measure speed of HTTP GET at any particular site.

speed.rb

require 'net/http'
require 'uri'

url = URI.parse(ARGV[0])
http = Net::HTTP.new(url.host, url.port)
path = url.path != '' ? url.path : '/'
path += url.query ? "?#{url.query}" : ""

secs = []

http.get(path) # drop first access

10.times { |i|
  start = Time.now
  result = http.get(path)
  finish = Time.now
  secs << finish - start
  unless result.code == "200"
    p "error_at #{i}"
    p result.code
    p result.body
    exit
  end
}

puts secs

sum = secs.inject(0,&:+)
avg = sum / 10
var = secs.map { |i| (i - avg) ** 2 }.inject(0,&:+) / 9
stddev = Math.sqrt(var)

puts "average: #{avg}"
puts "standard deviation: #{stddev}"