Rack::Pooledthrottle is middleware which provides rate-limiting of incoming HTTP requests to Rack applications. You should be able to use it with any Ruby web framework (I have only tested Sinatra and Rails).

I initially tried to work it into Rack Throttle, but because of Rack Throttle's many backend options I thought it would be too complicated.

So how is it different?

  1. It uses a pool (via ConnectionPool) of connections instead of creating one on each request
  2. It uses a sliding TTL for tracking. This means if you limit an IP to 10 requests every hour and the first request comes in at 1:30 the user can make up to 9 more requests until 2:30.
  3. The TTL is set on middleware declaration. No other subclasses.
  4. Database support is limited to Memcached (and eventually Redis)


Add this line to your application's Gemfile:

gem 'rack-pooledthrottle'

And then execute:

$ bundle

Or install it yourself as:

$ gem install rack-pooledthrottle


Adding throttling to a Rails application

require 'rack/pooledthrottle'
require 'dalli' #Dalli is not required. You must add it to your gem file if you want to use it. 
$mc_pool ||= ConnectionPool.new(size: 5) {Dalli::Client.new}

class Application < Rails::Application
  config.middleware.use Rack::Throttle::Interval, max: 10, ttl: 3600, pool: $mc_pool

Adding throttling to a Sinatra application

require 'sinatra'
require 'rack/pooledthrottle'

use Rack::Throttle::Interval, max: 5, ttl: 60, pool: $mc_pool #see above for pool

get('/hello') { "Hello, world!\n" }    


I just want to make it super clear that a vast majority of this code was based on the excellent work of Rack Throttle.


  1. Fork it ( https://github.com/[my-github-username]/rack-pooledthrottle/fork )
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Add some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create a new Pull Request