Re: Mirror Negotiation

On Tue, 10 Dec 1996, Chanda Dharap wrote:
> Has anyone given thought to some sort of a hierarchy of caches ? Maybe
> topical caches as opposed to regional ? Caching could be a combination
> of server-side Proxy caching as well as caching at the hierarchy.

This is maturing rapidly. CHOICE in Europe, NLANR in the US, JANET in the UK,
several organisations in Japan, New Zealand, Australia etc. all support
hierarchical cache. See http://vancouver-webpages.com/CacheNow/ for
a list of links and some general propaganda.

In a hierarchical cache scheme, the browser asks the first proxy for
a page. Netscape Navigator, for instance, can have a list of proxies
and falls over to direct mode if they are all broken. The first level
proxy either returns the page, or contacts one or more parent
or neighbour proxies if it doesn't have it. Work is ongoing to
make sensible decisions on the most approprriate parent to contact
based on hops, network loading, etc.

Other work in this area includes the URN effort by the HTTP community, 
plus the hierarchical database efforts of the Whois++/find group.

HTTP 1.1 supports multiple locations for a Redirect (well, 1.0 does,
but some browsers break on status code 300.)


Andrew Daviel

mailto:andrew@vancouver-webpages.com 
http://vancouver-webpages.com  : home of multisearch, META generator etc.

Received on Tuesday, 10 December 1996 16:54:50 UTC