Re: [Netconf] {+restconf}/data vs <running>

[Juergen Schoenwaelder <[e-mail]>]

On Wed, Sep 26, 2018 at 01:10:53PM +0200, Ladislav Lhotka wrote:
> On Wed, 2018-09-26 at 12:58 +0200, Juergen Schoenwaelder wrote:
> > On Wed, Sep 26, 2018 at 12:45:26PM +0200, Ladislav Lhotka wrote:
> > > Hi,
> > > 
> > > draft-ietf-netconf-nmda-restconf is silent about the relationship
> > > between the {+restconf}/data and the <running> datastore, and it cannot
> > > be deduced from RFC 8040 either, because it only says in sec. 3.3.1:
> > > 
> > >    This mandatory resource [{+restconf}/data] represents the combined
> > >    configuration and state data resources that can be accessed by a
> > >    client.
> > > 
> > > I think this is a serious omission.
> > 
> > We are not changing {+restconf}/data.
> 
> My point is that it is unclear what {+restconf}/data really is: "the combined
> configuration and state data resources" is too vague given that several
> configuration datastores may be present.
>

Well, {+restconf}/data is whatever RFC 8040 says it is. We are not
changing it. If you want to interact with an NMDA datastore, then
there is a defined way to do so.

> > > Regarding draft-lhotka-netconf-restconf-transactions-00, I received a
> > > lot of criticism for changing the semantics of
> > > {+restconf}/data. However, I don't think it was the case: according to
> > > the above definition, it seems perfectly OK if {+restconf}/data
> > > represents combined configuration **from <staging>** and state data.
> > 
> > Perhaps people had the impression that your proposal changes
> > {+restconf}/data or that it should work with the NMDA solution.
> 
> I am arguing that I did NOT change {+restconf}/data, I just made its
> definition more precise.

Making something more precise may be seen by others as changes. Within
the NMDA work, we quickly discovered that the only backwards
compatible way to introduce NMDA to RESTCONF is to expose NMDA
datastores as new resources instead of trying to give an existing
resource a different meaning.
 
> If configuration resources under {+restconf}/data are expected to be
> identical to those under {+restconf}/ds/ietf-datastores:running,
> then draft-ietf-netconf- nmda-restconf should say so.

NMDA does not say what {+restconf}/data is because RFC 8040 defines
what {+restconf}/data is. Among other things, RFC 8040 says this:

      By default, RESTCONF
      methods access a unified view of the underlying datastore
      implementation on the server.

So {+restconf}/data is most likely not the same as
{+restconf}/ds/ietf-datastores:running.

/js

-- 
Juergen Schoenwaelder           Jacobs University Bremen gGmbH
Phone: [phone]         Campus Ring 1 | 28759 Bremen | Germany
Fax:   [phone]         <https://www.jacobs-university.de/>