This is an update to the old `gem mirror` command. It uses net/http/persistent and threads to grab the mirror set a little faster than the original. Eventually it will replace `gem mirror` completely. Right now the API is not completely stable (it will change several times before release), however, I will maintain stability in master.
Gemfile gem 'rubygems-mirror', '~> 1.0.1'
install gem install rubygems-mirror