cpu use test script

gistfile1.rb

#!/usr/bin/env ruby

# we're seeing some odd slowdown on hosts. It kind of looks like the
# host is pausing for some number of milliseconds, which hits the
# various ruby processes. It would be nice if we understood what was
# happening. This is a small script to help understand it.

# theory:
# Do work that takes about N
# Measure elapsed time M
# whine if they differ my more than X


class Integer
  def factors() (1..self).select { |n| (self % n).zero? } end
end


program_start = Time.now.to_f

while true
  runtime = Time.now.to_f - program_start
  #puts "Total runtime: #{runtime}"

  start = Time.new.to_f

  # Do some work. Looking for factors is work.
  # this set of math was arrived at somewhat experimentally.
  (100000 + rand(99999)).factors
  (100000 + rand(99999)).factors

  elapsed = Time.new.to_f - start

  puts elapsed

  whine_time = 0.500
  
  if elapsed > whine_time
    puts "uh oh"
    puts "This round took took #{elapsed}"
    exit
  end
end