How to sort parameters in nginx cache key

[Valentin V. Bartenev]

On Tuesday 16 September 2014 14:32:41 Wei Chen wrote:
> Hi:
> 
> We are experiencing low cache hit ratio in Nginx server. It turned out
> that one reason is client may be sending the same requests with
> parameters in different orders.
> 
> e.g.
> 
> foo?p1=a&p2=b&p3=c
> foo?p2=b&p1=a&p3=c
> 
> And our cache key is set as
> proxy_cache_key $uri$is_args$args;
> 
> It is not feasible to change all clients to resort their urls. Is
> there any way in Nginx to address that?
> 

You can sort them manually:

   proxy_cache_key $uri$is_args$arg_p1&$arg_p2&$arg_p3;

 wbr, Valentin V. Bartenev