"Maybe we should have a talk on delayed_job"@subelsky

An Introduction to delayed_job

@bmoreonrails2009-11-10

I’m @jonathanjulian

Why do we need background processing?

User Experience

Sending an email

Resizing an image

Updating a web service

Geocoding

Batch import

Delayed::Job

“Extracted from Shopify”

database-persisted queue

0..n runners

tobi/delayed_job

collectiveidea/delayed_job

Setup

gem

The Queue

One db migration

Let’s delay something

Notifier.deliver_activation_instructions(self)

Notifier.send_later(:deliver_activation_instructions,

self)

Easy!

class Notifier def deliver_activation_instructions(user) # ... end handle_asynchronously :deliver_activation_instructionsend

Custom jobs

class LongRunningJob < Struct.new(:id) def perform # do some crazy long calculations endend

Delayed::Job.enqueue LongRunningJob.new(42)

Who runs the jobs?

Workers

rake jobs:work # Start a delayed_job worker.

script/delayed_job start

* collectiveidea/delayed_job only

Production Deployment

# play nice with Passengerrequire 'delayed/recipes'after "deploy:update_code", "delayed_job:stop"after "deploy:restart", "delayed_job:start"

http://railstips.org/2008/11/19/delayed-

gratification-with-rails

"I highly recommend DelayedJob to anyone whose site is not 50%

background work." @defunkt

@jonathanjulianhttp://jonathanjulian.com/

Photo Attributions

• http://www.flickr.com/photos/aloshbennett/540105576/

• http://www.flickr.com/photos/gyrus/132436475/

• http://www.flickr.com/photos/gavatron/866650954/