passenger_rails_processes_memory.rb

#!/usr/bin/env ruby                                                                                                           

def output_config
  puts <<-END
graph_category passenger                                                                                                      
graph_title rails processes memory                                                                                            
graph_vlabel megabytes                                                                                                        
graph_info This graph shows the average, min and max memory consumption made by rails processes.                              
graph_order max average min                                                                                                   
max.label max                                                                                                                 
max.draw AREA                                                                                                                 
max.info Top memory consomption by a rails process.                                                                           
min.label min                                                                                                                 
min.draw AREA                                                                                                                 
min.info Memory used by the application min (minimum memory consumption).                                                     
average.label average                                                                                                         
average.draw AREA                                                                                                             
average.info average memory consummed by all rails processes.                                                                 
END
  exit 0
end

def output_values
  stats = `sudo passenger-memory-stats`
  unless $?.success?
    $stderr.puts "failed executing passenger-memory-stats"
    exit 1
  end

  rails_processes = stats.scan(/\d+\s+\d+.\d+ MB\s+(\d+.\d+) MB\s+Rails/).flatten.collect(&:to_f)
  puts "max.value #{rails_processes.max}"
  puts "average.value #{rails_processes.inject(:+) / rails_processes.length.to_f}"
  puts "min.value #{rails_processes.min}"
end

if ARGV[0] == "config"
  output_config
else
  output_values
end