Monitor your Phusion passenger instances. This script allows you to automatically gracefully reload passenger instances (if they ate too much memory). See the required library: https://gist.github.com/serg-kovalev/71af1ccd121fba7ef56e

script_passenger_monitor.rb

#!/usr/bin/env ruby
require File.expand_path(File.join(File.dirname(__FILE__), '..', 'lib', 'passenger_monitor'))
# Set logger to log into Rails project /log directory and start monitoring
PassengerMonitor.run(
    :log_file => File.join(File.dirname(__FILE__), '..', 'log', 'passenger_monitor.log'),
    :memory_limit => 400, # this is in MB
    :wait_time => 10, # this in seconds (timeout before attempts)
    :attempts => 5 # number of attempts
)