495884965

http://wiki.nginx.org/NginxHttpUpstreamModule#.24upstream_response_time
https://rtcamp.com/tutorials/nginx/upstream-cache-status-in-access-log/

https://rtcamp.com/tutorials/nginx/log-parsing/

log_format rt_cache '$remote_addr - $upstream_cache_status [$time_local] ' '"$request" $status $body_bytes_sent ' '"$http_referer" "$http_user_agent"';

log_format x1 '$remote_addr $upstream_addr $remote_user [$time_local] ' '"$request" $status $bytes_sent $request_time $upstream_response_time' '"$http_referer" "$http_user_agent" "$gzip_ratio"';

request_time ：This shows how long Nginx dealt with the request
upstream_response_time ：Gives us the time it took our upstream server (in this case Apache/mod_wsgi) to respond