monitor.rb

require 'bundler/setup'
require 'faraday'
require 'typhoeus'
require 'typhoeus/adapters/faraday'
require 'pry'

conn = Faraday.new do |faraday|
  faraday.adapter :typhoeus
end

urls = [
  'https://stackoverflow.com',
  'https://avatars1.githubusercontent.com/u/391331?v=4&s=60',
  'https://rubygems.org',
  'https://www.npmjs.com/'
]

results = {}
urls.each do |url|
  results[url] = []
end

count = 20
print "Running #{count} checks"
count.times do
  conn.in_parallel do
    urls.each do |url|
      results[url] << conn.get(url)
    end
  end

  print "."
  sleep 1
end
puts

results.each do |url, responses|
  failures = responses.select do |response|
    response.env[:typhoeus_connection_failed] || response.env[:typhoeus_timed_out]
  end

  puts "#{url}: #{failures.size}/#{count} failures"
end