[Zope-dev] [Caching] Inefficient HTML cache?

[Dominic Hiles]

Dear Dieter,

--On 20 November 2004 10:08 +0100 Dieter Maurer <dieter at handshake.de> wrote:

> We use Apache for caching and observe the following behaviour:
>
>   Apache requests the object from Zope and caches it until
>   the expiration date is reached. From then on, Apache
>   forwards "If-Modified-Since" requests to Zope, Zope
>   responds with an "304" response but without a new
>   expiration date! As Apache does not get new expiration info,
>   it continues to forward "If-Modified-Since" requests for
>   the object. This significantly reduces cache efficiency.
>
> In my view, Zope should include new expiration info in its
> "304" responses.
>
> The CachingManager API may need to be extended, to allow
> the HTTP CacheManager to add information to "304" responses.
>

We've noticed the same behaviour and, for that reason, have avoided using 
the HTTP CacheManager in Zope.  Instead, we handle headers (and 304 
responses) for "standard" pages in the main_template and the rest of the 
caching on Apache (using mod_expires for outbound responses).

+1 for fixing this behaviour.

Dominic