roadmap

[Pierre Fernique]

Hi Tony,

 > Has the NVO project (or anyone else) built or prototyped any way in which
 > users can submit a registry query (in whatever form) and have the 
resultant
 > services (even if only data services) automatically invoked? - including
 > AstroGrid data services, VizieR services etc? If so, can you point us 
to it
 > - would help to be able to see how this works.
 >

Yes, there is. Actually the AVO prototype is based on Aladin, itself 
based on a registry system: the GLU. I recall briefly its current 
functionalities (sorry for those who already know them):
- distributed registry based on a hierarchical structure (such as the DNS).
- it implements pull and push update methods (quick updates)
- possible local cache for quick resolutions (a few milliseconds per 
resolution) or proxy resolutions to avoid any local installation.
- it manages mirror server sites (detection of the nearest sites)
- it converts automatically the query parameters if it is required

The specific GLU client "Aladin" implements specifically :
- dynamical integrations of news data providers for which the forms are 
generated on the fly according to the published GLU records.
- the management of two kinds of CGI servers:
	. any "one shoot" image or catalog servers (ex: cone search
           servers...)
	. "two shoots" images servers (selection list and real query,
	   ie SIA or IDHA servers)
	
What is not managed by Aladin/Glu client:
- SOAP access servers (even if the GLU describes already SOAP base URLs 
for services, Aladin does not use it: it requires a step of compilation 
on the client side avoiding simple and real dynamic integration (to 
convert the WSDL to the client stub interface)).
- Complex "two shoots" catalog servers. In fact, it misses an equivalent 
of SIA or IDHA standards for catalogs. Actually, Aladin uses the old 
AstroRes format to do that for VizieR access.

What is planned for the next Aladin version:
- dynamic integration of remote processes such as Xmatch servers or 
sextractor servers via GLU records

We are also looking to integrate a light SOAP client dealing with data 
bases having only WS access. About that, in your question, you speak 
about AstroGrid data services. I suppose these are pure WS. I would have 
a great interest to try to "plug" some of them into Aladin by this light 
SOAP client. Do I have to implement an full OAI client to get the 
AstroGrid data service list ? Or do you have a simplest way to get it ? 
Are there prototype services or real services ?

Regards,
Pierre Fernique