FTP Load-Balanced through haproxy

frontend LENS_FTP_COMMAND
	bind			:::21 v4v6
	mode			tcp
	log			global
	timeout client		180000
	default_backend galaxy-ftp_tcp_ipvANY

frontend LENS_FTP_PASV
	mode			tcp
	log			global
	timeout client		180000
	bind :::10000-14000 v4v6
	default_backend galaxy-ftp_tcp_ipvANY

backend galaxy-ftp_tcp_ipvANY
	mode			tcp
	log			global
	timeout connect		30000
	timeout server		30000
	retries			3
	server			galaxy_ftp 10.10.50.50 check port 21 inter 10s

http://www.taitclarridge.com/techlog/2012/09/ftp-load-balanced-through-haproxy.html