Puma (web server) The other 2 options, Puma and Unicorn, are like ruby interpreters with a built-in web server. You call them inside a rails project root folder and they will listen the port 80 (or one of your own), wait for web conections, run the rails code and answer to the browser â“ without apache, nginx, or any else. Letâ™s suppose that you have 2 rails projects (sites) that you want to run simultaneously: Shell. Puma is the web server shipped with Mastodon[1] and recommended by the Heroku hosting provider as a replacement for Unicorn.[2]. Deliveroo published a benchmark comparing the two servers and concluded âœPuma performs better than Unicorn in all tests that were either heavily IO-bound or that interleaved IO and CPU workâ, but that Unicorn was still slightly better performing situations where CPU load was the limiting factor.[3]. References[edit]. ^ Rochko, Eugen (13 April 2017). "Scaling Mastodon". Puma is a small library that provides a very fast and concurrent HTTP 1.1 server for Ruby web applications. It is designed for running Rack apps only. What makes Puma so fast is the careful use of a Ragel extension to provide fast, accurate HTTP 1.1 protocol parsing. This makes the server scream without too many portability issues. Quickstart with Bundler. If you are using Bundler, just add Puma to your project's GemFile: gem "puma". Once you've installed your bundle, start Puma by running: bundle exec puma. Puma: A Ruby Web Server Built For Concurrency. Puma is a simple, fast, threaded, and highly concurrent HTTP 1.1 server for Ruby/Rack applications in development and production. Built For Speed & Concurrency. Puma was designed to be the go-to server for Rubinius, but also works well with JRuby and MRI. On MRI, there is a Global VM Lock (GVL) that ensures only one thread can run Ruby code at a time. Puma is an HTTP web server derived from Mongrel and written by Evan Phoenix. It stresses speed and efficient use of memory. Puma is the web server shipped with Mastodon and recommended by the Heroku hosting provider as a replacement for Unicorn. Deliveroo published a benchmark comparing the two servers and concluded âœPuma performs better than Unicorn in all tests that were either heavily IO-bound or that interleaved IO and CPU workâ puma is a multi-threaded high performance webserver written in Ruby. It is new in the market yet it has gained lots of traction. It can be used to server any ruby web app that support rack such as Sinatra or Ruby On Rails. As a first class Ruby project, you could install puma via RubyGems. With Rails 3+ app, simply append to Gemfile: 1. gem 'puma', '~> 2.3.2'. then bundle install. You can now start your app with puma with rails s. You should see output if it is started correctly: 1 2 3 4 5. Puma starting in single mode Puma is a simple, fast, and highly concurrent HTTP 1.1 server for Ruby web applications. It can be used with any application that supports Rack, and is considered the replacement for Webrick and Mongrel. It was designed to be the go-to server for Rubinius, but also works well with JRuby and MRI. Puma is intended for use in both development and production environments..