gistfile1.rb

#!/usr/bin/env ruby
#
# Find bloating passengers and kill them gracefully. Run from cron every minute.
#

# required for passenger since cron has no environment
ENV['HTTPD'] = 'httpd'

MEM_LIMIT = ARGV[0] || 500

module Process
  def self.running?(pid)
    begin
      return Process.getpgid(pid) != -1
    rescue Errno::ESRCH
      return false
    end
  end
end

`passenger-memory-stats`.each_line do |line|
  if line =~ /Rails: /
    parts = line.split
    pid, private_dirty_rss = parts[0].to_i, parts[4].to_f
    
    if private_dirty_rss > MEM_LIMIT.to_i
      puts "Found bloater #{pid} with size #{private_dirty_rss.to_s}"
      puts "Killing with SIGUSR1 (graceful)..."
      Process.kill("SIGUSR1", pid)
      puts "Finished kill attempt. Sleeping for 8 seconds..."
      sleep 8
      if Process.running?(pid)
        puts "Process is still running, so killing with extreme predjudice!"
        Process.kill("TERM", pid)
      end
      puts "Done!"
    end

  end
end

all of them suffer from one issue, if meanwhile new process with that ID is spawned, it will get killed.

ENV['HTTPD'] = 'httpd' < Why set that on ENV if you just overwrite it even if they set it? 😉