Action Profiler allows you to profile a single Rails action to determine what to optimize. You can use the Production Log Analyzer and action_grep to determine which actions you should profile and what arguments to use.
Information on the Production Log Analyzer can be found at:
rails-analyzer.rubyforge.org/pl_analyze
Action Profiler REQUIRES Ruby 1.8.3, even if you just use Ruby’s builtin profiler.
Action Profiler can use three profilers, Ruby’s builtin profiler class, Shugo Maeda’s Prof or Ryan Davis’ ZenProfile.
Shugo Maeda’s Prof: raa.ruby-lang.org/project/ruby-prof
Ryan Davis’ ZenProfile: rubyforge.org/frs/?group_id=712&release_id=2476
Gem Installation
gem install action_profiler