Re: [netmod] Comment on draft-clacla-netmod-yang-model-update-02

[Ladislav Lhotka <[e-mail]>]

On Wed, 2017-11-15 at 18:12 +0800, Balazs Lengyel wrote:
> The server MAY implement obsoleted nodes or MAY NOT. This may or may 
> not  is not good enough as a contract for the management client.  My 
> problem is that the current solution is just not good enough. IMHO we 
> need to change it.

I agree. My observation has been that the YANG contract is often interpreted in
a very server-centric way: clients just have to be prepared to any surprises.
(This reminds me of the contracts I have with insurance companies.)

Yet I think it is quite important to also support dumb clients that are written
to do some job, and may easily break if a node suddenly disappears.

Lada

> 
> Even after semver you can still obsolete the old stuff and provide the 
> new stuff with a new name, although that might not be the common 
> practice.  Which is a good thing, as I believe it is sometimes better to 
> correct existing definitions then to replace them.
> 
> regards Balazs
> 
> 
> On 2017-11-15 16:53, Martin Bjorklund wrote:
> > Exactly.  With the current solution, the sever can still implement the
> > deprecated or obsolete nodes in order to support old clients.
> > 
> > With a MAJOR update in a semver world, it means that the old nodes are
> > removed (or rather, possibly, that the old nodes have new syntax
> > and/or semantics).
> > 
> > 
> > 
> 
> 
-- 
Ladislav Lhotka
Head, CZ.NIC Labs
PGP Key ID: 0xB8F92B08A9F76C67