nginx caching

[Igor Sysoev]

On Sun, Jul 19, 2009 at 02:54:34AM -0700, Gabriel Ramuglia wrote:

> Hi,
> 
> I've been using nginx for a while now to proxy flv videos via youtube,
> to good effect. However, the site that I'm accessing to proxy videos,
> I'm having problems being able to access their site in bulk, so I've
> decided to start caching things locally so as not to hit the remote
> server so often. I'm doing this in squid, and, for a variety of
> reasons, using the url_rewriter function to help out. My urls change
> every hour, but the video they refer to does not, so I have to use the
> rewriter to make sure the cache stays relevant.
> 
> Now, the problem is, squid is using something like 60% of one core of
> cpu doing something like 200 megabit / s of bandwidth. This is on top
> of the fact that squid has to pass cache misses off to nginx, which is
> using another 20% or so (of one core, again) cpu use. Obviously if I
> could cut squid out of the equation this would be ideal.
> 
> Is there a way in nginx to use the same functionality as the
> url_rewriter in squid? Is there a tutorial or other helpful links on
> doing caching in nginx?

http://wiki.nginx.org/NginxHttpProxyModule#proxy_cache

http {
   proxy_cache_path   /spool/nginx/cache levels=1:2
                      keys_zone=cache:10m
                      inactive=3h;

   server {

       location / {
           proxy_pass   ...;

           proxy_cache            cache;
           proxy_cache_valid      200 24h;
           proxy_cache_use_stale  error timeout invalid_header updating
                                  http_500 http_502 http_503 http_504;

           proxy_ignore_headers   Expires Cache-Control;
       }

As to url_rewriter, it's depend on functionality: you may use simple
"rewrite" or complex "perl_set":
http://wiki.nginx.org/NginxEmbeddedPerlModule


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