Resque Alarm

Send out an alarm (at this time, just support email, logger) when queue length reach a threshold.

To use this gem, config in an initializer

  require 'resque/plugins/alarm'
  require 'resque/plugins/alarm_notifier/log_notifier'
  # OR
  require 'resque/plugins/alarm_notifier/mail_notifier'

  Resque::Plugins::Alarm.configure do |config|
    config.threshold = 10 # Perform notify when queue have more than 10 items
    config.notifier = Resque::Plugins::AlarmNotifier::LogNotifier.new(Rails.logger, :info, "MyFantasticApp") # Notify to rails log
    # OR using mail notifier
    config.notifier = Resque::Plugins::AlarmNotifier::MailNotifier.new(
      "from@from.com",
      "to@to.com",
      "Queue length reached alarm", # subject
      ["Resque"] ) # tags, merge with subject to become "[Resque] Queue length reached alarm"
  end

Extend in job:

  require 'resque/plugins/alarm'

  class ResqueDoSomethingJob
    extend Resque::Plugins::Alarm

    @queue = :line1

    def self.perform(params)
      # magic come here
    end

  end

While enqueueing, if any queue has more than 10 items, a log as below will be written to rails log

  {:app=>"MyFantasticApp", :source=>"resque-queue-length-alarm", :type=>"resque_queue_too_long", :queues=>{:artwork_file_serve=>11}}

Email may be very noisy, it's better to use rails log and let log system decide email threshold.

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