Class: WebBenchmark

Inherits:
Object
  • Object
show all
Defined in:
lib/web_benchmark.rb,
lib/results.rb,
lib/fetcher.rb,
lib/interpretor.rb

Overview

Perform a visitors benchmark on a web resource (be it app or site)

Drill down

  • Start X threads

  • Let each thread perform an average of Y requests (count -/+ rand(count))

  • Make sure the user waits < Z seconds before requesting the next page

This way you can mimic a number of visitors on your site and see what that does for

  • The load on your webserver (keep an eye on that!)

  • The speed per request

Assets

By default each visitor will request the assets (img, script, css) it encounters (unless seen before). The time it takes to load these assets is added to the request time

Defined Under Namespace

Classes: Fetcher, Interpretor, Results

Constant Summary

VERSION =
'1.0.0'

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(start_point, count = 5, visitors = 2, sleep = 500) ⇒ WebBenchmark

Returns a new instance of WebBenchmark



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# File 'lib/web_benchmark.rb', line 27

def initialize(start_point, count=5, visitors=2, sleep=500)
  @start_point = start_point
  @visitors    = visitors
  @count       = count

  sleep *= 100 if sleep < 100
  @sleep = sleep

  @noisy          = false
  @include_assets = true
end

Instance Attribute Details

#countObject

Returns the value of attribute count



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# File 'lib/web_benchmark.rb', line 25

def count
  @count
end

#include_assetsObject

Returns the value of attribute include_assets



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# File 'lib/web_benchmark.rb', line 25

def include_assets
  @include_assets
end

#noisyObject

Returns the value of attribute noisy



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# File 'lib/web_benchmark.rb', line 25

def noisy
  @noisy
end

#start_pointObject

Returns the value of attribute start_point



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# File 'lib/web_benchmark.rb', line 25

def start_point
  @start_point
end

#visitorsObject

Returns the value of attribute visitors



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# File 'lib/web_benchmark.rb', line 25

def visitors
  @visitors
end

Instance Method Details

#benchmark(url) ⇒ Object

how well does the resource perform.

The total time of the request is stored in WebBenchmark::Results

before the benchmark is started, a sleep time is introduced. This helps to spread out (and randomize) the #visitors

The requested page is analyzed and a next link is choosen if the visitor still has pages left to visit



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# File 'lib/web_benchmark.rb', line 122

def benchmark(url)
  me = Thread.current

  if @sleep != 0
    slumber = ((rand(@sleep)+1)/100.0)
    shout "#{me[:name]}: sleep #{slumber}"

    Kernel::sleep(slumber)
  end

  shout "#{me[:name]}: #{url}"

  fetcher = Fetcher.new(url)
  res = fetcher.fetch

  if res == false
    shout "#{me[:name]}: error on #{url}"
    return
  end

  if @include_assets == true and !fetcher.body.nil?
    fetched = fetcher.fetch_assets(me[:assets_cache])
    shout("Fetched assets: #{fetched.join(", ")}")
    me[:assets_cache] += fetched
  end

  r = Results.instance(url)
  r.record(fetcher.start, fetcher.stop, fetcher.result.status)

  links = []
  if fetcher.body
    fetcher.body.css('a').each do |a|
      link = a[:href]
      if link =~ /^\//
        link = @start_point + link

      elsif link !~ /https?:/
        begin
          base = url.gsub(/[^\/]+$/, '')
          link = base + link
        rescue
        end
      end

      links << link unless link !~ Regexp.new(@start_point)
    end
  end

  if me[:count] > 1
    me[:count] -= 1

    next_url = nil
    tries    = 0
    while next_url.nil? and tries < 10
      next_url = links[rand(links.length-1)]
      begin
        URI.parse(next_url)
      rescue
        next_url = nil
      end
      tries += 1
    end

    if next_url.nil?
      shout("Cannot find another link on #{url} #{fetcher.result.status}- restarting on start point")
      return benchmark(@start_point)
    end

    benchmark(next_url.gsub(/([^:])\/\//, '\1/'))
  end
end

#full_test(cool_down = 5) ⇒ Object

Perform a full test - this will show you how things 'scale'

First, a base line is established by performing #count visits with only one #visitors. This would generate a sample that should serve as the 'nominal' operation of the resource

Then we let things cool down for some seconds and perform a test with only half the number of visitors requested

Cool down again and finaly go in full blast.

You will be handed an interpretor holding 3 result sets to play with



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# File 'lib/web_benchmark.rb', line 52

def full_test(cool_down=5)
  puts "Perfoming a full test"
  interpretor = Interpretor.new(false)

  visitors_before  = self.visitors

  # first, establish a base line 1 client - 20 requests
  self.visitors = 1
  self.start

  interpretor.sets << Results.get_all
  Results.clear

  puts "Letting the server cool down #{cool_down}s"
  sleep cool_down

  self.visitors = visitors_before / 2
  self.start

  interpretor.sets << Results.get_all
  Results.clear

  puts "Letting the server cool down #{cool_down}s"
  sleep cool_down

  self.visitors = visitors_before
  self.start

  interpretor.sets << Results.get_all

  return interpretor
end

#shout(msg) ⇒ Object



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# File 'lib/web_benchmark.rb', line 195

def shout msg
  return if !@noisy
  $stderr.puts msg
end

#startObject

start all #visitors



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# File 'lib/web_benchmark.rb', line 87

def start
  threads = []

  start = Time.now

  puts "Starting benchmark with #{@visitors} visitors for #{@count} pages..."
  @visitors.times { |i|
    threads << Thread.new(@start_point, @count) do |url, count|
      Thread.current[:count]        = (
        rand(2) == 1 ? count - rand(count) : count + rand(count)
      )
      Thread.current[:name]         = "[Visitor-#{i+1}]"
      Thread.current[:assets_cache] = []

      benchmark(url)
    end
  }

  shout "Waiting for #{threads.count} threads"
  threads.collect(&:join)

  puts "Benchmark took: #{"%.2f" % (Time.now - start)}"
  return
end