The myth of unicorn
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The document discusses the architecture and performance considerations of different Ruby web servers, specifically Unicorn, Thin, and Puma. It emphasizes that Unicorn is optimized for CPU/memory-intensive applications but may not be ideal for all use cases, while Thin offers non-blocking capabilities and Puma introduces a thread pool for improved concurrency. Additionally, it highlights the importance of considering thread safety and the overall speed impact of web servers on request processing.
![Asynchronous Rack?
require 'em-http-request'
app = -> env do
http = EM::HttpRequest.new("http://www.google.com").get
http.callback do
env['async.callback'].call([200, {}, http.response])
end
throw :async # read: yield
end
run app
(demo)](https://image.slidesharecdn.com/rugbtalk-151002124706-lva1-app6892/85/The-myth-of-unicorn-10-320.jpg)
The myth of unicorn
- 1. The myth of unicorn @isaiah_peng
- 2. What is a slow client
- 3. Request queue • Put a nginx before your unicorn • Profit!
- 4. Profit? • unicorn is not suited for all applications. unicorn is optimized for applications that are CPU/ memory/disk intensive and spend little time waiting on external resources (e.g. a database server or external API) — The philosophy of unicorn
- 5. EventMachine / Thin • Asynchronous IO, but • Everything you do by default in Rails is blocking.
- 6. What’s the advantage compared to unicorn? * Non blocking (partly) class Thin::Connection < EM::Connection # When the request is received and parsed def receive_data(data) # anything happening here is blocking resp = @app.call(Request.new.parse(data)) # handoff to EventMachine, non-blocking send_data resp.body.join(“”) end end * Persistent connection
- 9. Potential problems • Circular request
- 10. Asynchronous Rack? require 'em-http-request' app = -> env do http = EM::HttpRequest.new("http://www.google.com").get http.callback do env['async.callback'].call([200, {}, http.response]) end throw :async # read: yield end run app (demo)
- 11. async_sinatra • Demo (async_sinatra.ru) • Good for normal usage • Test `include Sinatra::Async::Test::Methods` • Doesn’t work with Rack::URLMap, could be fixed though • The middleware has to be registered by the ‘async.callback’
- 12. Thread safety of MRI • Native thread & GIL • Demo (multi_thread.rb)
- 13. Puma • Imagine a variation of unicorn that each worker has a thread pool • Designed for implementation with real thread (Rubinius, JRuby) • Puma still improves MRI's throughput by allowing blocking IO to be run concurrently • Cluster mode for MRI • Thread-safety
- 14. Thread safety of Rails • config.threadsafe! (Before Rails4) • demo (rails.ru) • Rack::Lock (puma cluster mode downgrade to unicorn) Don’t gain much with JRuby / Rubinius
- 15. –Someone on the internet “The speed of the web server doesn’t matter that much, you request spends a very little portion of time in the server.”
- 16. References • http://www.rubydoc.info/github/rack/rack/file/SPEC • http://unicorn.bogomips.org/PHILOSOPHY.html • http://tenderlovemaking.com/2012/06/18/removing- config-threadsafe.html • http://www.rubyraptor.org/how-we-made-raptor-up- to-4x-faster-than-unicorn-and-up-to-2x-faster-than- puma-torquebox/