RE: Hosting Failover Question

Ideally, I wouldn't find any kind of "session" to time out. Almost everyone is fine with short outages (few seconds) as long as their apps don't time out. While 5 seconds is great, I think you'll have a hard time getting there. You'll have to exchange tons of "hello" type packets which means you're flooding a lot of traffic. You can control it at ports, but it's still a pain.