Beanstalkd is a fast, lightweight queueing backend inspired by mmemcached. The Ruby Beanstalk client is a bit raw, however, so Stalker provides a thin wrapper to make job queueing from your Ruby app easy and fun.
From anywhere in your app:
require 'stalker'
Stalker.enqueue('email.send', :to => '[email protected]')
Stalker.enqueue('post.cleanup.all')
Stalker.enqueue('post.cleanup', :id => post.id)
In a standalone file, typically jobs.rb or worker.rb:
require 'stalker'
include Stalker
job 'email.send' do |args|
Pony.send(:to => args['to'], :subject => "Hello there")
end
job 'post.cleanup.all' do |args|
Post.all.each do |post|
enqueue('post.cleanup', :id => post.all)
end
end
job 'post.cleanup' do |args|
Post.find(args['id']).cleanup
end
First, make sure you have Beanstalkd installed and running:
$ sudo port install beanstalkd
$ beanstalkd
Stalker:
$ sudo gem install stalker
Now run a worker using the stalk binary:
$ stalk jobs.rb
Working 3 jobs: [ email.send post.cleanup.all post.cleanup ]
Working send.email ([email protected])
Finished send.email in 31ms
Stalker will log to stdout as it starts working each job, and then again when the job finishes including the ellapsed time in milliseconds.
Filter to a list of jobs you wish to run with an argument:
$ stalk jobs.rb post.cleanup.all,post.cleanup
Working 2 jobs: [ post.cleanup.all post.cleanup ]
In a production environment you may run one or more high-priority workers (limited to short/urgent jobs) and any number of regular workers (working all jobs). For example, two workers working just the email.send job, and four running all jobs:
$ for i in 1 2; do stalk jobs.rb email.send > log/urgent-worker.log 2>&1; end
$ for i in 1 2 3 4; do stalk jobs.rb > log/worker.log 2>&1; end
If you include an error block in your jobs definition, that block will be invoked when a worker encounters an error. You might use this to report errors to an external monitoring service:
error do |e, job, args|
Exceptional.handle(e)
end
If you wish to run a block of code prior to any job:
before do |job|
puts "About to work #{job}"
end
- Jobs are serialized as JSON, so you should stick to strings, integers, arrays, and hashes as arguments to jobs. e.g. don't pass full Ruby objects - use something like an ActiveRecord/MongoMapper/CouchRest id instead.
- Because there are no class definitions associated with jobs, you can queue jobs from anywhere without needing to include your full app's environment.
- If you need to change the location of your Beanstalk from the default (localhost:11300), set BEANSTALK_URL in your environment, e.g. export BEANSTALK_URL=beanstalk://example.com:11300/. You can specify multiple beanstalk servers, separated by whitespace or comma, e.g. export BEANSTALK_URL="beanstalk://b1.example.com:11300/, beanstalk://b2.example.com:11300/"
- The stalk binary is just for convenience, you can also run a worker with a straight Ruby command: $ ruby -r jobs -e Stalker.work
If you wish to hack on Stalker, install these extra gems:
$ gem install contest mocha
Make sure you have a beanstalkd running, then run the tests:
$ ruby test/stalker_test.rb
Created by Adam Wiggins
Patches from Jamie Cobbett, Scott Water, Keith Rarick, Mark McGranaghan, Sean Walberg, Adam Pohorecki, Han Kessels
Heavily inspired by Minion by Orion Henry
Released under the MIT License: http://www.opensource.org/licenses/mit-license.php