Re: [dnssd] [core] CoAP resource discovery and DNS-SD

[Toerless Eckert <[e-mail]>]

On Sat, May 14, 2022 at 01:44:06AM +0200, Carsten Bormann wrote:
> On 2022-05-14, at 01:35, Toerless Eckert <[e-mail]> wrote:
> > 
> > It does not describe how to describe the parameters i was looking for:
> > priority, weight, key=value
> 
> CoRE resource discovery was designed to discover resources, not to emulate specific features of other service discover protocols.
> 
> Can you explain what you are trying to do without phrasing this in DNS-SD terms?

I send a coap resource discovery to ff05::fd and there are three different
nodes replying because they all have this resource. But lets say one of
them is meant to be an emergency backup not to be used when any other is
present (prio=0), the other two are meant to be used primarily (prio=1),
but one of them has a lot more performance to serve the resource, so
the client should stochastically select it with a 9 times higher probability
than the other (w=9) vs. w=1). Aka All three instances are announcing
a weight and priority value in their reply and the client picks the
appropriate one.

Likewise, for other parameters, the client gets replies from multiple
instances, but they resource differs in some details and those are expressed
in those additional parameters.

Cheers
    toerless