이희승 (Trustin Lee) wrote: > 2008-02-12 (화), 11:16 -0700, Mike Heath 쓰시길: >> Eero Nevalainen wrote: >>> Btw, what was the status of DNS resolution in MINA? I remember that at >>> some point DNS resolving used the blocking java API calls. I could >>> imagine that an asynchronous HTTP-client would have to perform a lot of >>> DNS queries(or not, depending on use). Could this become a pithole? >> That's a very good point, Eero. I think blocking DNS lookups could >> definitely be a very big pit hole. Did anything ever come from all the >> asynchronous DNS lookup discussions? >> >> And that's not the only DNS issue. If a DNS returns multiple A records >> for a given host name, most browsers will try to connect to the IP >> address from the first A record. If that fails, they'll try the next IP >> address and so on until the connection succeeds or all of the A records >> have been exhausted. We should support this same behavior in AsyncWeb. > > I thought it's the operating system who decides which A record to use > and it's often random round-robin style. Is there any related > documentation or is it from your experiment? Just curious.
The way Mozilla browsers handle DNS Round Robin is explained here http://www.mozilla.org/docs/netlib/dns.html under the "Round Robin Support" section. > It would be nice to have a built in DNS lookup mechanism in MINA as we > discussed in our previous discussion, but once the domain name is > resolved, it will be cached by the operation system, so it shouldn't be > a big problem in most cases. It will of course be a problem if someone > is writing a web robot or something similar. I do agree that in most cases it won't be a problem. -Mike
