Re: [netmod] WG Last Call: draft-ietf-netmod-revised-datastores-04 guessing

[Robert Wilton <[e-mail]>]

The authors have discussed this issue 
(https://github.com/netmod-wg/datastore-dt/issues/15), and their 
proposal is to close this with no change to the NMDA draft with the 
following justifications:

1) This assumption is that longer term all models would become NMDA 
compliant and over time it would likely require that all modules would 
need to have this extension added, creating a CLR.

2) Defining the extension would take time, and further delay the IETF 
standardization of YANG models, but it is important that IETF actually 
gets standard YANG models published as quickly as possible so that they 
can be implemented by the industry.

3) NMDA devices can implement "non NMDA style" modules (but with 
duplication of state), and non NMDA devices can implement "NMDA style" 
modules (but with reduced functionality).

4) YANG Catalog can identify what type of style a particular module is, 
by using some heuristically analysis of the structure of the model.

Thanks,
Rob


On 15/09/2017 13:21, Martin Bjorklund wrote:
> Ladislav Lhotka <[e-mail]> wrote:
>> t.petch píše v Pá 15. 09. 2017 v 12:29 +0100:
>>> Looking at a YANG module in future, how can I tell whether or not it is
>>> written to work with revised datastores?
>> Ideally, this ought to be a wrong question. A YANG module (or rather a YANG data
>> model) should specify constraints for a data tree, no matter where the tree
>> happens to reside.
> I agree, and an old module can be implemented in an NMDA-compatible
> server (with some redundant info), and a new modules can be implemented in a
> non-NMDA-compatible server (with limited functionality).
>
> But the truth is that modules are and will be designed to fit into
> some environment (or "meta model").  For example, with NMDA, there
> will be a single tree.  If we had an annotation for "comments" on
> nodes, you wouldn't see any leafs called "description".  If we didn't
> have the ability to create things in the protocol, our models would
> have objects of type "RowStatus".  Etc.
>
>
> /martin
>
>
>> Coupling a data modelling language with rather specific aspects of an NM
>> application is a bad design.
>>
>> Lada
>>
>>> If the module is written assuming revised datastores and the environment
>>> does not support this in some regard, then we have a management
>>> malfunction, which could be disastrous.
>>>
>>> I think that there should be some mechanistic way, something that can be
>>> automated, for a system to check whether or not a module is assuming
>>> revised datastores or not.  This is a bit like the change from YANG 1.0
>>> to YANG 1.1; there needs to be a way of telling what environment the
>>> module is written for, and so we have the
>>>
>>> yang-version 1.1;
>>>
>>> statement.
>>>
>>> Revised datastores needs something similar in the module.
>>>
>>> Tom Petch
>>>
>>>
>>> ----- Original Message -----
>>> From: "Lou Berger" <[e-mail]>
>>> 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
>>>>
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>> -- 
>> Ladislav Lhotka
>> Head, CZ.NIC Labs
>> PGP Key ID: 0xB8F92B08A9F76C67
>>
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