nginx.conf :

proxy_cache_path /tmp/cache levels=1:2 keys_zone=my_cache:100m max_size=10g inactive=60m use_temp_path=off;

www.xxx.com.conf:

server {
    ...
    location / {

        #proxy_cache_min_uses 3;
        proxy_cache my_cache;
        proxy_cache_key $host$uri$is_args$args;
        proxy_cache_methods GET HEAD;
        proxy_cache_valid 200 24h;
        proxy_cache_valid any 10m;
        add_header X-Cache-Status $upstream_cache_status; 

        proxy_pass http://localhost:8000;
    }
}