On tor, 2008-06-05 at 23:53 +0800, howard chen wrote: > 1. I found that if a file only has LM being sent out, the browser > seems to cache the file forever and won't request the server until you > press F5, is it true? Browser caches is quite often very agressive and only checks for modification once per browsing session. > 2. Squid will not cache for a file if expire has not been set, is it true? False. If there is no freshness assigned to the object Squid uses refresh_pattern to calculate one basedon Last-Modified. > 3. The prioiry of client sending cache-control, max-age=0 is higher > than IMS and must force contacting the backend to refresh (i.e. not > 304 but 200). max-age=0 instructs caches to query the next hop to verify freshness using a conditional query (i.e. If-Modified-Since). Which means thata GET with max-age=0 will be transformed into an If-Modified-Since query by Squid if the object is cached. no-cache says that the cache should not be used. Regards Henrik