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Uncategorized delayed_job rails3
setting up delayed_job in rails3

If you want to run longrunning jobs in the background, one very easy solution is using delayed_job. One other very interesting alternative is resque, but it seemed harder to setup (it uses redis), and delayed_job seemed to be just right for my needs. In short (from the redis documentation) : Choose Resque if:

  • You need multiple queues
  • You don't care / dislike numeric priorities
  • You don't need to persist every Ruby object ever
  • You have potentially huge queues
  • You want to see what's going on
  • You expect a lot of failure / chaos
  • You can setup Redis
  • You're not running short on RAM Choose DelayedJob if:
  • You like numeric priorities
  • You're not doing a gigantic amount of jobs each day
  • Your queue stays small and nimble
  • There is not a lot failure / chaos
  • You want to easily throw anything on the queue
  • You don't want to setup Redis And in my case: a short list of outstanding jobs, i am using a database already, not sure about redis, performance is not that important, i do not expect a lot of failure, i do not want to setup redis (yet :). So to use the delayed_job gem in a rails3 you will need to use the code from github (as the gem version 2.0.3 is not yet rails3 compatible). Add the following line to your Gemfile : [ruby] gem "delayed_job", :git => 'git://' [/ruby] and then run [bash] bundle install [/bash] Because i am using ActiveRecord, i can just use the generator, that will create the table and add the script to run a worker: [ruby] rails generate delayed_job rake db:migrate [/ruby] Include the rake tasks from delayed-jobs into your Rakefile: [ruby] begin require 'delayed/tasks' rescue LoadError STDERR.puts "Run bundle:install to install delayed_job" end [/ruby] Create an initializer file delayed_jobs_config.rb and write [ruby] # config/initializers/delayed_job_config.rb Delayed::Worker.destroy_failed_jobs = false #Delayed::Worker.sleep_delay = 60 #Delayed::Worker.max_attempts = 3 Delayed::Worker.max_run_time = 5.minutes [/ruby] If you are happy with the defaults, you can leave it. For me it was important to keep a record of the jobs that failed. Then you can just delay any function-call like this: [ruby] envelope.delay.query_status(delivery) [/ruby] Just adding the .delay does all the magic for you! And starting a worker is as simple as [ruby] rake jobs:work [/ruby]
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