Subject: [netmod] Feedback on NMDA and origin

From: "Joe Clarke" <[email-masked]>
Date: Mon, 17 Jul 2017 12:06:57 -0400

In Rob’s presentation, he mentioned it would be optional to implement 
“origin” metadata.  This is done for performance reasons.  However, 
in subsequent questions, it was clear how important this MD is in 
determining why an <operational> DS looks the way it does.  Speaking as 
someone from a services organization, I would definitely want to make 
sure one could unambiguously determine (as best as possible) where a 
value came from.

So, am I misunderstanding the guidance around origin?  Could vendors 
just choose not to implement it at all?  Kent replied in Jabber that if 
this was requested by the client, the server SHOULD reply, but why not 
MUST reply if explicitly asked.  My goal is not to be stuck 
troubleshooting a server without origin and trying to track down where 
operational state came from.

Thanks.

Joe

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From: Juergen Schoenwaelder <[email-masked]>
Date: Mon, 17 Jul 2017 18:16:20 +0200

Hi,

I think the issue is not performance but implementation costs. Some
systems today do not track the origin and hence implementing the
origin metadata carries a certain cost. (Of course, one could always
return origin='unknown' but then this is not practically useful.)

Performance is a protocol interaction issue. If there is a need to
disable retrieval of metadata or a need to filter based on metadata,
then the protocol documents should take this requirement up, not the
NMDA document.

/js

On Mon, Jul 17, 2017 at 12:06:57PM -0400, Joe Clarke wrote:
> “origin” metadata.  This is done for performance reasons.  However, in
> subsequent questions, it was clear how important this MD is in determining
> why an <operational> DS looks the way it does.  Speaking as someone from a
> services organization, I would definitely want to make sure one could
> unambiguously determine (as best as possible) where a value came from.
> 
> So, am I misunderstanding the guidance around origin?  Could vendors just
> choose not to implement it at all?  Kent replied in Jabber that if this was
> requested by the client, the server SHOULD reply, but why not MUST reply if
> explicitly asked.  My goal is not to be stuck troubleshooting a server
> without origin and trying to track down where operational state came from.
> 
> Thanks.
> 
> Joe
> 
> _______________________________________________
> netmod mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/netmod

-- 
Juergen Schoenwaelder           Jacobs University Bremen gGmbH
Phone: +49 421 200 3587         Campus Ring 1 | 28759 Bremen | Germany
Fax:   +49 421 200 3103         <http://www.jacobs-university.de/>

---

From: "Joe Clarke" <[email-masked]>
Date: Mon, 17 Jul 2017 12:34:23 -0400

> return origin='unknown' but then this is not practically useful.)

Sorry, implementation cost.  Thanks.  I could not find in the -03 draft 
the text that said origin was optional.  I would hope there are strong 
guidelines are implementing this, describing some of the scenarios 
mentioned in the meeting as well as being more robust when it comes to 
troubleshooting.

Joe

>> just