Re: [netmod] [Netconf] Alternative YANG library structure for 7895bis

Andy Bierman <andy@yumaworks.com> Mon, 11 December 2017 20:55 UTC

Return-Path: <andy@yumaworks.com>
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 1ACD61289B0 for <netmod@ietfa.amsl.com>; Mon, 11 Dec 2017 12:55:41 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.6
X-Spam-Level:
X-Spam-Status: No, score=-2.6 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_LOW=-0.7, SPF_PASS=-0.001] autolearn=unavailable autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=yumaworks-com.20150623.gappssmtp.com
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 WN98LbGB2XKV for <netmod@ietfa.amsl.com>; Mon, 11 Dec 2017 12:55:35 -0800 (PST)
Received: from mail-lf0-x22e.google.com (mail-lf0-x22e.google.com [IPv6:2a00:1450:4010:c07::22e]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 0985D1289B5 for <netmod@ietf.org>; Mon, 11 Dec 2017 12:55:32 -0800 (PST)
Received: by mail-lf0-x22e.google.com with SMTP id j124so20771204lfg.2 for <netmod@ietf.org>; Mon, 11 Dec 2017 12:55:31 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yumaworks-com.20150623.gappssmtp.com; s=20150623; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=7fRZLSI/E1KXckeLggr3bqIGezVQEffWLuNcExJF3rM=; b=C2QIdJMbVmU+I8PbaIE/amVY5GDLQVpYtazxBNPBQZtMFAqDThiCPnboCPbfTQvo2k 0wzpWqPGZ+PWz/Q2D3rbpd/bTs9yC4coBum+HWheOw4xe0GVsXlkbDg/bQjno3fP6O4u EPrnMfdSpKySmOCRtfmxyG5qheVLk0atE+dByDa+eizFjSHwsg4CrEhJLK8scUHRTHMN MskyJXem6AyYqmZGHG50tSBBhGKxtXJ36+b19olRI6CzP2fs5UXxSD6F+Ohfiwb1huL0 /EzrXGjmymAq4kp05At3cd7qf6AJSKgVUSVMQ4d44bWyWF+eP4BBXsugEK/NUUH8GI6z Db+g==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=7fRZLSI/E1KXckeLggr3bqIGezVQEffWLuNcExJF3rM=; b=aKlHwRkEpTkZUiwG3xp/7hHYVZYtf0nFHyAr0qVEBS+ma6Qhx86W3spYt2AGVcWLH1 8twio9nkUqVwcvNOsN46KPx0Mb3luAW2G2B9RcW+9MKV+h7x4inCWdvSc6AQoTlfU7UQ CE6kFkwRc/CU0ZkpPCewM+/ZCTwm02LT6azJ9Ljm+dt0Wp6PTXMiXDHBKeBd/8brb2gP nYsQc7zSrze/2Aws+IicwIyDlZphP3EieaejqsV8U4cUyYGPl/VsmiSGXbEJkCBumFLx 6vjcNx0tGXTJNlDid8Pm+4+D7rwVvwrZV8rlb5Ho6qdtX5OXELPTsrEIx5H77fTozTVs tauA==
X-Gm-Message-State: AKGB3mJBE/FFcCgPsAn2twgc6SO7UvkwkIPWvyn+PLjGSScHn08urEwi saRGdH9XX+mKIB+Y/VwP2rRMLxLfnJxyCI30vRzWbQ==
X-Google-Smtp-Source: ACJfBouMaGVsjOFZo5wVjlDCd9Rq9xBpMNqOrj3KB6Gz8bgkl8AYs7dGNOoCSzlvTAdqQDl4TZ4xE/iB+91i2gn0pGU=
X-Received: by 10.46.70.18 with SMTP id t18mr826704lja.190.1513025730095; Mon, 11 Dec 2017 12:55:30 -0800 (PST)
MIME-Version: 1.0
Received: by 10.25.33.81 with HTTP; Mon, 11 Dec 2017 12:55:28 -0800 (PST)
In-Reply-To: <5242d50f-6f9e-b57e-ec1b-64828c456339@cisco.com>
References: <75e91419-9436-d1b7-29f6-02e3ff4ff86d@transpacket.com> <668cc9e1-c006-ce25-1473-549bc0b71a7d@cisco.com> <6cc655e0-1c28-fe75-b854-08e2d878816c@transpacket.com> <20171208.160306.109290175567894287.mbj@tail-f.com> <20171208150614.axuynu4atpg7aaj2@elstar.local> <b3159aa5-93e4-23eb-406e-083289a4767d@transpacket.com> <20171208153442.roomf7rhixtckrfk@elstar.local> <1512750289.11843.3.camel@nic.cz> <C030AD08-2E8B-4248-994B-04C802296024@juniper.net> <CABCOCHQZLirVDqGNysAkRFXruPKxyXrBQ+xyagU9y3QHRV6d0g@mail.gmail.com> <5242d50f-6f9e-b57e-ec1b-64828c456339@cisco.com>
From: Andy Bierman <andy@yumaworks.com>
Date: Mon, 11 Dec 2017 12:55:28 -0800
Message-ID: <CABCOCHSoa8b8=ieips0QguHovi=-8qATb+A3F+iKFu34ikA8Jw@mail.gmail.com>
To: Robert Wilton <rwilton@cisco.com>
Cc: Kent Watsen <kwatsen@juniper.net>, "netmod@ietf.org" <netmod@ietf.org>, "netconf@ietf.org" <netconf@ietf.org>
Content-Type: multipart/alternative; boundary="f403045f771e2dcb01056016c1e9"
Archived-At: <https://mailarchive.ietf.org/arch/msg/netmod/YSEzc-8Q8nmQfNIkwPVNi2zQLEs>
Subject: Re: [netmod] [Netconf] Alternative YANG library structure for 7895bis
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, 11 Dec 2017 20:55:41 -0000

