[PATCH] Upstream: add $upstream_cache_age variable

[Maxim Dounin]

Hello!

On Mon, Oct 06, 2014 at 02:10:18PM +0400, Roman Arutyunyan wrote:

[...]

> Another issue i’ve found reading the RFC.
> 
> If the reason for $upstream_cache_age is adding HTTP Age response header then it makes
> sense to improve age calculation algorithm.
> 
> According to RFC 7234 / 4.2.3. "Calculating Age” the local cache age should be added
> to the Age value received from backend (“age_value").
> 
> response_delay = response_time - request_time;
> corrected_age_value = age_value + response_delay;

I agree, I don't think that the "date" value as stored in the 
cache can/should be used for Age header.  And I doubt it should be 
exposed as a variable at all, even if calculated properly.

-- 
Maxim Dounin
http://nginx.org/