>
Cc: lhotka@nic.cz, netmod@ietf.org
References: <160feef5550.27d3.9b4188e636579690ba6c69f2c8a0f1fd@labn.net> <20180116.142407.1498790690296330642.mbj@tail-f.com> <160ff28ef68.27d3.9b4188e636579690ba6c69f2c8a0f1fd@labn.net> <20180116.145003.1110791592584714461.mbj@tail-f.com>
From: Lou Berger <lberger@labn.net>
Message-ID: <53c046c7-bd41-4a4b-ef61-0d3bf9414269@labn.net>
Date: Tue, 16 Jan 2018 09:24:35 -0500
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.5.2
MIME-Version: 1.0
In-Reply-To: <20180116.145003.1110791592584714461.mbj@tail-f.com>
Content-Type: text/plain; charset="utf-8"; format="flowed"
Content-Transfer-Encoding: 8bit
Content-Language: en-US
X-AntiAbuse: This header was added to track abuse, please include it with any abuse report
X-AntiAbuse: Primary Hostname - box313.bluehost.com
X-AntiAbuse: Original Domain - ietf.org
X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12]
X-AntiAbuse: Sender Address Domain - labn.net
X-BWhitelist: no
X-Source-IP: 100.15.86.101
X-Exim-ID: 1ebSAG-003iII-Ra
X-Source:
X-Source-Args:
X-Source-Dir:
X-Source-Sender: pool-100-15-86-101.washdc.fios.verizon.net ([IPv6:::1]) [100.15.86.101]:44360
X-Source-Auth: lberger@labn.net
X-Email-Count: 7
X-Source-Cap: bGFibm1vYmk7bGFibm1vYmk7Ym94MzEzLmJsdWVob3N0LmNvbQ==
X-Local-Domain: yes
Archived-At: <https://mailarchive.ietf.org/arch/msg/netmod/rVSA8sPkV2ObERLIJnSpxW7RNYM>
Subject: Re: [netmod] schema mount and YANG library
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: Tue, 16 Jan 2018 14:24:54 -0000


On 1/16/2018 8:50 AM, Martin Bjorklund wrote:
> Lou Berger <lberger@labn.net> wrote:
>>
>> On January 16, 2018 8:24:42 AM Martin Bjorklund <mbj@tail-f.com>
>> wrote:
>>
>>> Lou Berger <lberger@labn.net> wrote:
>>>> Lada,
>>>>
>>>>
>>>> On January 16, 2018 7:07:15 AM Ladislav Lhotka <lhotka@nic.cz> wrote:
>>>>
>>>>> On Tue, 2018-01-16 at 06:30 -0500, Lou Berger wrote:
>>>>>> Lada,
>>>>>>
>>>>>> It sounds like you are proposing in (1) a fairly significant change in
>>>>>> the
>>>>>> direction of the draft and in (2) a basic approach that has been
>>>>> It is no change in direction, just a simplification of the
>>>>> schema-describing
>>>>> state data. Given the recent developments in 7895bis it makes no sense
>>>>> to me to
>>>>> have two "schema" lists if we can have just one.
>>>>>
>>>> Managing transition is hard. It's also highlights why Yang Library
>>>> this needs to be at least equally discussed in this group.
>>>>
>>>> I will talk with my co-chairs and perhaps the ADs to get their opinion
>>>> on making such a change this point in the process.
>>>>
>>>>
>>>>>> rejectected by the WG multiple times.  FWIW there are drafts already
>>>>>> with
>>>>> No at all. The first and last time I proposed this was on 15 December
>>>>> 2017:
>>>>>
>>>>> https://www.ietf.org/mail-archive/web/netmod/current/msg19753.html
>>>>>
>>>> Oh, I certainly would call you proposing that the schema for inline be
>>>> part of the rest of the schema Mount module well before that. I'm sure
>>>> I can dig up mail / slides it really necessary...
>>> I don't think this has been proposed before.  All previous proposals
>>> were basically variants on what is now "use-schema", which works fine
>>> when all instances have the same schema.  This new proposal solves the
>>> issue with different schemas in different instances.
>>>
>> I thought the previous proposals that as well, so don't see material
>> difference - at least from the usage standpoint. I also don't see why
>> the previous arguments that resulted in consensus for using Yang
>> Library underneath the an in line Mount Point don't apply.
> B/c it doesn't work well with the NMDA.  You can't mount yang library
> in the configuration datastores; it has to be mounted in operational.
> With meta-data, you can actually report the correct schema even in
> running.  (This is actually true also for pre-NMDA systems).
>
Understood and agree there is nothing new here and the current version 
of SM (including inline) has the same limitation as rfc7895, and I'd 
expect it to behave the same once we have rfc7985bis -- in fact the 
inline case "just works" with YL-bis as defined today.

The argument I recall being the key point on inline was handling the 
large variety of possible different implementation approaches for 
modules using inline.  For example an LNE that is implemented using VMs 
which can be managed by the host at different times of the VMs 
operational life cycle based on customer/provider requirements.  I 
really don't see how YL-bis has any bearing on this point and I think it 
is incumbent upon those revisiting past/closed WG decisions (in this 
case, inline schema being represented by YL) to argue why the decision 
needs to be revisited.

Lou

> /martin
>