http {
    upstream myproject {
        server 127.0.0.1:8000 weight=3;
        server 127.0.0.1:8001;
        server 127.0.0.1:8002;    
        server 127.0.0.1:8003;
    }

    server {
        listen 80;
        server_name www.domain.com;
        location / {
            proxy_pass http://myproject;
        }
    }
}