How to schedule a job to run every hour with Sidekiq-Cron?

Use the cron expression '0 * * * *' in the job configuration, either in a YAML file or Ruby code. For example, in config/schedule.yml, set cron: '0 * * * *' for the job class to enqueue it hourly on the hour.

Sidekiq-Cron vs Rufus-Scheduler: which is better for Ruby apps?

Sidekiq-Cron is ideal for Sidekiq-integrated scheduling with multi-process safety via Redis, while Rufus-Scheduler is a standalone in-process scheduler better for simpler, single-process apps without Sidekiq dependencies. Choose based on your job processor and scaling needs.

Can Sidekiq-Cron handle jobs in different time zones?

Yes, you can specify time zones directly in cron expressions, like '0 22 * * 1-5 America/Chicago'. It evaluates against Rails' timezone or UTC by default, allowing flexible timezone support for global applications.

How to prevent duplicate jobs in multiple Sidekiq processes?

Sidekiq-Cron uses Redis coordination to ensure only the first process enqueues scheduled jobs, as described in its thread-safe multi-process support. This prevents duplicates across processes or nodes in distributed setups.

What happens to missed jobs during Sidekiq downtime?

By default, jobs missed within the last minute are caught up; you can adjust the reschedule_grace_period configuration (e.g., to 600 seconds for 10 minutes) to handle longer downtimes, such as during deployments, as noted in the under-the-hood section.

How to test Sidekiq-Cron schedules in Rails?

Use the testing example from the README: load the schedule file in your test suite (e.g., with RSpec) to check for valid cron strings and job classes, ensuring no errors and that all classes can be constantized and respond to perform_async.

Open-Awesome

sidekiq-cron

MITRubyv2.4.0

A scheduling add-on for Sidekiq that runs jobs at specified times using cron notation or natural language.

GitHub

1.9k stars302 forks0 contributors

What is sidekiq-cron?

Sidekiq-Cron is a Ruby gem that adds cron-based job scheduling to Sidekiq, allowing developers to schedule recurring background jobs using cron syntax or natural language. It solves the problem of automating periodic tasks—like sending nightly reports or cleaning up old data—within Sidekiq's ecosystem without relying on external cron daemons.

Target Audience

Ruby developers using Sidekiq for background job processing who need to schedule recurring tasks, such as sending periodic emails, generating reports, or performing regular database maintenance.

Value Proposition

Developers choose Sidekiq-Cron because it integrates directly with Sidekiq, supports multi-process safety to avoid duplicate jobs, offers flexible scheduling with natural language, and requires minimal configuration compared to managing separate cron systems.

Overview

Scheduler / Cron for Sidekiq jobs

Use Cases

Best For

Scheduling nightly report generation in a Rails application
Running periodic database cleanup or maintenance tasks
Automating recurring email campaigns or notifications
Enqueuing jobs at specific times with timezone support
Managing cron-like jobs within Sidekiq's existing infrastructure
Scheduling tasks with second-level precision (e.g., every 30 seconds)

Not Ideal For

Applications requiring event-driven or complex dependency-based job scheduling beyond simple time intervals
Projects not using Sidekiq or Ruby, as it's tightly coupled to the Sidekiq ecosystem
Environments where Redis is unavailable or undesirable for job coordination
High-frequency tasks needing sub-second precision without polling delays

Pros & Cons

Pros

Flexible Scheduling

Supports both standard cron syntax and natural language via Fugit, allowing expressions like 'every day at five' for intuitive configuration, as detailed in the scheduling options.

Multi-Process Safety

Uses Redis to coordinate across multiple Sidekiq processes, preventing duplicate job enqueuing and ensuring thread-safe operations, as explained in the thread-safe support section.

Declarative Configuration

Jobs can be defined in YAML files (e.g., config/schedule.yml), enabling easy management and automatic loading in Rails applications, highlighted in the YAML schedule files feature.

Integrated Web UI

Provides an optional web interface that integrates with Sidekiq's admin panel, allowing visualization and management of cron jobs without extra tools, as mentioned in the web UI integration.

Cons

Polling Latency

Checks for jobs every 30 seconds by default, causing potential delays for sub-minute schedules and requiring configuration tuning for second-precision jobs, which can be a bottleneck for high-frequency tasks.

Redis and Sidekiq Dependency

Heavily reliant on Redis for coordination and only compatible with Sidekiq, limiting flexibility and portability to other job processing systems, as it's designed exclusively for Sidekiq's ecosystem.

Namespace Management Issues

Changing namespaces can lead to duplicate jobs if not manually cleaned, and automatic namespace detection scales poorly, as admitted in the version 2.3 migration warnings about Redis load.

Frequently Asked Questions

Related Projects

Sidekiq

Simple, efficient background processing for Ruby

Stars13,534

Forks2,481

Last commit4 days ago

Whenever

Cron jobs in Ruby

Stars8,872

Forks719

Last commit3 months ago

Delayed Job

Database based asynchronous priority queue system -- Extracted from Shopify

Stars4,822

Forks948

Last commit5 months ago

Sucker Punch

Sucker Punch is a Ruby asynchronous processing library using concurrent-ruby, heavily influenced by Sidekiq and girl_friday.

Stars2,634

Forks109