open source load balance and fail over utility for TCP based services

 Crossroads is a daemon running in user space, and features extensive
 configurability, polling of back ends using 'wakeup calls', detailed status
 reporting, 'hooks' for special actions when backend calls fail, and much more.
 .
 Crossroads is service-independent: it is usable for HTTP(S), SSH, SMTP, DNS,
 etc.. In the case of HTTP balancing, Crossroads can provide
 'session stickiness' for back end processes that need sessions, but aren't
 session-aware of other back ends.