cache based on file size

[Maxim Dounin]

Hello!

On Mon, Aug 05, 2013 at 10:28:31PM +0000, Johns, Kevin wrote:

> Hi,
> 
> In looking over Nginx configuration for the proxy module, I do not see an easy way to influence what is cached based on object size. I have two use cases of interest:
> 1. Store a small file in a particular zone (e.g., SSD), and
> 
> 2. Have a large file bypass the cache (no-store large files)
> 
> Any insight on how best to accomplish this would be greatly appreciated.

The proxy_no_cache with appropriate variables (e.g., map'ed or 
produced with embedded perl from $upstream_http_content_length) 
might be usable.

E.g. the following should disable caching of responses larger than 
999 bytes or with content length not known:

    map $upstream_http_content_length $toolarge {
        default    1;
        ~^\d\d\d$  0;
    }

    proxy_no_cache $toolarge;

(Untested.)

See http://nginx.org/r/proxy_no_cache for details.

-- 
Maxim Dounin
http://nginx.org/en/donation.html