Re: [netmod] Issues with draft-ietf-netmod-nmda-diff-00

Juergen Schoenwaelder <j.schoenwaelder@jacobs-university.de> Tue, 06 November 2018 17:41 UTC

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Date: Tue, 6 Nov 2018 18:41:42 +0100
From: Juergen Schoenwaelder <j.schoenwaelder@jacobs-university.de>
To: Andy Bierman <andy@yumaworks.com>
CC: NetMod WG <netmod@ietf.org>
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Subject: Re: [netmod] Issues with draft-ietf-netmod-nmda-diff-00
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On Tue, Nov 06, 2018 at 09:31:19AM -0800, Andy Bierman wrote:
> 
> The next problem is that some data types have no canonical representation.
> 

YANG requires a canonical format, xpath expressions for example are
evaluated against the canonical representation. Data types that have
no canonical representation need to be fixed if we want interoperable
behaviour (independent of any diff solutions).

That said, I tend to agree with your other points that diff should be
calculated on the data tree and not its serialization and that a diff
and patch algorithm has to be smart to take different orders, that are
entirely possible, into account (unless we want to go down the path of
defining a canonical order for the tree itself, which I expect to hit
quite some resistance).

/js

-- 
Juergen Schoenwaelder           Jacobs University Bremen gGmbH
Phone: +49 421 200 3587         Campus Ring 1 | 28759 Bremen | Germany
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