What we learned about configuring Sidekiq from GitLab.com

What this post added

This post details the configuration of Sidekiq for large deployments on GitLab.com, focusing on addressing Redis CPU saturation. It explains the historical 'one queue per worker' approach and its limitations with a large number of queues. The post then describes the shift to a 'one queue per shard' model using Sidekiq routing rules, which significantly reduces Redis overhead by simplifying job fetching. It also touches upon Sidekiq's concurrency and threading model in Ruby.