Identifiers 2.0 Public RFC results

[Accomazzi, Alberto]

Hi Markus,

Sorry for coming late to the discussion, but I have some concerns about
section 4.1 of the specification (Dataset Identifiers).  What troubles me
is the resolution of these identifiers, and the fact that the spec itself
states that "This specification does not exhaustively define the resolution
of publisher DIDs. Instead, we recommend the following procedure..." .
Here is why I think this is a problem:

- the spec seems to suggests that resolving these is more a matter of
heuristics than anything else, so different implementors may chose to tweak
the logic in ways that are not totally consistent
- even if the recipe were prescriptive, an addition of a new capability
(e.g. Datalink in addition to SSA) could potentially change the way a
particular DID is resolved, thus yielding a different result at a later time
- there is no hint of what would be returned when a client tries to resolve
one of these DIDs, which I think is a problem for any application which
wants to do something with them

Ultimately I am still confused as to the role and usefulness of these DIDs:
they are not persistent, are difficult to resolve (it seems), and there is
no infrastructure for returning standard metadata about the resource that
they point to (is this correct?).  Which makes me wonder why one would not
want to use DIDs rather than plain http URIs for retrieval or more durable
identifiers if persistence and metadata registration is required.

It's possible that my confusion comes from a lack of understanding of
Datalink and the other referenced protocols, so if I am misinterpreting
things please bear with me.

Thank you as usual for your effort on an otherwise well-written spec.

-- Alberto




On Thu, Oct 1, 2015 at 9:32 AM, Markus Demleitner <
msdemlei at ari.uni-heidelberg.de> wrote:

> Dear Registry,
>
> Again on Identifiers 2.0 -- this one:
>
> On Thu, Sep 24, 2015 at 03:37:31PM +0200, Markus Demleitner wrote:
> > or just download the whole built document from
> > http://docs.g-vo.org/Identifiers.pdf (for a while).
> >
> [...]
> > Given this is a fairly serious change, I'd like to give everyone
> > interested another opportunity to re-read things.  I would, however,
> > like to go to TCG review some time between now and Oct 10th or so.
> > If you forsee you can't make it till then please let me know.
>
> I've not also implemented a PubDID resolver working as outlined in
> the spec (except it's only half-greedy: it will not stop at the first
> match, although it won't hit the served-by services if it's
> successful on the primary referenced service) at
>
> http://dc.g-vo.org/ivoidval/q/didresolve/form
>
> This assumes new-style ivoids -- if you already have some of those,
> please give this a whack.
>
> With this, I'd consider Identifiers 2.0 ready for TCG review.
> Objections?
>
> Cheers,
>
>          Markus
>
>


-- 
Dr. Alberto Accomazzi
Program Manager
NASA Astrophysics Data System - http://ads.harvard.edu
Harvard-Smithsonian Center for Astrophysics - http://www.cfa.harvard.edu
60 Garden St, MS 83, Cambridge, MA 02138, USA
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