Re: Uniform access to ...

On May 8, 2008, at 9:53 PM, Booth, David (HP Software - Boston) wrote:

> A quick comment on the 8-May-2008 draft of
> I don't think the POWDER use case as written motivates the need for  
> "uniform access to metadata" very well, because the metadata is  
> both generated and consumed by the server, so the server can just  
> coordinate with itself about where to find the metadata.  I think a  
> much more compelling case would be if the *client* (or perhaps a  
> filtering proxy) needed to consume the POWDER metadata.

Maybe it wasn't clear that there are two servers involved. I've  
changed "server" to "gateway" in the description (and for consistency  
changed "proxy" to "gateway" in the mobile web use case), but we can  
be still more specific that the metadata comes from an origin server  
and is used by the gateway.

I'm also struggling with choice of term X in "uniform access to X".
   - metadata
   - "information pertaining to a resource"
   - links
   - properties
   - links and properties
   - side information
   - descriptions
etc. To cover all the use cases the term needs to  be quite broad  
(e.g. "descriptions" is too narrow, as is "metadata"), but something  
short would be nice. For now I'm just using "metadata" hoping that  
the reader will go along with me in interpreting it broadly and that  
the fact that we're using it in one use case for descriptions of non- 
information things isn't too confusing. (Strictly speaking "metadata"  
is data about data, not data about arbitrary things. The latter would  
be called "description" or "data" or "information".)

The specification of scope is further confused by the fact that "call  
by reference" is an option - you can specify either a single property/ 
link giving the location of further properties (metadata), or you can  
specify the further properties themselves directly, with the choice  
more or less arbitrary. In one case the metadata is the metadata, and  
in another it's a link to further metadata. Which  of these is chosen  
will depend on the mechanism available (Link: and MGET being quite  
different) and on server whim. I don't think I'm confused about this,  
but it is a rhetorical annoyance.


Received on Friday, 9 May 2008 12:08:21 UTC