On Mon, Dec 11, 2017 at 2:57 AM, Robert Wilton <rwilton@cisco.com> wrote:

> Hi,
>
> On 08/12/2017 18:01, Andy Bierman wrote:
>
> Hi,
>
> A library per datastore sounds too complicated.
> I prefer the proposal that was made at the IETF meeting that had
> a 'not-implemented-in' leaf-list and a single module list.
>
> The use case that this particular design doesn't work particularly well
> for is if you have a dynamic datastore that just contains a few modules
> that are not supported via the conventional datastores.
>
> I think that there are future uses cases where the set of modules used for
> a dynamic datastore could be really quite different and separate from
> conventional configuration.  E.g. if dynamic subscribers were managed
> through a dynamic configuration datastore rather than RADIUS.
>
>
> Why is it interesting to have a separate module list for regular modules
> and imported modules?
>
> Several reasons:
> 1) It means that the list of implemented modules have a single key and
> hence any references to an implemented module are cleaner/simpler.
>


IMO you are replacing universally meaningful keys  (module-name,
revision-date) with an arbitrary name,
It is not cleaner and not simpler for a client.


2) The model structure naturally more strictly enforces that only a single
> revision/version of a module is implemented.  (E.g. it prevents a server
> stating that two revisions of a module are both implemented).
>


How is that the case if the schema list includes its own module list?
You mean there is a "unique" statement in the outer list that insures that
a module/revision
shows up at most once in all instances of the inner module list?



> 3) I genuinely think that the list of implemented modules is more
> interesting to the client than the imported, but not implemented modules.
>


The conformance leaf was good enough.
Duplicating the module list and removing the conformance leaf is
aggressively non-backward compatible.



