On Fri, 10 Aug 2007 12:30:44 +0500 "Shabbir Ahmed" <shabbir@xxxxxxxxxx> wrote: > > i would like to know how squid replaces old items in cache by default. > > like there isa site called abc.com squid cached it today and next day > abc.com made some changes what is the criteria squid ll cache changes > and users ll get the newer pages. > When a client requests an object, squid looks at the object's expiry time to determine whether it's stale or fresh. If there isn't an expiry time a set of rules are used instead. Fresh objects are fetched out of cache. If an object is stale, a conditional request is made to the webserver, which replies either with a new version of the object, or a code saying the exiting object is still valid. It's also possible for browsers to force an update, or force a check for updates.
