Most of the base images in the Docker registry do not offer immutable tags. This means that if you’re building your Docker image based on, for example, an official Ruby image
ruby:3.3.0-slim, it might change overnight, and the machines that have already downloaded this tag will never receive an updated image.
Now and then you receive a report about something not working as expected. This time it was scarier than usual: a job, killed by Docker after consuming too much memory with an OOM error, was disappearing from the queue without a trace. In production, we deploy
sidekiq-profor its reliability guarantees, specifically
super_fetchstrategy for pulling work from the queue, and normally should re-queue the job after a restart.