I think that in one respect, perhaps the key respect, this I-D fails to
state the obvious (or at least what is likely obvious to those who have
been at this for a while:-).

The problem that is hinted at but never explicitly stated is that data
objects can appear both as configuration and as state, e.g. when learned
by other means or at other times.  The original model of datastores
required these data objects to be modelled twice, as configuration false
and as configuration true, and since there could be many of them, and
the rules of YANG require them to be in separate trees, this led to a
twin-trees approach such as can be seen in RFC7277 or RFC7223.

Amongst other problems, this separation of operational state from
configuration in a
   separate branch in the data model has been found to be operationally
   complicated and impacts the readability of module
   definitions.  The relationship between
   the branches is not machine readable and filter expressions operating
   on configuration and on related operational state are different.

With revised datastores, there is a single data object to model both
values  but this now appears in two datastores, one for the
configuration value, one for the operational state value.

Instead of two YANG data nodes there is one data node in two datastores,
a more elegant and simpler solution to the problem.


I believe that text such as this would make the I-D much easier to
follow.  As it stands, you have to read between the lines and speculate.

Tom Petch


----- Original Message -----
From: "Lou Berger" <[email protected]>
To: "netmod WG" <[email protected]>
Cc: <[email protected]>;
<[email protected]>
Sent: Friday, September 01, 2017 10:02 PM

> All,
>
> This starts a two week working group last call on
> draft-ietf-netmod-revised-datastores-04.
>
> The working group last call ends on September 17.
> Please send your comments to the netmod mailing list.
>
> Positive comments, e.g., "I've reviewed this document and
> believe it is ready for publication", are welcome!
> This is useful and important, even from authors.
>
> Thank you,
> Netmod Chairs
>
> _______________________________________________
> netmod mailing list
> [email protected]
> https://www.ietf.org/mailman/listinfo/netmod

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