Re: [yang-doctors] Features and must-condition

Ebben Aries <exa@juniper.net> Thu, 25 January 2018 03:50 UTC

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Date: Wed, 24 Jan 2018 20:50:38 -0700
From: Ebben Aries <exa@juniper.net>
To: Benoit Claise <bclaise@cisco.com>, Andy Bierman <andy@yumaworks.com>, "Reshad Rahman (rrahman)" <rrahman@cisco.com>, "yang-doctors@ietf.org" <yang-doctors@ietf.org>
Message-ID: <20180125035038.mxf7sm4f773czuof@smtp.juniper.net>
References: <9E242E7E-E87D-41C7-BFED-EB8185195F26@cisco.com> <20180110.223316.2175524120457720164.mbj@tail-f.com> <20180110220131.xmsorl4gwixqv77s@smtp.juniper.net> <16188AE1-697A-47E4-817B-CB6D7CE6D0B9@cisco.com> <20180110222610.qgdknjrkxdw65jbk@smtp.juniper.net> <20180110223801.hx23svra4xpuww2i@elstar.local> <CABCOCHQEsHGETaKnfa7bBM955h1L28WqqcT72MSRm4xcoNW1pw@mail.gmail.com> <20180110232830.6rqbhpw5s55kx6zo@elstar.local> <29599bf2-f920-355c-8b3f-a7d696380e73@cisco.com> <20180116174323.e2b4zr5ffgrycnei@elstar.local>
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Archived-At: <https://mailarchive.ietf.org/arch/msg/yang-doctors/Y0xnSYzQebIwQdZ6AwOQIoidn0Q>
Subject: Re: [yang-doctors] Features and must-condition
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I think this change looks good

On Jan 16 18:43 PM, Juergen Schoenwaelder wrote:
> On Tue, Jan 16, 2018 at 06:03:05PM +0100, Benoit Claise wrote:
> > On 1/11/2018 12:28 AM, Juergen Schoenwaelder wrote:
> > > On Wed, Jan 10, 2018 at 02:49:48PM -0800, Andy Bierman wrote:
> > > > The feature-per-leaf approach should not be approved by YD.
> > Do we want to add a sentence in
> > https://urldefense.proofpoint.com/v2/url?u=https-3A__tools.ietf.org_html_draft-2Dietf-2Dnetmod-2Drfc6087bis-2D15-23section-2D4.17&d=DwIBAg&c=HAkYuh63rsuhr6Scbfh0UjBXeMK-ndb3voDTXcWzoCI&r=GIehbDpQlo31lSi6WbnEkA&m=coUU0hud2Ev6mARcSeDrSXnjLioAu_TOiWqw0BDn_c4&s=yaqHtXjjzMi643nHVelr4Zq0_YelOsvOMfEMImH4NHE&e=,
> > expressing that a feature-per-leaf is most likely the wrong approach?
> 
> This is difficult to describe. Perhaps something like this is a
> reasonably small change to the existing text (which only talks about
> too big features but not about too small features).
> 
> OLD
> 
>    The YANG "feature" statement is used to define a label for a set of
>    optional functionality within a module.  The "if-feature" statement
>    is used in the YANG statements associated with a feature.
> 
>    The set of YANG features available in a module should be considered
>    carefully.  The description-stmt within a feature-stmt MUST specify
>    any interactions with other features.
> 
>    If there is a large set of objects...
> 
> NEW
> 
>    The YANG "feature" statement is used to define a label for a set of
>    optional functionality within a module.  The "if-feature" statement
>    is used in the YANG statements associated with a feature.  The
>    description-stmt within a feature-stmt MUST specify any
>    interactions with other features.
> 
>    The set of YANG features defined in a module should be considered
>    carefully. Very fine granular features increase interoperability
>    complexity and should be avoided. A likely misuse of the feature
>    mechanism is the tagging of individual leafs (e.g., counters) with
>    separate features.
> 
>    If there is a large set of objects...
> 
> /js
> 
> -- 
> Juergen Schoenwaelder           Jacobs University Bremen gGmbH
> Phone: +49 421 200 3587         Campus Ring 1 | 28759 Bremen | Germany
> Fax:   +49 421 200 3103         <https://urldefense.proofpoint.com/v2/url?u=https-3A__www.jacobs-2Duniversity.de_&d=DwIBAg&c=HAkYuh63rsuhr6Scbfh0UjBXeMK-ndb3voDTXcWzoCI&r=GIehbDpQlo31lSi6WbnEkA&m=coUU0hud2Ev6mARcSeDrSXnjLioAu_TOiWqw0BDn_c4&s=TlDlQ41jN97aNeLJGGDlYf6DPYwdLss2UmogmWbTPTU&e=>