Also what are you talking about? If the connection is closed, how would it be used?
Connections should only be closed due to? Inactivity. If a connection is closed, don't you think you would probably want to do another DNS request?
Also if your doing proper layer 4 load balancing using BGP, DNS is a moot point...
Magic...
Or if the user closes the browser of if the server/proxy restarts. But yes, mostly inactivity on the order of a couple of minutes.
> If a connection is closed, don't you think you would probably want to do another DNS request?
That's the whole point of the DNS TTL, to say how long to go before doing another lookup rather than doing it each time you reconnect.
> Also if your doing proper layer 4 load balancing using BGP, DNS is a moot point...
BGP load balancing operates on layer 3, and is irrelevant as you still need to DNS lookup an anycast address. EDNS client subnet is better anyways.
I hope you didn't pay for your education.
By that logic BGP is a layer 7 load balancer since it has an application layer. BGP only exchanges layer 3 reachability information to update route tables therefore you can only load balance layer 3 with it.
Personal attacks and other things in your comments are against the HN guidelines. The goal is to talk about DNS/TTLs and their impact on performance not insult each other. https://news.ycombinator.com/newsguidelines.html