worker_processes auto;
worker_rlimit_nofile 65535;

events {
  worker_connections 4096;
  use epoll;
  multi_accept on;
  accept_mutex off;
}

http {
  access_log off;
  error_log /dev/null crit;

  sendfile on;
  tcp_nopush on;
  tcp_nodelay on;

  keepalive_timeout 65;
  keepalive_requests 1000000;

  client_max_body_size 1k;
  client_body_timeout 1s;
  client_header_timeout 1s;

  upstream backend_pool {
    least_conn;
    server api1:9999 max_fails=1 fail_timeout=1s weight=1;
    server api2:9999 max_fails=1 fail_timeout=1s weight=1;
    keepalive 3072;
    keepalive_requests 100000;
    keepalive_timeout 120s;
  }

  server {
    listen 9999 default_server;

    location / {
      proxy_pass http://backend_pool;
      proxy_http_version 1.1;
      proxy_set_header Connection "";
      proxy_buffering off;
      proxy_cache off;
      proxy_store off;
      proxy_connect_timeout 100ms;
      proxy_send_timeout 2s;
      proxy_read_timeout 2s;
      proxy_next_upstream error timeout invalid_header http_500 http_502 http_503;
    }
  }
}