I need an EC2 instance to balance all incoming FTP connections to a list of FTP servers (EC2 instances too). This list will be changed dynamically due to the load of the FTP servers (launch a new FTP server when the FTP servers are overloaded or shutdown a FTP server when the load is low).
What you recommend? a FTP proxy? DNS server? Load balancer?
Note: The FTP servers must support Passive Mode