Load balancing across applications with nginx

nginx.conf

events {
   worker_connections 1024;
}

http {
   upstream appname {
      server 127.0.0.1:3000;
      server 127.0.0.1:3001;
   }

   server {
      listen 80;
      location /appname {
         proxy_pass http://appname/;
      }
   }
}