Slow DNS = Rubbish
There’s a CNET story running right now about how slow DNS is the bane of a fast connection. They write:
“We hear stories about carriers spending billions of dollars to build new fiber-to-the-home networks or 3G (third-generation) wireless networks,” said Paul Mockapetris, inventor of the DNS architecture and chairman and chief scientist at Nominum. “But broadband providers should also spend some money adding more DNS capability. Pure bandwidth doesn’t solve the problem if the DNS servers can’t respond quickly.”
However, there’s one simple reason why DNS speeds don’t actually matter: caching. Say that an uncached DNS query takes 250ms:
-bash-3.00$ time nslookup apple.com
real 0m0.227s
Then, for every web domain we browse, we incur a one-time hit of 250ms. It doesn’t matter how many times we visit the site after that–the DNS work is already done and saved for future use. Every now and then, our computers will check to make sure the DNS is up to date, and we won’t notice that minor penalty. As for games, the DNS resolution is the just the barrier to establishing a connection. Once that connection is up, no more DNS is done. And, with threading, as your game is loading in one thread, the DNS can be resolving in another thread, essentially taking up no real time at all; just waiting for the DNS resolver Sockets to unblock.