Nginx cached page returning binary data(.gz file) every now and then. Works when cached folder is deleted

[Maxim Dounin]

Hello!

On Wed, Dec 28, 2011 at 08:44:07PM +0530, Quintin Par wrote:

> I have an nginx server running as a proxy. A page from it is
> configured to be cached and served compressed.
> But then every now and then it serves the page as .gz file which shows
> as up a file to be downloaded. A curl –I hit returns binary data.
>   curl -I www.site.com/cs
> But when I deleted the cache folder everything starts working fine.
>   sudo rm -r /tmp/nginx/cscache/
> What could be wrong? Can someone help?
> 
> This is the config
>   location = /cs {
>   proxy_pass http://localhost:82;
>   proxy_set_header   Host             $host;
>   proxy_set_header   X-Real-IP        $remote_addr;
>   proxy_ignore_headers Set-Cookie;
>   proxy_ignore_headers Cache-Control;
>   proxy_ignore_headers Expires;
>   proxy_ignore_headers X-Accel-Expires;
>   add_header X-Cache-Status $upstream_cache_status;
>   proxy_cache             cscache;
>   proxy_cache_bypass       $http_cs;
>   proxy_cache_key         $request_uri;
>   proxy_cache_valid       200 302 1d;
>   proxy_cache_valid       404      1m;
>   proxy_cache_use_stale   error timeout invalid_header;
>   }

Most likely your backend gzips responses (if client supports 
gzipp), and these are getting cached.

Possible solutions include disabling gzipping on backend or 
clearing Accept-Encoding header on nginx side before passing 
request to backend, i.e.

    proxy_set_header Accept-Encoding "";

Maxim Dounin