Delayed extensions provide a very easy and simple way to make method calls asynchronous. By default, all class methods and ActionMailer deliveries can be performed asynchronously.
They are disabled by default in Sidekiq 5+. Use
Sidekiq::Extensions.enable_delay! to turn them on.
delay to deliver your emails asynchronously. Use
delay_until(time) to deliver the email at some point in the future.
UserMailer.delay.welcome_email(@user.id) UserMailer.delay_for(5.days).find_more_friends_email(@user.id) UserMailer.delay_until(5.days.from_now).find_more_friends_email(@user.id)
It is recommended to avoid passing an object instance to mailer methods. Instead, pass an object id and then re-instantiate the object in the mailer method, per Best Practices.
delay_until(time) to asynchronously execute arbitrary methods on your ActiveRecord classes.
User.delay.delete_old_users('some', 'params') User.delay_for(2.weeks).whatever User.delay_until(2.weeks.from_now).whatever
I strongly recommend avoiding delaying methods on instances. This stores object state in Redis which can get out of date, causing stale data problems.
Any class method can be delayed via the same methods as above:
MyClass.delay.some_method(1, 'bob', true)
Remember to keep method arguments simple, don't pass complex Ruby objects.
You can tune the options used with a
.delay call by passing in options:
MyClass.delay(retry: false).some_method(1, 2, 3) MyClass.delay(queue: 'low').some_method(1, 2, 3) MyClass.delay_for(10.minutes, retry: false).some_method(1, 2, 3)
The extensions have two drawbacks:
- they use YAML to serialize arguments so the job payload can become very large easily if passing complex Ruby objects.
- they add methods to
For these reasons, they are disabled by default.