Re: Serving stale pages

From: Alex Rousskov <rousskov@dont-contact.us>
Date: Mon, 20 Jul 1998 12:45:02 -0600 (MDT)

On Mon, 20 Jul 1998, Rodney Holm wrote:

> I have to try to explain to a customer why a page that has changed is
> being served from the cache and not from the web server.

Good luck!
 
> Am I correct in assuming that it has something to do with the web
> server not sending the Last Modified information or the Expires
> information in the http header.

In most cases, yes. Essentially, if the origin server does not provide enough
information (Cache-Control, Last-Modified, Expires, etc.), Squid has to
guess. As with any guess, it may be wrong. A browser has the same problems
(i.e., they are not proxy specific).

Alex.

P.S. Next time when you send the headers, consider using "client" or "wget"
programs to see the _original_ headers from the site; to be sure Squid is not
dropping something important...

pail> ./client -h www.lightspeed.net -p 80 http://www.lightspeed.net/ | head
HTTP/1.1 200 OK
Date: Mon, 20 Jul 1998 18:37:24 GMT
Server: Apache/1.2.4 FrontPage/3.0.3
Connection: close
Content-Type: text/html
Received on Mon Jul 20 1998 - 11:46:22 MDT

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