Delayed Job

What it does

Failed-job handling

Failed jobs are deleted by default after retries, but the worker can be configured to keep them in the database.checked 5 Oct 2026

Purpose

Delayed::Job is a database-backed priority queue for running longer tasks asynchronously in the background.checked 5 Oct 2026

Queueing

Methods can be queued with `.delay`, with options for priority, scheduled run time, and named queues.checked 5 Oct 2026

Rails integration

Rails 4.2 and later can use Delayed::Job as the Active Job queue adapter.checked 5 Oct 2026

Requirements

The current gem specification requires Ruby 3.2 or later and ActiveSupport 3.0 or later but below 9.0.checked 5 Oct 2026

Retry behavior

Failed jobs are rescheduled with a delay based on the attempt count, and the default maximum is 25 attempts.checked 5 Oct 2026

Runtime limit

The default maximum job runtime is four hours; the documentation warns that a longer job could be picked up by another computer.checked 5 Oct 2026

Security and warranty

The MIT license grants use, copying, modification, distribution, sublicensing, and sale, and provides the software as-is without warranty.checked 5 Oct 2026

Storage backends

The documentation describes Active Record and Mongoid backends for storing the job queue.checked 5 Oct 2026

Support

The README points users to a Google Groups mailing list and Stack Overflow for help.checked 5 Oct 2026

Use cases

The project lists newsletter sending, image resizing, HTTP downloads, batch imports, and spam checks among its uses.checked 5 Oct 2026

Workers

Background workers can be started as separate processes and assigned to specific queues or worker pools.checked 5 Oct 2026