Re: [netmod] WG Last Call: draft-ietf-netmod-yang-instance-file-format-06

[Benoit Claise <[e-mail]>]

Juergen,

On on side, Balazs mentions:

4+ people asked me explicitly to state this similarity during the
development of the draft.

The current text is:

        P2  Instance data shall reuse existing encoding rules for YANG
            defined data.  Its format will be similar to the response of a
            NETCONF <get> operation or the RESTCONF response to a GET method
            invocation on the (unified) datastore resource.

This modification is based on your feedback:

Well, then the correct wording would be "similar to the response of a
NETCONF <get> operation or the RESTCONF response to a GET method
invocation on the (unified) datastore resource". Sounds complex and I
still prefer the text to be agnostic to specific operations

On the other side, you insist now on removing the latter sentence.
Could you propose a similar sentence that would satisfy your concern?

Regards, Benoit
> On Mon, Mar 09, 2020 at 04:17:40PM +0000, Balázs Lengyel wrote:
>> See BALAZS4 below
>>
>> -----Original Message-----
>> From: Juergen Schoenwaelder <[e-mail]>
>> Sent: 2020. március 9., hétfő 10:44
>> To: Balázs Lengyel <[e-mail]>
>> Subject: Re: [netmod] WG Last Call:
>> draft-ietf-netmod-yang-instance-file-format-06
>>
>>>> -----Original Message-----
>>>> From: Schönwälder, Jürgen <[e-mail]>
>>>> Sent: 2020. február 12., szerda 10:07
>>>> Subject: [Not Scanned] - Re: [netmod] WG Last Call:
>>>> draft-ietf-netmod-yang-instance-file-format-06
>>>>
>>>>>    - Is it necessary to describe P2 in terms of (presumably) NETCONF
>>>>>      operations? I would prefer to have the document written in a
>>>>>      protocol agnostic style. Perhaps simply drop "similar to the
>>>>>      response of a <get> operation/request".
>>>>> BALAZS: This is a reference both to NETCONF and RESTCONF. It was
>>>>> explicitly asked for by other reviewers.
>>>> Well, then the correct wording would be "similar to the response of
>>>> a NETCONF <get> operation or the RESTCONF response to a GET method
>>>> invocation on the (unified) datastore resource". Sounds complex and
>>>> I still prefer the text to be agnostic to specific operations - in
>>>> particular since <get> and the unified datastore have their
>>>> limitations. The format is simply reusing the already defined data
>>>> model encoding formats, i.e., the format has nothing to do with the
>>> operations used to retrieve the data. So I suggest:
>>>>     P2  Instance data shall reuse existing encoding rules for
>>>>         YANG defined data.
>>>>
>>>> There is no need to refer to specific protocol operations.
>>>> BALAZS: I will use both of your texts. That is the most common
>>>> question I
>>>> get: Will this use the same format as a get-reply? People like to
>>>> think in terms of a specific easy-to-grasp function instead of a
>>>> non-descript set of "existing" rules. Existing means you need to
>>>> understand X number of RFCs, while just looking up a get-reply is
>>>> easy. It is not precise, but IMHO that's how people think.
>>> If you write "reuse existing encoding rules", then actually fewer
>>> documents need to be understood. And operations have additional issues
>>> in how they interact with 'datastores', so they may even be misleading
>>> and I rather have the standards precise (and minimal normative
>> dependencies).
>>> BALAZS3: Sorry, I don't fully understand your point. What would you
>>> like in P2?
>>> The text now is:
>>> P2  Instance data shall reuse existing encoding rules for YANG
>>>         defined data.  Its format will be similar to the response of a
>>>         NETCONF <get> operation or the RESTCONF response to a GET method
>>>         invocation on the (unified) datastore resource.
>>> It refers to existing rules as you asked for and also  says" similar"
>>> to a get response, using phrasing from your email on 2020-02-12.
>>> Are you OK with this? Or how would you like to change it?
>> What I proposed above:
>>
>>     P2  Instance data shall reuse existing encoding rules for
>>         YANG defined data.
>>
>> Your additional sentence is simply wrong. Instance data from lets say
>> <operational> with _not_ be 'similar' to the response of a NETCONF <get>
>> operation or the RESTCONF response to a GET method invocation on the
>> (unified) datastore resource. The same holds true for instance data from
>> <running>.
>> BALAZS4:  I would like to keep the second part of the sentence.
>> 4+ people asked me explicitly to state this similarity during the
>> development of the draft. While your methodical and somewhat abstract way of
>> thinking has greatly helped me/us in many cases, IMHO other people often
>> think in the terms of examples and  in recognizing known similar
>> methodology. As the we use the same encoding rules for get replies and for
>> instance data, IMHO they are similar even if instance data allows some
>> additions/omissions. (People liked/requested this statement, even though
>> "similar" is a rather subjective term.)
>> Anyway it is only included in the introduction part, so while it helps some
>> people, it should not cause problems with the precise definition of the
>> format. On your request I already removed a similar statement from the
>> normative parts.
> What the sentence says is unclear or plain wrong in a number of valid
> use cases (depends on how one understands the word "similar") and thus
> this sentence is misleading and asking for trouble down the road. I
> fully understand the value of examples but here we define what is
> called a 'basic principle' - and a basic principle that is not quite
> correct for all use cases sounds like a bad idea to me.
>
> If you want to write an example after the principles that is
> identifiable as an example, I am fine with that. As the sentence is
> worded right now as part of a 'basic principle', I am having an issue
> with the it.
>
> /js
>