Re: [netmod] YANG next

Juergen Schoenwaelder <j.schoenwaelder@jacobs-university.de> Tue, 23 July 2019 18:23 UTC

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Date: Tue, 23 Jul 2019 20:23:04 +0200
From: Juergen Schoenwaelder <j.schoenwaelder@jacobs-university.de>
To: Ladislav Lhotka <lhotka@nic.cz>
CC: Andy Bierman <andy@yumaworks.com>, NETMOD WG <netmod@ietf.org>
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Subject: Re: [netmod] YANG next
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On Tue, Jul 23, 2019 at 02:00:29PM -0400, Ladislav Lhotka wrote:
> 
> This problem is actually not limited to YANG itself - people are reporting
> problems with the transition to NMDA. 
>

The YANG update from 1 to 1.1 mostly affected compiler writers - and
to a much lesser extend module authors and module implementors. NMDA,
affects client and server implementors much more directly, additional
instrumentation on the server side needs to be written, application
logic on the client side needs to be adjusted. NMDA is an evolution of
architectural principles and this already indicates that there is a
certain investment to make.

If we discuss YANG next, we should compare it to the YANG 1 to 1.1
transition and not to the NMDA transition. When we started YANG 1.1
work, there were people who said that nobody would implement it. But
then implementations were adopted relatively fast when we finalized
YANG 1.1.

While a collection of patches (updates) of YANG 1.1 may sound simpler,
I am not sure this is really true. We will loose a common baseline and
instead get complexity since we will get systems that all support
different sets of patches (updates) of YANG 1.1. I believe we are all
much better off if we have a common baseline language and tools that
support the common baseline language. Again, if done right, YANG next
will mostly affect compiler writers and tool makers and not so much
module authors and implementors.

/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/>