I'd like to propose some more infos:
I am currently working on a caching/proxy only server.
This would allow configuring of "forwarders", i.e. intermediate
servers for a hierarchy of caching servers, read only access to caches
and so on ...
Therefor it'll be really nice to have some information about the update
rate of the caching servers like:
"File is up to date for me but I haven't checked for n minutes".
Another problem for this topic:
How do I specify Expires: for e.g. GIF files? Would I have to do this
via server config files?
We currently use a "Expires:" of about 14 days for GIFs, assuming
most of them are icons, which change seldon, if not never.
But with all the weather GIFs and coffee machines :) out there ...
P.S. If you have any proposals what caching servers should be able to do,
drop me a note ...