2011/7/26 Eric Hodel <drbrain / segment7.net>:

> If you are having problems with DNS blocking then require 'resolv/replace' to get non-blocking DNS lookups.  Non-blocking DNS in ruby has been available back to 1.6.

Ruby invokes getaddrinfo() without GVL since 1.9.2.
This means, even without resolv/replace, DNS lookup doesn't block other
threads if the platform have getaddrinfo().
-- 
Tanaka Akira