Caching doubt

Kristian Lyngstol kristian at
Tue Sep 7 13:43:38 CEST 2010

On Tue, Sep 07, 2010 at 08:09:06AM -0300, Jonathan Leibiusky wrote:
> I think I didn't explain myself good enough and after playing with varnish I
> realized that by default varnish won't forward to the backend If-None-Match
> and If-Modified-Since headers.
> Right now my backend is prepared to answer 304 when the resource hasn't been
> modified, so I would like varnish to cache an object for X seconds and after
> that use the ETag and Last-Modified sent by the backend to verify if the
> expired resource is still the same and not ask directly for a fresh one.
> Right now it always asks for a new one.

Jonathan: We should take this on the support-list :)

Anyway: As I said on support@: Varnish supports 304 to the client, but it
does not send conditional GET requests to a web server.

So Varnish will always get the entire object from the web server, but it
will send "304 Not Modified" to the client if the conditional GET request
indicates that the client already has the content.

- Kristian
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