upstream my_server_pool {
  server 192.168.10.21:80 weight=1 max_fails=2 fail_timeout=30s;
  server 192.168.10.20:80 weight=1 max_fails=2 fail_timeout=30s;
  proxy_cache_path /usr/local/nginx/proxy_temp levels=1:2 keys_zone=cache_one:500m  inactive=1d   max_size=1g;

location /sms {
  proxy_pass http://my_server_pool;
  proxy_set_header Host $host;
  proxy_cache cache_one;
  proxy_set_header X-Forwarded-For $remote_addr;
  proxy_cache_valid 200 10m;
  proxy_cache_valid 304 1m;
  proxy_cache_valid 301 302 1h;
  proxy_cache_valid any 1m;
  proxy_cache_key $host$uri$is_args$args;
}