Delayed Job Queue, Priority, Worker

Question

I have around 10 queues in my code, each having separate workers. All have default priorities - 1.

Currently, the requests coming from user (UI) & rake tasks are going in same queue. Suppose, request coming for fetching data from user & rake task are going in same queue with priority 1 & both are executing one by one depends on request time.

But I want to run the request from user first & then the rake task. How can I manage this ?

I also want to understand if I create a separate queue for rake task & give it low priority, then how it will work. Will it run along with another queues or wait for them to execute first?

Delayed::Worker.queue_attributes = {
  high_priority: { priority: -10 },
  low_priority: { priority: 10 }
}

Answer 1

But I want to run the request from user first & then the rake task. How can I manage this ?

Recommend change Delayed::Worker.default_priority to a positive number, for example: 5, then define a priority method in the user workers return a lower number

class UserRequestJob < ApplicationJob
  def priority
    1 # lower numbers run first
  end
  ...
end

I also want to understand if I create a separate queue for rake task & give it low priority, then how it will work. Will it run along with another queues or wait for them to execute first?

It will run higher priority jobs first, and then lower priority jobs, in fact queue name doesn't matter after a job is enqueued, unless you have dedicated workers, when you define queues with priority:

Delayed::Worker.queue_attributes = {
  high_priority: { priority: -10 },
  low_priority: { priority: 10 }
}

and then you enqueue a job to a queue, delayed_job will get the priority by queue name, as you can see in job_preparer.rb

References:

https://api.rubyonrails.org/classes/ActiveJob/QueueAdapters.html
https://github.com/collectiveidea/delayed_job#named-queues