Re: [core] Questions/Review on draft-ietf-core-resource-directory-12

[peter van der Stok <[e-mail]>]

Hi Jim and Christian,

The discussion on a set of RDs is rather worrying to me.
I do understand the remark by Jim that the end-points composing a group 
could be stored on different RDs than the RD handling the group 
registration.
The RD is not aware of the remoteness of the eps and the client has to 
handle the distribution.
It is not different from registering anchors to different hosts.

However, envisaging a set of RDs implies many protocols to keep entries 
synchronized and handle communication errors.
I hope I misunderstood the intention of Christian.

Greetings,

Peter

>> On Tue, Oct 31, 2017 at 05:25:50PM -0700, Jim Schaad wrote:
>> > 1.  When creating a group registration, can the link to an endpoint be
>> > on a different resource directory?  This second RD could be either on
>> > a different machine or on the same machine (i.e. coap vs coaps).  If
>> > the answer is no, then do we need to think about some type of relation
>> > attribute in the case that multiple are listed somewhere?
>> 
>> I like to think so (having a more distributed model in mind), but we
> haven't
>> discussed it yet.
>> 
>> As for the specification, I think we should say that the CTs operating 
>> on
> the tool
>> working on the group "SHOULD refer to the endpoint registrations 
>> either as
> a
>> path-absolute relative reference (if it obtained the reference from 
>> the
> Location
>> option when it conducted the registration itself), or use the 
>> reference as
>> serialized when it obtained the location from an endpoint lookup from 
>> the
>> same RD origin".
>> 
>> This leaves the door open for federating RDs (where some endpoint
>> registrations are located at another RD host, but still available for
> lookup at the
>> closest host), but discourages blind mixing of registration entities 
>> from
>> unrelated RDs.
>> 
>> (Discussion about this can go continue on-list, but for tracking 
>> purposes
> it's
>> tracked at [85] too).
> 
> I really like the idea of being able to have entries in a group be on a
> different server, right up to the point where I start trying to 
> implement
> the search algorithm that you have specified.  At that point my code is
> suddenly making lots of potential queries to the other RD in order to 
> find
> out if some parent/child is going to have the attribute that I am 
> looking
> for.
>