This would be fine, Doug, if everyone agreed to fully populate the registry
with the necessary information and keep it up to date but many service
providers only want to register the minimum information and have the
registry get the full set of information from the service. In this case
services must know and provide the complete set of registry information. And
since the registries cannot know which services are being fully registered
or not, then every service will have to provide its own complete resource
metadata information.
T.
> -----Original Message-----
> From: Doug Tody [mailto:dtody-at-nrao.edu]
> Sent: 18 May 2006 17:40
> To: Tony Linde
> Cc: voql-at-ivoa.net
> Subject: RE: STAP is the protocol, Skynode and DSA are implementations
>
> On Thu, 18 May 2006, Tony Linde wrote:
> > All services ought to support the getRegistryEntry (or
> whatever it was
> > called) method which, in the case of skynodes, should
> return a fully
> > complete CatalogService entry with all table and column
> information:
> > this is a shortcut way of getting the table/column info
> without having
> > to call the individual metadata methods.
>
> Skipping the issue of Skynode for the moment, lets consider
> calling this query-service-metadata operation something like
> getCapabilities instead, and having it defined by the service
> specification. The idea would be to try to make it
> consistent with a registry service specification, but I am
> concerned about making a versioned service operation defined
> by the service have too much knowledge of registry details or
> versions.
> In principle a service implementation does not even know that
> the registry exists. We should try to make getCapabilities
> compatible with what the registry reuqires but this is an
> *interface* between the service and the registry or any other
> client. Since it is a service operation it should be
> controlled by the service specification, and if necessary the
> code which loads this information into the registry can
> perform a translation.
>
> In the case of a skynode or any other service, interface and
> implementation should be separated and the service should be
> able to describe its capabilities. In the case of a skynode
> that would presumably include table/column info, similar to a
> SIAP service reporting that it has optional query parameters.
>
> - Doug
>
Received on 2006-05-19Z06:30:03