debian-mirror-gitlab/doc/development/sidekiq_style_guide.md

Sidekiq Style Guide

This document outlines various guidelines that should be followed when adding or modifying Sidekiq workers.

Default Queue

Use of the "default" queue is not allowed. Every worker should use a queue that matches the worker's purpose the closest. For example, workers that are to be executed periodically should use the "cronjob" queue.

A list of all available queues can be found in config/sidekiq_queues.yml.

Dedicated Queues

Most workers should use their own queue. To ease this process a worker can include the DedicatedSidekiqQueue concern as follows:

class ProcessSomethingWorker
  include Sidekiq::Worker
  include DedicatedSidekiqQueue
end

This will set the queue name based on the class' name, minus the Worker suffix. In the above example this would lead to the queue being process_something.

In some cases multiple workers do use the same queue. For example, the various workers for updating CI pipelines all use the pipeline queue. Adding workers to existing queues should be done with care, as adding more workers can lead to slow jobs blocking work (even for different jobs) on the shared queue.

Tests

Each Sidekiq worker must be tested using RSpec, just like any other class. These tests should be placed in spec/workers.

Removing or renaming queues

Try to avoid renaming or removing queues in minor and patch releases. During online update instance can have pending jobs and removing the queue can lead to those jobs being stuck forever. If you can't write migration for those Sidekiq jobs, please consider doing rename or remove queue in major release only.