Discover and publish a server's functionality

-- Name --

Generically discover and publish a server's functionality

-- Description --

Abelard, an independent publisher of web publications, often needs to query
an arbitrary list of RDF storage servers for assertions about a set of URIs
he cares about. The RDF storage servers are RSS feed aggregators. The set of
URIs identify Abelard's web publications. Abelard wants to use RDF to keep
track of the things people say in weblogs about his publications.

Abelard's client software includes support for three different query
languages. Abelard's client software connects to each RDF storage
server and determines whether it supports one of the three query
languages it knows about. Abelard's client software chooses, based on
priorities set by Abelard, to send different queries to different
servers.

Heloise, an aggregator of RSS feeds, publishes RDF (extracted from RSS
feeds) on the Web using an RDF storage server. Heloise's server
supports several RDF query languages.

Heloise's server publishes its supported query language available in a
machine readable form. It negotiates with clients in order to choose
the most appropriate query language that they have in common.

-- Value --

Abelard can use software to automate the process of tracking the things
people say on the Web about his publications. Abelard can formulate queries
in a variety of query languages, which preserves his existing investment.
Abelard's software vendor and Heloise's software vendor can develop and sell
extensible, relatively generic systems.

Abelard and Heloise are able to exchange third party data in an
interoperable fashion without requiring out-of-band, human negotiation about
capabilities.

-- Other --

Rather than writing several parallel use cases just like this one, I
invite the reader to substite the following for "query languages" in
this use case:

     * RDF serialization types
     * context support
     * publicly available models with read access
     * publicly available models with write access

Received on Thursday, 18 March 2004 13:40:13 UTC