>
> For a server, I would design it to "implement" one revision of every
> module that it uses (including those that don't contain any data nodes,
> RPCs, actions, notifications, or deviations), and then the "import-only"
> list becomes the list of modules that the server implements to satisfy
> "import-by-revision" and these are stated in the implemented schema anyway.
>
>
> I prefer to keep the conformance leaf and not change the module list.
>
> NMDA needs to be possible to implement with a single schema tree such that
> a module
> is implemented in all datastores, or a subset of all datastores.
> Otherwise it probably won't
> get supported in clients.
>
> All solutions accommodate this requirement.
>


Seems to me all new solutions allow a server to violate the MUST in the
NMDA draft that
there is a superset of all modules.  A client has to look for every module
in a server-specific
set of named schema sets, and then reconcile all these sets.
I still prefer the single module list with a conformance leaf and a
leaf-list indicating
the supported (or unsupported) datastores.



> For me, some of the interesting design questions have revolved around:
> - is it better to reduce duplication in the list of modules reported at
> the cost of increased model complexity?
> - does the solution extend to schema mount?
> - how well does the solution cope with with configuration datastores that
> support very different sets of modules?
>
> To a lesser extent we have also been considering how well the solution
> extends to packaging and semantic versioning, but I think that it is quite
> tricky to know who these are going to pan out.  E.g. I think that the
> restriction that a given schema will only implement a single revision of a
> module will end up still holding, but I'm not sure that everyone has that
> same view point.
>
> Thanks,
> Rob
>
>
>

Andy


>
>
> Andy
>
>
>
> On Fri, Dec 8, 2017 at 9:21 AM, Kent Watsen <kwatsen@juniper.net> wrote:
>
>> CC-ing NETCONF, where the draft is being worked on.
>>
>> Kent
>>
>>
>> On Fri, 2017-12-08 at 16:34 +0100, Juergen Schoenwaelder wrote:
>> > On Fri, Dec 08, 2017 at 04:19:28PM +0100, Vladimir Vassilev wrote:
>> > >
>> > > Yes. The default value for yang-library-datastore leaf is
>> ds:operational
>> > > (the only possible one for the ds:operational datastore). This is
>> backward
>> > > compatible. If one needs different model for 'running', etc. then a
>> new
>> > > datastore identity has to be defined  and set in place of the default
>> value.
>> > > Then this identity can be used to read the yang-library data with
>> > > <get-data>.
>> > >
>> >
>> > Sorry, but I have to ask this: How do I obtain the schema for the
>> > datastore (lets call it <running-library>) that reports the schema for
>> > <running>? Is there another <running-library-library> datastore? Will
>> > the recursion end? Perhaps it does since <running-library-library>
>> > might have itself listed as the schema defining datastore. I guess
>> > Lada will like these kind of meta and meta-meta datastores.
>>
>> Not really. Metadata needn't be in datastores.
>>
>> Lada
>>
>> >
>> > /js
>> >
>> --
>> Ladislav Lhotka
>> Head, CZ.NIC Labs
>> PGP Key ID: 0xB8F92B08A9F76C67
>>
>> _______________________________________________
>> netmod mailing list
>> netmod@ietf.org
>> https://urldefense.proofpoint.com/v2/url?u=https-3A__www.iet
>> f.org_mailman_listinfo_netmod&d=DwICAg&c=HAkYuh63rsuhr6Scbfh
>> 0UjBXeMK-ndb3voDTXcWzoCI&r=9zkP0xnJUvZGJ9EPoOH7Yhqn2gsBYaGTv
>> jISlaJdcZo&m=5qj6BQUSwqYmkAVeKz5axFV8k3gxYEPSJ5Cp0RSnxrE&s=I
>> 7fR1GY5lN2hVMkDuvryrhDeRypike3wPeFRrvQI5l8&e=
>>
>>
>> _______________________________________________
>> netmod mailing list
>> netmod@ietf.org
>> https://www.ietf.org/mailman/listinfo/netmod
>>
>
>
>
> _______________________________________________
> Netconf mailing listNetconf@ietf.orghttps://www.ietf.org/mailman/listinfo/netconf
>
>
>