How to profile your Rails and Ruby applications with ruby-prof

2 h2. Installing ruby-prof First install "ruby-prof":http://ruby-prof.rubyforge.org/: <code> git clone git://github.com/jeremy/ruby-prof.git cd ruby-prof/ rake gem sudo gem install pkg/ruby-prof-0.6.1.gem </code> Note that version 0.6.0 doesn't work, at least not with Rails 2.1.1. With 0.6.0 I got this message: <code> `gem install ruby-prof` to use the profiler </code> h2. Setting up a new environment for profiling Create *config/environments/profiling.rb*: <code> config.cache_classes = true config.action_controller.consider_all_requests_local = false config.action_controller.perform_caching = true config.action_view.cache_template_loading = true #config.log_level = :debug </code> Add the new environment to database.yml. You might want to reuse the development database. h2. Creating a profiling script Next we'll create a script that simply fetches the homepage, save the following code in *profiling/homepage.rb*: <code> get '/' say "GET / => #{path}" </code> h2. Run the script Now run the script 100 times: <code> RAILS_ENV=profiling ./script/performance/request -n 100 profiling/homepage.rb </code> h2. Profiling plain Ruby applications You can also profile a block of code by "calling RubyProf from your code":http://ruby-prof.rubyforge.org/: <code> require 'ruby-prof' # Profile the code RubyProf.start ... [code to profile] ... results = RubyProf.stop File.open "#{RAILS_ROOT}/tmp/profile-graph.html", 'w' do |file| RubyProf::GraphHtmlPrinter.new(results).print(file) end File.open "#{RAILS_ROOT}/tmp/profile-flat.txt", 'w' do |file| RubyProf::FlatPrinter.new(results).print(file) end File.open "#{RAILS_ROOT}/tmp/profile-tree.prof", 'w' do |file| RubyProf::CallTreePrinter.new(results).print(file) end </code> h2. Analyzing results I prefer to use the RubyProf::CallTreePrinter to output data that "kcachegrind":http://kcachegrind.sourceforge.net/ can read. The HTML and text data is difficult to read so kcachegrind will definitely make your life easier. On OSX you can install kcachegrind with "Fink":http://www.finkproject.org/download/index.php?phpLang=en (or DarwinPorts): <code> sudo apt-get update ; sudo apt-get install fink sudo apt-get install kcachegrind </code> There's also WinCacheGrind and MacCacheGrind, but I haven't tried those. 0

2008-09-26T22:25:54+03:00

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<h2>Installing ruby-prof</h2> First install <a href="http://ruby-prof.rubyforge.org/">ruby-prof</a>: <pre class="active4d"> 1 git clone git://github.com/jeremy/ruby-prof.git 2 cd ruby-prof/ 3 rake gem 4 sudo gem install pkg/ruby-prof-0.6.1.gem </pre> Note that version 0.6.0 doesn’t work, at least not with Rails 2.1.1. With 0.6.0 I got this message: <pre class="active4d"> 1 `gem install ruby-prof` to use the profiler </pre> <h2>Setting up a new environment for profiling</h2> Create config/environments/profiling.rb: <pre class="active4d"> 1 config.cache_classes = true 2 config.action_controller.consider_all_requests_local = false 3 config.action_controller.perform_caching = true 4 config.action_view.cache_template_loading = true 5 6 #config.log_level = :debug </pre> Add the new environment to database.yml. You might want to reuse the development database. <h2>Creating a profiling script</h2> Next we’ll create a script that simply fetches the homepage, save the following code in profiling/homepage.rb: <pre class="active4d"> 1 get '/' 2 say "GET / => #{path}" </pre> <h2>Run the script</h2> Now run the script 100 times: <pre class="active4d"> 1 RAILS_ENV=profiling ./script/performance/request -n 100 profiling/homepage.rb </pre> <h2>Profiling plain Ruby applications</h2> You can also profile a block of code by <a href="http://ruby-prof.rubyforge.org/">calling RubyProf from your code</a>: <pre class="active4d"> 1 require 'ruby-prof' 2 3 # Profile the code 4 RubyProf.start 5 ... 6 [code to profile] 7 ... 8 results = RubyProf.stop 9 10 File.open "#{RAILS_ROOT}/tmp/profile-graph.html", 'w' do |file| 11 RubyProf::GraphHtmlPrinter.new(results).print(file) 12 end 13 14 File.open "#{RAILS_ROOT}/tmp/profile-flat.txt", 'w' do |file| 15 RubyProf::FlatPrinter.new(results).print(file) 16 end 17 18 File.open "#{RAILS_ROOT}/tmp/profile-tree.prof", 'w' do |file| 19 RubyProf::CallTreePrinter.new(results).print(file) 20 end </pre> <h2>Analyzing results</h2> I prefer to use the RubyProf::CallTreePrinter to output data that <a href="http://kcachegrind.sourceforge.net/">kcachegrind</a> can read. The HTML and text data is difficult to read so kcachegrind will definitely make your life easier. On OSX you can install kcachegrind with <a href="http://www.finkproject.org/download/index.php?phpLang=en">Fink</a> (or DarwinPorts): <pre class="active4d"> 1 sudo apt-get update ; sudo apt-get install fink 2 sudo apt-get install kcachegrind </pre> There’s also WinCacheGrind and MacCacheGrind, but I haven’t tried those.

How to profile your Rails and Ruby applications with ruby-prof

2008-12-13T12:52:21+02:00