Re: [netmod] [Netconf] Alternative YANG library structure for 7895bis

[Vladimir Vassilev <[e-mail]>]

On 12/12/2017 08:20 PM, Martin Bjorklund wrote:

> Hi,
>
> Vladimir Vassilev <[e-mail]> wrote:
>>
>> On 12/08/2017 04:06 PM, Juergen Schoenwaelder wrote:
>>> On Fri, Dec 08, 2017 at 04:03:06PM +0100, Martin Bjorklund wrote:
>>>> Vladimir Vassilev <[e-mail]> wrote:
>>>>> On 11/15/2017 06:29 PM, Robert Wilton wrote:
>>>>>
>>>>>> I don't think that this is really a good idea.  You would end up
>>>>>> returning server metadata in addition to the configuration.
>>>>> Obviously RFC 7895 defines only config false; data and I was not
>>>>> proposing a change to that. But I agree something has to be added to
>>>>> complete the solution. Special purpose datastore identities can be
>>>>> defined that return instance of yang-library data when read with
>>>>> <get-data>. (Datastores with yang-library config false; only data not
>>>>> represented in 'operational')
>>>>>
>>>>> Adding this special yang-library-datastore to the proposed
>>>>> ietf-datastores container e.g.
>>>>>
>>>>> module: ietf-datastores
>>>>> +--ro datastores
>>>>> |  +--ro datastore* [name]
>>>>> |     +--ro name          identityref
>>>>> |     +--ro yang-library-datastore          identityref
>>>>>
>>>> I don't understand this proposal.  How would a client learn the
>>>> library for <running>?  For <operational>?
>>> My interpretation is that the client reads the datastores list from
>>> <operational> and the list entries give you the identity of a separate
>>> datastore that gives you the content of the yang library for that
>>> datastore. (For each datastore, you have a separate datastore to
>>> report its yang library.)
>> Yes. The default value for yang-library-datastore leaf is
>> ds:operational (the only possible one for the ds:operational
>> datastore). This is backward compatible. If one needs different model
>> for 'running', etc. then a new datastore identity has to be defined
>> and set in place of the default value. Then this identity can be used
>> to read the yang-library data with <get-data>.
> Ah, ok.  This is a clever solution, but quite complicated.  It
> requires several round trips for a client to learn all library
> instances.  Also, w/o any changes, it is not clear which module-set-id
> is sent in the capability, and a client must query all module-set-ids
> in all (meta)datastores in order to just check if it has the latest
> version or not.  It is also not clear how the existing notification
> "yang-library-change" would work when there are multiple instances
> involved.
How about this?
module: ietf-datastores
...
   augment /yanglib:yang-library-change:
     +---- datastore?   identityref

Vladimir
>    So I don't think that this solution will actually work w/o
> an update to 7895 - but not updating 7895 was the whole reason for
> doing this.
>
>
> /martin
>