Inspecting Phusion Passenger's status and killing frozen apps

kill-frozen-passenger-instances

#!/usr/bin/ruby -w

# for passenger 3.0
#
# cron
# */15 * * * *     root /root/bin/kill-frozen-passenger-instances

require 'rubygems'
require 'net/http'
require 'uri'
require 'xml'

def main
  parse_status(`passenger-status --show=xml`).each do |instance|
    if pid = test_instance(instance, '/')
      kill_process(pid)
    end
  end
end

def parse_status(xml)
  XML::Document.string(xml).find('//process').map do |process|
    data = Proc.new { |xpath| 
      process.find_first(xpath).content rescue nil
    }

    if (pid      = data['pid']) && 
       (password = data['connect_password']) && 
       (address  = data['server_sockets/server_socket[name = "http"]/address'])
      { :pid => pid.to_i, :password => password, :address => address }
    end
  end.compact
end

def test_instance(instance, path = '/')
  url = URI.parse('http://' + instance[:address])

  Net::HTTP.start(url.host, url.port) do |http|
    req = Net::HTTP::Get.new(path)
    req.add_field('X-Passenger-Connect-Password', instance[:password])

    http.open_timeout = 2
    http.read_timeout = 2
    http.request(req)
  end

  nil
rescue Timeout::Error
  instance[:pid]
rescue => e
  puts "#{e.class}: #{e.message}"
  nil
end

def kill_process(pid)
  begin
    10.times do
      Process.kill('ABRT', pid)
      sleep 0.2
    end
  rescue Errno::ESRCH
    puts "Process with PID #{pid} killed"
  end
end

main()

Nice! Any reason for 10.times kill instead of loop? ;-)
Also:
def parse_status(xml)
XML::Document.string(xml).find('//process').map do |process|
data = Proc.new { |xpath| process.find_first(xpath).content rescue nil }

    if (pid      = data['pid']) && 
       (password = data['connect_password']) && 
       (address  = data['server_sockets/server_socket[name = "http"]/address'])
      { :pid => pid.to_i, :password => password, :address => address }
    end
  end.compact
end

Thanks.

Any reason for 10.times kill instead of loop? ;-)

I'm not sure about zombie processes, so make a finite loop.

Понятно :-) Зомбей по идее убивает Process.kill('KILL', pid) или sudo kill -9 #{pid}

Не, зомби по определению уже не живой, поэтому убивать нечего ;) Можно убить родителя, но в данном случае как-то не хочется )