I'm aware of the issues inherent in load balancing FTP, and throwing in SSL makes it doubly difficult.
Does anyone know of an existing product which does a good job of load balancing RFC4217 FTP/TLS? (also known as FTP/SSL and FTPS)
Note I am not asking about SFTP (SSH's file transfer protocol) -- that is easy to load-balance, but unfortunately not an option I can use.
You might find the mod_proxy module for ProFTPD useful for this; it supports forward and reverse proxying of FTP and FTPS, as well as load balancing (in multiple flavors).
Full disclosure: I'm the author of
mod_proxy
andproftpd
.Would it be possible to set up a Linux system using LVS? I'm not certain if that will work with TLS but I know because it runs at the transport layer it would work for FTP.
Take a look at Wikimedia and how they are using it for proper SSL web traffic load balancing.
Take a look to HAProxy, it maybe is not able to track data connections as related to the global FTP session, but you can trick the FTP protocol config in order to provide connection consistency within the session.