Re: [netmod] upcoming adoptions

[Andy Bierman <[e-mail]>]

Hi,

I suggested the naming guideline because the NMDA design team decided to
add semantics to certain naming patterns, so authors have to be warned.

But this is a really bad idea (and slippery slope).
First we tell everybody "these are just identifiers, pick any string you
want",
then we want to change it 8 years later to "except these strings which mean
special things".

The proper deterministic way to identify that the module or subtree is
special
is to tag it with a YANG extension. Adding semantics to the user-selected
identifier space
8 years after dozens of exceptions already exist is not a great plan.

If anybody ever actually implements this NMDA stuff, I think they will find
it useful to identify modules written for specific datastore usage, or
if the module is an NMDA transition module, an I2RS-specific module, etc.
The extension you suggested in another email would work.


Andy


On Thu, Sep 7, 2017 at 4:10 AM, Martin Bjorklund <[e-mail]> wrote:

> Robert Wilton <[e-mail]> wrote:
> >
> >
> > On 07/09/2017 11:15, Martin Bjorklund wrote:
> > > Robert Wilton <[e-mail]> wrote:
> > >>
> > >> On 07/09/2017 11:05, Martin Bjorklund wrote:
> > >>> Robert Wilton <[e-mail]> wrote:
> > >>>> On 07/09/2017 03:36, Andy Bierman wrote:
> > >>>>> On Wed, Sep 6, 2017 at 10:57 AM, Kent Watsen <[e-mail]
> > >>>>> <mailto:[e-mail]>> wrote:
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>>       >> /netconf-state and /restconf-state don't seem to follow
> the
> > >>>>>       >> general
> > >>>>>       >> pattern we're correcting with the various NMDA updates.
> > >>>>>       Particularly,
> > >>>>>       >> these -state trees are NOT for the purpose to providing
> the
> > >>>>>       >> opstate
> > >>>>>       >> value for configured nodes.  These modules have the
> misfortune
> > >>>>>       >> of
> > >>>>>       >> having "-state" in their name, but they're otherwise fine.
> > >>>>>       >
> > >>>>>       >
> > >>>>>       > This contradicts some details we have been told about NMDA
> > >>>>>       >
> > >>>>>       > 1) the transition guidelines say otherwise
> > >>>>>       >
> > >>>>>       > New modules and modules that are not concerned with the
> > >>>>>       > operational state of configuration information SHOULD
> > >>>>>       > immediately be structured to be NMDA-compatible
> > >>>>>
> > >>>>>       Yes, I'm suggesting we give ourselves some leeway, by taking
> > >>>>>       advantage of the SHOULD keyword above and defer updating
> these
> > >>>>>       two modules to when it makes more sense to do so.
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>>> OK -- good.
> > >>>>> I think another sentence needs to be added.
> > >>>>>
> > >>>>>
> > >>>>> NMDA compatibility conversion MAY be deferred if the module
> > >>>>> does not contain any configuration datastore objects.
> > >>>> I agree.
> > >>> +1
> > >>>
> > >>>
> > >>>>>       > 2) RD defines operational state to include config=false
> nodes
> > >>>>>       > such as counters, so these modules are properly named.
> > >>>>>
> > >>>>>       module-name == top-level node name.  Either way, my point is
> that
> > >>>>>       the -state tree in these modules is not trying to provide the
> > >>>>>       opstate value for configured nodes (i.e. applied
> configuration).
> > >>>>>
> > >>>>>
> > >>>>> So a data node naming convention is needed?
> > >>>>> And a module naming convention?
> > >>>>>
> > >>>>> We need a rule that says the suffix "-state" is reserved for NMDA
> > >>>>> compatibility
> > >>>>> so module names and data nodes SHOULD NOT be named with an
> identifier
> > >>>>> that
> > >>>>> ends in this suffix.
> > >>>> Also agree.
> > >>> -1
> > >>>
> > >>> There are cases where a -state suffix is natural, e.g. in
> > >>> ietf-hardware we have admin-state, oper-state, usage-state etc.
> > >>>
> > >>> I prefer to have a recommendation that generated modules and
> top-level
> > >>> nodes are called ...-state, but that should not be a reason for
> making
> > >>> -state illegal in general.
> > >> Sorry, it was specifically modules and top level data nodes that I
> > >> think this restriction should apply to.
> > > Even in this case I'd prefer to make a one-way recommendation.  Is
> > > there a technical reason for not allowing a normal module or top-level
> > > node be called ...-state?  IMO, *if* it is important to mark these
> > > modules as being generated, we should use a formal way to convey this
> > > information, not rely on a naming convention.  (i.e., use a YANG
> > > extension in the module).
> > My logic is slightly different:
> >
> > I think that new top level containers shouldn't be called ...-state
> > because either
> > (i) they already contain config nodes, in which case they are
> > misnamed, or
> > (ii) they might be revised to contain config nodes in the future, in
> > which case they would end up being misnamed.
> >
> > I basically, think that the suffix "-state" doesn't generally provide
> > any useful extra information.
>
> Sure.  But there are many suffixes that don't generally provide useful
> extra information.  I just think we should be careful with these kinds
> of rules.  Bad names are hopefully catched during the review process.
>
> > Lower down the tree, I guess that using "state" or  "*-state" is OK if
> > it can be known that the leaf/container will *always* only be state
> > and never potentially be configurable in future.  But I still think
> > that it is necessary to be very careful here.
> >
> > For example, If I designed a new routing protocol, then in v1 there
> > might be no explicit neighbor configuration, and hence I put all of
> > the neighbor information into a container call
> > neighbor-state. However, if a v2 version of that protocol (or vendor
> > extensions) wants to add some per neighbor configuration then it would
> > hit the problem that the original container is poorly named to be
> > updated to now also hold configuration.  So, generally avoiding
> > "-state" in the name of containers seems to be good common sense to
> > me.
>
> I agree.  And avoid "*-config".
>
>
>
> /martin
>
>
> >   I would suggest adding something to 6087bis, but my previous
> > suggested additions to 6087bis didn't appear to be well received ;-)
>
>