role of the registry

[Paul Harrison]

On 08.05.2007, at 17:53, Robert Hanisch wrote:

>
> The registry was conceived as a resource location service.  The  
> formative
> document describes resource metadata.  The name of the working  
> group is
> Resource Registry.  There has been debate for a long time on how  
> far to push
> the registry in the direction of detailed service-level metadata.  The
> origins were simple, however.  The "radical change to the way the  
> VO works"
> is coming from adding increasing complexity and overhead to a simple
> concept.  This is not unique to the registry, but it is clear in  
> the case of
> the registry that even the simple stuff is not done well or  
> completely.

Adding fine grained metadata to resource records is all about being  
able to find the desired resource more quickly, rather than having to  
do a two stage process of

1. search the registry for resources that might be suitable.
2. query each resource for specialized in turn to see if it is really  
what you want.

It is not a "radical change to the way the VO works", but a practical  
response the the realities of trying to make the VO more efficient.


On 08.05.2007, at 16:51, Aurelien Stebe wrote:
>
> The Registry is not just a cache for any of this information. It  
> was not
> designed with the idea of just being a cache and changing the ideology
> now that the design is done might not be a good idea.

Not just a cache, but that is certainly one of its roles - what are  
all those harvest methods doing then? What about the distinction  
between publishing registries and searchable registries that is  
described in the first section of the Registry Interfaces Standard  
document? The idea of the registry being a cache for other registries  
content is central to the design. It is not a change of ideology to  
want to use the registry as a "cache" for fine grained information  
that would be available from services.

Anyway, I think that we have reached a consensus in this mailing list  
that "fine grained" metadata will automatically be available from the  
services via the getCapability call for automatic insertion in the  
registry, so it is not really a registry issue any more. The issue is  
whether particular services really provide fine-grained enough  
metadata through the getCapability.....

Regards,
	Paul.