Re: Some data related to the frequency of cache-busting
Andrew Daviel (andrew@andrew.Triumf.CA)
Wed, 4 Dec 1996 16:26:34 -0800 (PST)
Why can't (shouldn't) one cache a CGI response ? It seems to me more
rational to flush cache based on the frequency of hits. For example, the
"help" page at altavista is CGI-generated from a query, but as far as I
know it's static. It's perfectly reasonable to generate static pages
from a database using CGI or otherwise, and it's quite possible to
set all the headers Last-Modified, Expires, Content-Length etc. in
an appropriate manner. I use a Squid cache set to reject "/imagemap"
and not much else (though not to pass cgi-bin or ? to the parent).
Perhaps 5% of queries are cache hits, compared to around 16% of images.
If someone looks up "Soccer in Latvia" in a search engine, is it really
going to change in ten minutes? A day? More so than
http://www.obscure.org/some/really/obscure/page.html ?
Re. charsets, content negotiation, etc in HTTP 1.0 - I decided
as a compromise that using a redirect CGI is "mostly harmless".
True, if the origin server can't be reached you're stuck, but the
big text files can be cached. I think Microsoft's doing something like
this, but as someone pointed out to me, they use set-cookie with a path
of / which strictly speaking makes the whole site uncacheable.
Andrew Daviel mailto:advax@triumf.ca
http://vancouver-webpages.com/CacheNow/ - campaign for Proxy Cache