_scheduler.rb

  class Scheduler < Rufus::Scheduler::PlainScheduler
    def initialize(zk, *args)
      super(*args)

      @zk_locker = zk.exclusive_locker('scheduler')
    end

    def run
      @zk_locker.with_lock do
        configure
        start
        join
      end
    end

    def configure
      every '1h' do
        Resque.enqueue(Jobs::Hourly)
      end

      every '1m' do
        Resque.enqueue(Jobs::Minute)
      end

      # ...
    end

    protected
    def log_exception(e)
      case e
      when Interrupt, SignalException, SystemExit
        # nothing
        raise
      else
        ExceptionNotifier.notify(e)
      end
    end

    # If we want to do something before
    def before_job(job)
      begin
        @zk_locker.assert!
      rescue ZK::Exceptions::LockAssertionFailedError => e
        ExceptionNotifier.notify(e)

        # Tell the world to stop
        stop
      end

      # Verify ActiveRecord connections
      ActiveRecord::Base.connection_handler.verify_active_connections!
    end

    def after_job(job)
      # Let go of the ActiveRecord connection
      ActiveRecord::Base.clear_active_connections!
    end
  end

hooks_for_rufus_scheduler.rb

require 'rufus/scheduler'

class Rufus::Scheduler::Job
  def trigger_block_with_hooks
    trigger_scheduler_hook(:before_job)

    trigger_block_without_hooks
  ensure
    trigger_scheduler_hook(:after_job)
  end
  alias_method_chain :trigger_block, :hooks

  def trigger_scheduler_hook(method)
    if @scheduler.respond_to?(method)
      @scheduler.method(method).arity == 1 ? @scheduler.send(method, self) : @scheduler.send(method)
    end
  end
end