How to restart Resque workers automatically when Redis server restarts - ruby-on-rails

Question

I have a Rails application that runs jobs on the background using the Resque adapter. I have noticed that once a couple of days my workers disappear (just stop), my jobs get stuck in the queue, and I have to restart the workers anew every time they stop.
I check using ps -e -o pid,command | grep [r]esque and launch workers in the background using
(RAILS_ENV=production PIDFILE=./resque.pid BACKGROUND=yes bundle exec rake resque:workers QUEUE='*' COUNT='12') 2>&1 | tee -a log/resque.log.
Then I stopped redis-server using /etc/init.d/redis-server stop and again checked the worker processes. They disappeared.
This gives a reason to think that worker processes stop maybe because the redis server restarting because of some reason.
Is there any Rails/Ruby way solution to this problem? What comes to my mind is writing a simple Ruby code that would watch the worker processes with the period, say, 5 seconds, and restart them if they stop.
UPDATE:
I don't want to use tools such as Monit, God, eye, and etc. They are not reliable. Then I will need to watch them too. Something like to install God to manage Resque workers, then install Monit to watch God, ...
UPDTAE
This is what I am using and it is really working. I manually stoped redis-server and then started it again. This script successfully launched the workers.
require 'logger'
module Watch
def self.workers_dead?
processes = `ps -e -o pid,command | grep [r]esque`
return true if processes.empty?
false
end
def self.check(time_interval)
logger = Logger.new('watch.log', 'daily')
logger.info("Starting watch")
while(true) do
if workers_dead?
logger.warn("Workers are dead")
restart_workers(logger)
end
sleep(time_interval)
end
end
def self.restart_workers(logger)
logger.info("Restarting workers...")
`cd /var/www/agts-api && (RAILS_ENV=production PIDFILE=./resque.pid BACKGROUND=yes rake resque:workers QUEUE='*' COUNT='12') 2>&1 | tee -a log/resque.log`
end
end
Process.daemon(true,true)
pid_file = File.dirname(__FILE__) + "#{__FILE__}.pid"
File.open(pid_file, 'w') { |f| f.write Process.pid }
Watch.check 10

Answer 1

You can use process monitoring tools such as monit, god, eye etc. These tools can check for resque PID and memory usage at time interval specified by you. You also have options to restart background processes if the memory limit exceeds your specified expectations. Personally, I use eye gem.

Answer 2

You could do it much simpler. Start Resque in foreground. When it exits, start it again. No pid files, no monitoring, no sleep.
require 'logger'
class Restarter
def initialize(cmd:, logger: Logger.new(STDOUT))
#cmd = cmd
#logger = logger
end
def start
loop do
#logger.info("Starting #{#cmd}")
system(#cmd)
#logger.warn("Process exited: #{#cmd}")
end
end
end
restarter = Restarter.new(
cmd: 'cd /var/www/agts-api && (RAILS_ENV=production rake resque:workers QUEUE='*' COUNT='12') 2>&1 | tee -a log/resque.log',
logger: Logger.new('watch.log', 'daily')
)
restarter.start