Discovering Data Collections Note

[Patrick Dowler]

The other idea I had for aux capabilities was to define a capability
type whose extra metadata was the resource identifier of the real
service, eg:

<capability standardID="ivo://ivoa.net/std/SIA#query-2.0"
   xsi:type="aux:LinkedService">
    <resourceIdentifier> ivo://cadc.nrc.ca/sia </resourceIdentifer>
</capability>

That's probably not much different from the old served-by
relationships in practice, except that it does say what type of
service that is right here (in the DataCollection) which I think means
questions of the form "find data collections like ... with an SIAv2
query interface" would be straightforward queries. It would just
result in a resource identifier for that service rather than
interfaces and accessURLs. It does clobber xsi:type, but since my
concern is having to duplicate metadata about service deployments in
different places I see that as a feature rather than a drawback.

my 2c,

Pat

On 4 November 2016 at 11:47, Patrick Dowler <pdowler.cadc at gmail.com> wrote:
> A coupe of comments on the note:
>
> In the second paragraph of 2.1.2 you have the wrong standardID for SIA
> (should be #query-2.0).
>
> In that same paragraph, the recommendation is to insert "aux" between
> the tag and the version. That effectively means that the fragment is
> now a parseable construct as clients will have to be able insert and
> extract the "aux" nature of the standardID. So at first glance it
> seems preferrable to put the "aux" string at the beginning or the end
> rather than in the middle. I experimented a bit and there are a
> variety of separator characters one can use in a URI fragment without
> breaking a standard URI parser, eg.
>
>
> groovy:000> new URI("ivo://ivoa.net/std/SIA#query-2.0@aux").getFragment()
> ===> query-2.0 at aux
> groovy:000> new URI("ivo://ivoa.net/std/SIA#query-2.0~aux").getFragment()
> ===> query-2.0~aux
> groovy:000> new URI("ivo://ivoa.net/std/SIA#aux~query-2.0").getFragment()
> ===> aux~query-2.0
> groovy:000> new URI("ivo://ivoa.net/std/SIA#aux:query-2.0").getFragment()
> ===> aux:query-2.0
> groovy:000> new URI("ivo://ivoa.net/std/SIA#query-2.0&aux").getFragment()
> ===> query-2.0&aux
> groovy:000> new URI("ivo://ivoa.net/std/SIA#query-2.0*aux").getFragment()
> ===> query-2.0*aux
> groovy:000> new URI("ivo://ivoa.net/std/SIA#query-2.0;aux").getFragment()
> ===> query-2.0;aux
>
> some that are legal but too cumbersome:
>
> groovy:000> new URI("ivo://ivoa.net/std/SIA#query-2.0(aux)").getFragment()
> ===> query-2.0(aux)
> groovy:000> new URI("ivo://ivoa.net/std/SIA#query-2.0[aux]").getFragment()
> ===> query-2.0[aux]
>
> and some that I expected to not be valid and they were not:
>
> groovy:000> new URI("ivo://ivoa.net/std/SIA#query-2.0#aux").getFragment()
> Illegal character in fragment at index 32: ivo://ivoa.net/std/SIA#query-2.0#aux
> groovy:000> new URI("ivo://ivoa.net/std/SIA#query-2.0$aux").getFragment()
> Unknown property: aux
> groovy:000> new URI("ivo://ivoa.net/std/SIA#query-2.0%aux").getFragment()
> Malformed escape pair at index 32: ivo://ivoa.net/std/SIA#query-2.0%aux
>
> As I mentioned in Trieste, I have created ~20 data collections and do
> intend to use this to connect them to services, so +1 on the basic
> idea. I'd like to see it being easier to detect aux capabilities so at
> a minimum the "aux" string should be at the beginning or end rather
> than the middle. I'm less sure if there is value in making it
> separable by specifying a special separator character.
>
> On reading the note, I did consider another option, but will bring it
> up in a separate message.
>
> Pat
>
> On 4 November 2016 at 03:35, Markus Demleitner
> <msdemlei at ari.uni-heidelberg.de> wrote:
>> Dear Colleagues,
>>
>> Also in the name of this WG, I'd like to bring the note on discovering
>> data collections on the road to endorsement.  Among other reasons,
>> Registry Interfaces 1.1 will probably use it in saying how to
>> registry RegTAP registries, so it'd be great if we could get
>> endorsement before RI 1.1 reaches the Exec.
>>
>> With that in view, I've reviewed the note and, in the end, did quite
>> a few changes; below is the volute log since publishing the note (cf.
>> http://volute.g-vo.org/svn/trunk/projects/registry/discovercollections)
>>
>> The change log says, shorter:
>>
>> * Now encouraging extra parameters in access URLs where appropriate.
>> * No longer requiring auxiliary capabilities to be plain vr:Capability.
>> * Updates for depreciation of served-by in VOResource 1.1.
>> * Removed secion on GloTS.
>>
>> Before I submit it to the doc repo (scheduled for 2016-11-11): Does
>> anyone have comments or opinions we should clarify within the WG
>> before going to the TCG?  If you don't want to build the doc
>> yourself, there's a formatted PDF at
>>
>> http://docs.g-vo.org/discovercollections.pdf
>>
>> Thanks,
>>
>>         Markus
>>
>> ------------------------------------------------------------------------
>> r3685 | msdemlei | 2016-11-04 11:23:25 +0100 (Fri, 04 Nov 2016) | 3 lines
>>
>> discovercollections: bumping version.
>>
>>
>> ------------------------------------------------------------------------
>> r3684 | msdemlei | 2016-11-04 11:22:00 +0100 (Fri, 04 Nov 2016) | 3 lines
>>
>> discovercollections: removing section on GloTS.
>>
>>
>> ------------------------------------------------------------------------
>> r3683 | msdemlei | 2016-11-04 11:19:55 +0100 (Fri, 04 Nov 2016) | 3 lines
>>
>> discovercollections: Editorial changes.
>>
>>
>> ------------------------------------------------------------------------
>> r3682 | msdemlei | 2016-11-04 11:00:07 +0100 (Fri, 04 Nov 2016) | 6 lines
>>
>> discovercollections: served-by is deprecated by VOResource 1.1, use IsServedBy
>> in the future.
>>
>> Also, some editorial changes.
>>
>>
>> ------------------------------------------------------------------------
>> r3681 | msdemlei | 2016-11-04 10:40:15 +0100 (Fri, 04 Nov 2016) | 5 lines
>>
>> discovercollections: No longer requiring auxiliary capabilities to be
>> plain vr.Capability
>>
>> (also, some editorial changes)
>>
>> ------------------------------------------------------------------------
>> r3675 | msdemlei | 2016-11-03 16:51:15 +0100 (Thu, 03 Nov 2016) | 4 lines
>>
>> discovercollections: Adding a piece on using in-URL parameters to constrain
>> results to the data collections described.
>>
>>
>> ------------------------------------------------------------------------
>> r3674 | msdemlei | 2016-11-03 16:22:44 +0100 (Thu, 03 Nov 2016) | 4 lines
>>
>> discovercollections: Some editorial changes in preparation for making this
>> an PEN.
>>
>>
>> ------------------------------------------------------------------------
>> r3546 | msdemlei | 2016-09-13 19:54:39 +0200 (Tue, 13 Sep 2016) | 3 lines
>>
>> discovercollections: moved SIA 2.0 aux cap id here from SimpleDALRegExt.
>>
>
>
>
> --
> Patrick Dowler
> Canadian Astronomy Data Centre
> Victoria, BC, Canada



-- 
Patrick Dowler
Canadian Astronomy Data Centre
Victoria, BC, Canada