resque-metrics¶ ↑

A simple Resque plugin that times and saves some simple metrics for Resque jobs back into redis. Based on this system you could build some simple auto-scaling mechanism based on the speed and ETA of queues. Also includes a hook/callback mechanism for recording/sending the metrics to your favorite tool (AKA statsd/graphite).

Installation¶ ↑

gem install resque-metrics

Usage¶ ↑

Given a job, extend the job class with Resque::Metrics.

class SomeJob
  extend ::Resque::Metrics

  @queue = :jobs

  def self.perform(x, y)
    # sleep 10
  end

end

By default this will record the total job count, the total count of jobs enqueued, the total time the jobs took, the avg time the jobs took. It will also record each of these per-queue and per-bob class. So for the job above it will record values and you will be able to fetch them with module methods:

Resque::Metrics.total_job_count #=> 1
Resque::Metrics.total_job_count_by_job(SomeJob) #=> 1
Resque::Metrics.total_job_count_by_queue(:jobs) #=> 10000
Resque::Metrics.total_job_time #=> 10000
Resque::Metrics.total_job_time_by_job(SomeJob) #=> 10000
Resque::Metrics.total_job_time_by_queue(:jobs) #=> 10000
Resque::Metrics.avg_job_time #=> 1000
Resque::Metrics.avg_job_time_by_job(SomeJob) #=> 1000
Resque::Metrics.avg_job_time_by_queue(:jobs) #=> 1000

All values are recorded and returned as integers. For times, values are in milliseconds.

Forking Metrics¶ ↑

Resque::Metrics can also record forking metrics but these are not on by default as ‘before_fork` and `after_fork` are singluar hooks. If you don’t need to define your own fork hooks you can simply add a line to an initializer:

Resque::Metrics.watch_fork

If you do define you’re own fork hooks:

Resque.before_fork do |job|
  # my own fork code
  Resque::Metrics.before_fork.call(job)
end

# Resque::Metrics.(before/after)_fork just returns a lambda so just assign it if you like
Resque.after_fork = Resque::Metrics.after_fork

Once enabled this will add ‘.fork` methods like `avg_fork_time`, etc. Latest Resque is required for fork recording to work.

Callbacks/Hooks¶ ↑

Resque::Metrics also has a simple callback/hook system so you can send data to your favorite agent. All hooks are passed the job class, the queue, and the time of the metric.

# Also `on_job_fork` and `on_job_enqueue`
Resque::Metric.on_job_complete do |job_class, queue, time|
  # send to your metrics agent
  Statsd.timing "resque.#{job_class}.complete_time", time
  Statsd.increment "resque.#{job_class}.complete"
  # etc
end

Contributing to resque-metrics¶ ↑

• Check out the latest master to make sure the feature hasn’t been implemented or the bug hasn’t been fixed yet

• Check out the issue tracker to make sure someone already hasn’t requested it and/or contributed it

• Fork the project

• Start a feature/bugfix branch

• Commit and push until you are happy with your contribution

• Make sure to add tests for it. This is important so I don’t break it in a future version unintentionally.

• Please try not to mess with the Rakefile, version, or history. If you want to have your own version, or is otherwise necessary, that is fine, but please isolate to its own commit so I can cherry-pick around it.

Copyright¶ ↑

Copyright © 2011 Aaron Quint. See LICENSE.txt for further details.