New version of VO Support Interfaces: v0.26

[Guy Rixon]

Hi,

in view of the cross-WG debate on getting metadata from services, I  
have produced a new version of the VO Support Interfaces spec, which  
you may find at

http://www.ivoa.net/internal/IVOA/IvoaGridAndWebServices/ 
VOSupportInterfacesMandatory-0.26.pdf

In this version I've tried to make the operations compatible with the  
suggested equivalents in DAL and TAP.

The operation that produces VOResources is split into getRegistration  
- that which the service author wishes to put in the registry - and  
getMetadata - all the resources, including those that should not be  
registered. This tries to cover the cases of volatile metadata which  
change too often for the registry to keep up.

The use of VOSI in REST systems is emphasized. In particular, in a  
REST system, the getMetadata and getRegistration operations can be  
implemented as any (HTTP) endpoint that produces the right kind of  
document. Therefore, the author of a DAL service might register,  
e.g.,  http://my.server.edu/dal-service/getCapabilities? 
FORMAT=VOTable, calling out a specific use of the DAL getCapabilities  
operation. Further, the registrationChangedOn and metadataChangedOn  
operations for a REST service are now just the normal HTTP headers  
for the registration and metadata documents; no need to implement  
extra operations and so less work.

I've de-emphasized the SOAP binding for VOSI, but it's still in  
there, unchanged from v0.25.

Normally, I'd suggest these changes on the GWS list before posting a  
new draft. Since we're so close to the Interop, I've taken the  
liberty of posting it anyway. It would be really nice to wrap up VOSI  
in Beijing.

Cheers,
Guy