Best nginx configuration for rails and passenger

nginx.conf

worker_processes  2;
worker_rlimit_nofile 100000;
error_log  /home/cdeploy/error.log;

events {
    worker_connections  768;
    use epoll;
    multi_accept on;
}

http {

    passenger_root /home/cdeploy/.rvm/gems/ruby-2.0.0-p643/gems/passenger-5.0.6;
    passenger_ruby /home/cdeploy/.rvm/gems/ruby-2.0.0-p643/wrappers/ruby;

    include       mime.types;
    default_type  application/octet-stream;

    sendfile on;
    keepalive_timeout  30;
    tcp_nopush on;
    tcp_nodelay on;
    open_file_cache max=50000 inactive=20s;
    open_file_cache_valid 30s;
    open_file_cache_min_uses 2;
    open_file_cache_errors on;
    reset_timedout_connection on;
    client_body_timeout 10;
    send_timeout 2;
    large_client_header_buffers 4 256k;
    limit_conn_zone $binary_remote_addr zone=conn_limit_per_ip:10m;
    limit_req_zone $binary_remote_addr zone=req_limit_per_ip:10m rate=30r/s;
    limit_conn conn_limit_per_ip 20;
    limit_req zone=req_limit_per_ip burst=20;

    server {
        listen       80;
        server_name  54.207.84.57;

        root /home/cdeploy/teaser/public;
        passenger_enabled on;

        limit_conn conn_limit_per_ip 30;
        limit_req zone=req_limit_per_ip burst=10 nodelay;


        location ~/img {
       		limit_conn conn_limit_per_ip 999;
        	limit_req zone=req_limit_per_ip burst=999 nodelay;
        }
 
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }
    }
        client_body_buffer_size 128k;
}