I guess you didn't warm up the JVM before running the tests, since the Jubilee/Vert.x stack is more heavy than the undertow counterpart, it takes longer for the

I guess you didn't warm up the JVM before running the tests, since the Jubilee/Vert.x stack is more heavy than the undertow counterpart, it takes longer for the JVM to apply the optimisations. I also did some benchmarks for Torqbox and Jubilee, you can find the results here: https://github.com/isaiah/jubilee/wiki/Benchmarks-against-other-jruby-commandline-webservers https://github.com/isaiah/jubilee/wiki/Benchmarks-against-ot... Torqbox won the rack test, and Jubilee out performed in the rails one.