A note on naming www services

Mitchell N Charity (mcharity@hq.lcs.mit.edu)
Tue, 11 Jan 94 18:57:55 EST

When creating a new www "service", it can be useful to reflect the
service name in the "path", in addition to reflecting it, as is
customary, in the DNS "host"name.

Suppose you are announcing a new www service, which is running on a
machine mydesk.cs.nowhere.edu . People used to announce the service as
http://mydesk.cs.nowhere.edu/ .

This has the recognized problem that you may someday wish to use a
different machine. So the convention has developed of creating a DNS
alias or pointer. Thus you might announce http://www.cs.nowhere.edu/ .

But a related problem is NOT addressed by this solution:
It is not posible to transparently move two services,
begun on different servers, to a single server.

For service identity is being uniquely determined by the DNS name,
as a server receiving a connection does not know the name(s) which
the client resolved to find the server's IP address.

Adding service identity to the "path" addresses this problem.
One might announce http://www.cs.nowhere.edu/www-cs/ .
This allows you to later, transparently, let the server providing
http://www.nowhere.edu/nowhere/ to also provide your service.
And lets you run take over the experimental
http://mumble-www.cs.nowhere.edu/mumble/ .