scaling

For best scalability, you will want to run multiple thin servers. Instead of starting the application with rackup, try thin -s4 -p 5000 start (or similar) instead.

nginx

Once we're running more than one thin server, let's use nginx to proxy those requests to localhost for us:

user www-data;
worker_processes  4;

error_log  /var/log/nginx/error.log;
pid        /var/run/nginx.pid;

events {
    worker_connections  4096;
}

http {
    include       /etc/nginx/mime.types;
    access_log	/var/log/nginx/access.log;

    sendfile        on;
    keepalive_timeout  65;
    tcp_nodelay        on;

    gzip  on;
    server {
        server_name maps.example.com maps1.example.com; 
        listen 80;
        location / {
            proxy_pass http://127.0.0.1:5000; 
        } 
    }
    server {
        server_name maps2.example.com;
        listen 80;
        location / {
            proxy_pass http://127.0.0.1:5001;
        }
    }
    server {
        server_name maps3.example.com;
        listen 80;
        location / {
            proxy_pass http://127.0.0.1:5002;
        }
    }
    server {
        server_name maps4.example.com;
        listen 80;
        location / {
            proxy_pass http://127.0.0.1:5003;
        }
    }

}