Re: [squid-users] Can we use "no-cache" or "max-age=0" to refresh the cached objects

> Dear all,
>
> We have a Squid (2.6) server installed as a reverse proxy and connected to
> an original-server that uses the "Expire" header field to specify when the
> response should be considered stale.
>
> If the client requests includes a "no-cache" cache-control directive can
> we assume that Squid will be forced to *reload* the cached object with a
> fresh response returned by the original server (assuming that the response
> has a new expiration date set)?
>
> The HTTP header specification
> (http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.9.4) says
> that "the server MUST NOT use a cached copy when responding to such a
> request" but does not say what should happen with the current cached
> object. Would it be replaced by new response?
>
> What would be the behavior of Squid in case of "max-age=0" request
> directive (assuming again that the response has a newer expiration date
> set)?

Squid would request new data, I believe.
Any time Squid receives new files from an authoritative source it updates
its cached copy with the new content (except possibly in cases of bug #7).
A few other things come in to play such as whether its allowed to store
the content returned, Vary, ETag etc.

Amos
Received on Thu Oct 02 2008 - 02:04:52 MDT