I'm rather surprised to see rack-jruby up as high as it was. I discounted ruby as an option for a very high performance http service, but I guess I'd be wrong to do that. Don't get me wrong, I love ruby and I use it every day. I just didn't expect to see it in the top performance contenders list.
That is principally thanks to TorqBox, the codename for Torquebox 3, which is built on Undertow. Undertow is the web server that is scrapping with Netty and Vert.x on the plaintext tests.
Also note that the particular Rack test that performs very well is running a very small amount of Ruby code. Thanks to these improvements, however, rails-jruby now consistently tops rails-ruby, if only by a small amount.
