- From: Ho John Lee <hjl@hplb.hpl.hp.com>
- Date: Thu, 05 Dec 1996 23:45:28 PST
- To: mogul@pa.dec.com
- Cc: http-wg%cuckoo.hpl.hp.com@hplb.hpl.hp.com
> However, I think everyone agrees with you that it's both possible and > desirable for origin servers to explictly mark all responses > as either non-cachable or cachable, since then the proxies don't > have to play guessing games based on the URL. E.g., if you are > writing a server that uses CGI or "?" URLs, and you know that > some of these are cachable, if you simply add a Last-Modified > or Expires (in the future) header to the response, then a well > designed proxy will cache the response. Conversely, if you > mark the response as Expires "in the past", then no well designed > cache should cache it (without at least sending you a conditional > GET to see if the value has changed). Do you know offhand which proxies currently interpret the Last-Modified header in a way that would cache CGI/"?" URLs? The interactive imaging protocol we're currently developing *should* be cacheable, as the image tiles being sent don't change, and the initial image view will generally be the same each time it's requested. It would be nice if we could get *some* systems to cache something while we work out a better scheme for making the rest of the tile information cacheable by proxies. --hjl
Received on Thursday, 5 December 1996 23:53:09 UTC