Re: Annotations, sets, & servers, and redirects

> From liberte@ncsa.uiuc.edu Tue Oct 17 19:59 PDT 1995
> > From: gramlich@riesling.eng.sun.com (Wayne C. Gramlich)
> > > Another way to put this is that annotation hot spots will happen, but
> > > solutions to it are orthogonal to the protocol. 
> > As long as the annotation sets are relatively small and you can
> > build a single server that can meet all requests, I agree with
> > the premise of not exposing the structure of annotation sets.
> Now that I think about it some more, it is not necessary to expose the
> structure of annotation sets in order to achieve the objective of
> distributing the serving of annotations across several servers.
> The orthogonal route of assuming there is a distributed file system
> under the single server does not help the server much since it needs to
> respond to just as many queries.
> The solution I am thinking of is that the first server would inform clients
> that for a particular subset of documents (identified by URLs or URL
> patterns), another server may be contacted directly.  The primary server
> may continue to handle all annotation requests by forwarding them to the
> appropriate server, thus acting as a proxy.  Or it may refuse to respond
> to such requests thus forcing clients to wise up.
> I think this is basically the idea that Wayne was suggesting, and I
> don't see how it exposes the internal structure.

Yes, indeed, the design of my annotation proxy prototype had the
concept of organizing the annotation set into a sorted N-ary tree
of HTML documents.  The N-ary tree could reside entirely on one
HTTP server or it could be structured to span a multitude of servers
to distribute load.  Since the annotation set was just a bunch of
HTML documents, they could easily be cached by caching proxies.
Also, since they were just a bunch of HTML documents, they could
be browsed by any ol' garden variety Web browser.  Do I have code
to prove that it worked?  Nope!  I never got around to that part
of the implementation. :-)  My prototype just used a dumb linear

Two rational people could reach opposite conclusions about whether
the internal structure of an annotation set has been exposed by
this strategy of organizing an annotation set as an N-ary tree of
HTML documents.