Ladislav Lhotka <[email protected]> wrote: > > > On 11 Jan 2017, at 10:36, Martin Bjorklund <[email protected]> wrote: > > > > Ladislav Lhotka <[email protected]> wrote: > >> > >>> On 10 Jan 2017, at 09:39, Juergen Schoenwaelder > >>> <[email protected]> wrote: > >>> > >>> On Tue, Jan 10, 2017 at 09:20:36AM +0100, Ladislav Lhotka wrote: > >>>> > >>>> I think we need protocol and YANG specs that are not tied to any > >>>> particular model and that are thus capable of matching unforeseen > >>>> real-world implementations. This is no sci-fi, HTTP and XML schema > >>>> languages work this way. > >>>> > >>> > >>> I disagree that HTTP and XML schema languages do the same thing. Our > >>> goal is interoperable configuration of network devices; the notion of > >> > >> Even now, a client that's programmed to write straight to running > >> isn't interoperable with a server that has candidate and read-only > >> running. A RESTCONF server that supports only JSON isn't interoperable > >> with a client that supports only XML. > >> > >> We are not in a situation that every pair of a randomly chosen server > >> and client need to be interoperable. It's IMO perfectly fine if IoT > >> and ISP networks use different clients. Yet, both can still use the > >> same RESTCONF, same YANG, and even same YANG modules. > > > > The fact is that that data models are written with a certain set of > > protocol features and datastores in mind (the "meta-model"). Some > > examples: > > > > If we had an "operational-state" datastore like the one proposed, we > > would not see the /foo vs /foo-state split. > > Yes, but I assume this will go away anyway. However, we can still have > YANG modules (and complete schemas) designed for the operational > datastore. The important property of the "meta-model" so far has been > that config and state data are separate, and this is not going to > change. > > > > > If SNMP would have had a CREATE operation, MIBs would not have used > > RowStatus. If NETCONF didn't have a way to create instances, we would > > have seen something similar in YANG models. > > > > If NETCONF had a way to add comments to any node in a datastore, we > > wouldn't have "leaf description" sprinkled throughout the models. > > > > If NETCONF didn't have a generic way to filter retreived data, we'd > > see lots of specific get-* rpcs in YANG models. > > Maybe, but are the last three points relevant to this discussion?
The point is that data models are designed with some meta-model in mind. The meta-model includes (some) datastores. You wrote: I believe both the protocols and YANG can work with any set of datastores [...] And I don't think that this is true (practically). For example, a YANG module that is designed with the new operational state datastore in mind will be of limited use in a legacy NETCONF server. /martin _______________________________________________ netmod mailing list [email protected] https://www.ietf.org/mailman/listinfo/netmod
