proxy_cache - how to change expires ?

[Igor Sysoev]

On Thu, May 13, 2010 at 09:51:37AM +0200, Cédric Jeanneret wrote:

> Hello!
> 
> I'm using nginx as a proxy-cache for OSM tiles. My problem is this
> sentence in documentation :
> """The cache honors backend's Cache-Control, Expires, and etc since
> version 0.7.48"""[1]
> 
> I saw that we're supposed to be able to override some headers, like
> "expires" with proxy_ignore_headers[2], but it doesn't seem to work.
> 
> OSM has an expires set to 3 hours. I'd like to keep tiles for 5 days, so I have:
>   proxy_ignore_client_abort on;
>   proxy_ignore_headers "Expires" "X-Accel-Expires";
>   proxy_cache_valid  200 302  7d;
>   proxy_cache_valid  404      1m;
> 
> But it seems my cache is really reseted each 3 hours (for now there
> isn't many traffic on this vhost, it's just a proof of concept for a
> client).
> 
> Did I miss something in the documentation ? if so, what ?
> Maybe I don't use the right configuration, too. Any hints ?

nginx sets an expiration time at the moment when a response is cached.
If you did not ignore the headers some time ago, previously cached
responses will be valid for 3 hours only. New responses should be
cached for 7 days.


-- 
Igor Sysoev
http://sysoev.ru/en/