Using OOBGC with Unicorn along with a UnicornKiller that kills workers if they use too much memory

gistfile1.rb

#--- Credit: http://kzk9.net/unicorn-configuration-on-heroku

# config.ru

# This file is used by Rack-based servers to start the application.

require ::File.expand_path('../config/environment',  __FILE__)

# Unicorn self-process killer

require ::File.expand_path('../lib/unicorn/unicorn_killer',  __FILE__)
use UnicornKiller::MaxRequests, 10240 + Random.rand(10240) #adjust as required
use UnicornKiller::Oom, 96 * 1024 + Random.rand(32) * 1024 #adjust as required

# Out-Of-Band GC
require 'unicorn/oob_gc'
use Unicorn::OobGC

run App::Application


#-------------

# lib/unicorn/unicorn_killer.rb
# from https://gist.github.com/1258681

module UnicornKiller
  module Kill
    def quit
      sec = (Time.now - @process_start).to_i
      warn "#{self.class} send SIGQUIT (pid: #{Process.pid})\talive: #{sec} sec"
      Process.kill :QUIT, Process.pid
    end
  end

  class Oom
    include Kill

    def initialize(app, memory_size= 512 * 1024, check_cycle = 16)
      @app = app
      @memory_size = memory_size
      @check_cycle = check_cycle
      @check_count = 0
    end

    def rss
      `ps -o rss= -p #{Process.pid}`.to_i
    end

    def call(env)
      @process_start ||= Time.now
      if (@check_count += 1) % @check_cycle == 0
        @check_count = 0
        quit if rss > @memory_size
      end
      @app.call env
    end
  end

  class MaxRequests
    include Kill

    def initialize(app, max_requests = 1000)
      @app = app
      @max_requests = max_requests
    end

    def call(env)
      @process_start ||= Time.now
      quit if (@max_requests -= 1) == 0
      @app.call env
    end
  end
end