Class: StepperMotor::ForwardScheduler

Inherits:
Object
  • Object
show all
Defined in:
lib/stepper_motor/forward_scheduler.rb

Overview

The forward scheduler enqueues a job for every Journey that gets sent to the #schedule. The job is then stored in the queue and gets picked up by the ActiveJob worker normally. This is the simplest option if your ActiveJob adapter supports far-ahead scheduling. Some adapters, such as SQS, have limitations regarding the maximum delay after which a message will become visible. For SQS, the limit is 900 seconds. If the job is further in the future, it is likely going to fail to get enqueued. If you are working with a queue adapter that:

  • Does not allow easy introspection of jobs in the future (like Redis-based queues)
  • Limits the value of the wait: parameter

this scheduler may not be a good fit for you, and you will need to use the CyclicScheduler instead. Note that this scheduler is also likely to populate your queue with a high number of "far out" jobs to be performed in the future. Different ActiveJob adapters are known to have varying performance depending on the number of jobs in the queue. For example, good_job is known to struggle a bit if the queue contains a large number of jobs (even if those jobs are not yet scheduled to be performed). For good_job the CyclicScheduler is also likely to be a better option.

Direct Known Subclasses

CyclicScheduler

Instance Method Summary collapse

Instance Method Details

#schedule(journey) ⇒ Object 



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# File 'lib/stepper_motor/forward_scheduler.rb', line 21

def schedule(journey)
  StepperMotor::PerformStepJob
    .set(wait_until: journey.next_step_to_be_performed_at)
    .perform_later(journey_id: journey.id, journey_class_name: journey.class.to_s, idempotency_key: journey.idempotency_key)
end