Using the AstroRuntime against NVO registry

[Noel Winstanley]

Hi Juan
Thanks for your post.  You ask many perceptive questions, which I'll  
try to answer below.

It may be  best to continue much of this discussion on astro-runtime- 
users at astrogrid.org and off the apps at ivoa.net list -  my  
understanding is that the apps at ivoa.net list is more for standards  
development than user support (however, I'm willing to be corrected  
on this ;) ). However, some of it does seem relevant to  
registry at ivoa.net too.

On 15 Jun 2007, at 15:19, Juan de Dios Santander Vela wrote:

> Hi, I'm trying to attach VO capabilities to an existing spectral  
> manipulation Java application, and I'm using the Astro Runtime for  
> that.
>
> My problem is that if I try to recover how many SSA services exist,  
> I obtain just 14 --with some of them not properly working--, but if  
> I query the NVO, I get as many as 22.
>

ok.  I can confirm this - I did the following in python (xmlrpc  
interface to AR).

 >>> q = s.ivoa.ssap.getRegistryAdqlQuery()
 >>> q
"Select * from Registry where  @xsi:type like '%SimpleSpectrumAccess'  "
 >>> len(rs)
14

So, get 14 results.

As for some of these services not properly working - this is a pity,  
and rather out of our control - it is up to the individual service  
providers to correct. You see the same behaviour when querying for  
spectra in AstroScope. Once the new registry schema (1.0) gets  
deployed, we should be able to use the new 'validationLevel'  
attribute to filter out the low-quality services.

As for the missing services - It's possible that the default  
astrogrid registry (which AstroRuntime queries against by default)  
isn't harvesting all that it should.

Can you give me details of which NVO registry you're looking at? Then  
we can make sure that the astrogrid registry is synchronized with it.


> There are methods from the ivoa.externalRegistry class, that should  
> allow me to query the NVO, but I'm failing by:
>
> a) Not being able to retrieve an appropriate NVO endpoint;
>    maybe the methods in the ivoa.externalRegistry class cannot operate
>    with the SOAP NVO?

I should hope the AR  would work with any IVOA-standard registry.  
However, you need to be aware that many registries do not implement  
the XQuery extensions - and only support keyword or adql-based  
querying. Again, I hope that the registry upgrade will lead to better  
descriptions of what functionalites each registry supports.

If you could give me the endpoint for the NVO registry you're using,  
I'll give it a try myself.


>
> b) Not being able to select whether a registry query uses a REST  
> end-point or
>    a SOAP one?

the IVOA has only standardized a SOAP interface to registries. Rest  
is a good idea, but not standard. Now, if there's sufficient demand  
(and stability) of this interface, I've no objection to adding it to  
AstroRuntime eventually....


>
> Any pointers will be highly appreciated...
>
> ps. While the Registry of Registries gets developed, is there any  
> "registry" that can be considered "the canonical registry", at  
> least for practical reasons?

I don't know the answer to this one. I guess within the UK, we  
consider our registry in Leicester to be the 'uk canonical' registry.  
Maybe Kevin can give a fuller answer to this.

Note that the RofR is only an 'index' of other registires - it does  
not contain any other kind of resources - so, for example, you can't  
use it to query for spectra services, only for other registries.


> Is not registry harvesting fully operational?
>

as far as I'm aware, it's working.

cheers
noel.

> -- 
> Juan de Dios Santander Vela
> Diplomado en CC. Físicas, Ingeniero en Electrónica
> Doctorando en Tecnologías Multimedia
> Becario Predoctoral del Instituto de Astrofísica de Andalucía
>
> Thomas Alva Edison: Una experiencia nunca es un fracaso, porque  
> siempre viene a demostrar algo.
>
>