Ping a URL and report 95th percentile timings

Gemfile

gem 'smart_colored', :require => 'smart_colored/extend'
gem 'rest-client'

restping.rb

#!/usr/bin/env ruby
require 'rubygems'
require 'bundler'
Bundler.setup
Bundler.require
require 'pp'
interval = 1.0
url = ARGV.pop
@format = "%.4f"
@timings = []
def stats
  STDERR.puts <<-EOF

  95%: #{ @format % (@timings.sort[((@timings.count  * 0.95).ceil)-1]) }
  Avg: #{ @format % (@timings.inject(:+) / @timings.count) }

  EOF
end
Signal.trap("INT") do
  stats
  exit
end
Thread.new do
  loop do
    sleep 30
    @timings = @timings.pop(1000)
    stats
  end
end
loop do
  start = Time.now
  response = RestClient.get(url){|response, request, result| response }
  latency = Time.now - start
  @timings << latency
  graph = " ".inverse * Math.log(latency * 100)
  code = case response.code.to_i
  when 0
    graph = graph.red
    response.code.to_s.red.on_white
  when 100..400
    response.code.to_s.green_bold
  when 400..500
    graph = graph.blue
    response.code.to_s.blue_bold
  when 500...600
    graph = graph.red
    response.code.to_s.red.on_white
  else
    response.code.to_s.green_bold
  end
  puts [ @format % latency, code, graph ].join " "
  if interval > latency
    sleep interval - latency
  end
end