----- "Tony Anecito" <adanec...@yahoo.com> wrote: > Hi Tom, > > So for the If-Last-Modified header it has to go all the way back to > the origin > server and not stop at the browser cache or proxy server correct? The > Proxy does > not periodically (async) check the origin server? Whereas for the
This highly depends on the Proxy (Cache) in question. > Expires header > it will not go to the origin server but rather than the browser or > proxy if the > time has not expired for that file. > > Thanks for the prompt reply. > -Tony > > > > ----- Original Message ---- > From: Tom Evans <tevans...@googlemail.com> > To: users@httpd.apache.org > Sent: Wed, February 2, 2011 10:47:41 AM > Subject: Re: [users@httpd] Browser, Apache and caching... > > On Wed, Feb 2, 2011 at 5:06 PM, Tony Anecito <adanec...@yahoo.com> > wrote: > > Hi All, > > > > I am wondering for the browser cache to work does the expires > headers in the > > apache config file have to be setup? Or by default when the page > request from > > the browser hits apache does it look at the file modified time stamp > for the > > file on disk or Apache cache and compares to whatever the request > has in it (I > > assume a file timestamp)? > > > > Just trying to figure out if expires header is really needed because > if you > use > > it by setting a future date then the only way to get the file sent > across due > >to > > some change is to rename it slightly. > > > > Thanks, > > -Tony > > > > Correct, sending an Expires header will make UA caches store the > object unconditionally until it gets ejected or the date specified is > reached. > > Instead of sending Expires, if you send a Last-Modified header (which > will happen by default for files served from disk by Apache), then the > next time the UA requests that, it should add a header > If-Modified-Since header. If the file hasn't been modified since that > time, then Apache will send an empty 304 response (Not Modified), and > the UA will serve from cache. > > Cheers > > Tom > > --------------------------------------------------------------------- > The official User-To-User support forum of the Apache HTTP Server > Project. > See <URL:http://httpd.apache.org/userslist.html> for more info. > To unsubscribe, e-mail: users-unsubscr...@httpd.apache.org > " from the digest: users-digest-unsubscr...@httpd.apache.org > For additional commands, e-mail: users-h...@httpd.apache.org > > > > > --------------------------------------------------------------------- > The official User-To-User support forum of the Apache HTTP Server > Project. > See <URL:http://httpd.apache.org/userslist.html> for more info. > To unsubscribe, e-mail: users-unsubscr...@httpd.apache.org > " from the digest: users-digest-unsubscr...@httpd.apache.org > For additional commands, e-mail: users-h...@httpd.apache.org -- Igor Galić Tel: +43 (0) 664 886 22 883 Mail: i.ga...@brainsware.org URL: http://brainsware.org/ --------------------------------------------------------------------- The official User-To-User support forum of the Apache HTTP Server Project. See <URL:http://httpd.apache.org/userslist.html> for more info. To unsubscribe, e-mail: users-unsubscr...@httpd.apache.org " from the digest: users-digest-unsubscr...@httpd.apache.org For additional commands, e-mail: users-h...@httpd.apache.org
