Redcron

A drop in replacement for the Strapi cron plugin that uses Redlock to prevent multiple instances of Strapi from running the same cron job at the same time.

Table of Contents

• Table of Contents
• ✨ Features
• 🤔 Motivation
• 🖐 Requirements
• ⏳ Installation
• 🔧 Configuration
  • Minimal Configuration
  • Full Configuration
• 🚚 Usage
  • Example
  • Bootstrap Example
• Contributing
• License
• ⭐️Did you find this helpful?
• Links

✨ Features

Drop-in* replacement for the Strapi cron plugin that uses Redlock to prevent multiple instances of Strapi from running the same cron job at the same time.

* requires minimal configuration

🤔 Motivation

Currently, if you horizontally scale Strapi and use the cron feature, you will end up with multiple instances of Strapi running the same cron job at the same time, potentially causing race conditions. This can cause issues with your database or other services that you are trying to integrate with.

🖐 Requirements

Install and configure the Strapi Redis Plugin

This plugin needs to be registered and configured before the cron plugin.

⏳ Installation

# Using Yarn (Recommended)
yarn add strapi-plugin-redcron

# Using npm
npm install strapi-plugin-redcron --save

🔧 Configuration

Minimal Configuration

module.exports = {
  redis: {
    // your redis config
  },
  redcron: {
    enabled: true,
  },
}

Full Configuration

module.exports = {
  redis: {
    // your redis config
  },
  redcron: {
    config: {
      redlockConfig: {
        driftFactor: 0.01,
        retryCount: 10,
        retryDelay: 200,
        retryJitter: 200,
      },
      lockDelay: null,
      lockTTL: 5000,
      debug: false,
    },
    enabled: true,
  },
}

🚚 Usage

Adding the bypassRedcron property to your cron job will bypass the redlock logic and allow multiple instances of Strapi to run the same cron job at the same time.

This plugin requires you to use the object format of the cron config. i.e if you are using the rule as the key, you will need to change it to an object with the rule as a property and the key as a unique name. This is because across your Strapi instances, Redis needs to lock onto a key that is the same across all instances.

If you need assistance understanding the cron syntax check out CronTab Guru.

Example

// path: ./config/cron-tasks.js

module.exports = {
  myJob: {
    task: ({ strapi }) => {/* Add your own logic here */ },
    bypassRedcron: false, // optional
    options: {
      rule: '0 0 1 * * 1',
    },
  },
};

Bootstrap Example

bootstrap({ strapi }) {
  strapi.cron.add({
    myJob: {
      task: async ({ strapi }) => {
        console.log("hello from bootstrap")
      },
      bypassRedcron: false, // optional
      options: {
        rule: '*/10 * * * * *',
      }
    },
  })
},

Contributing

Feel free to open a PR if you want to contribute to this project.

You can spin up a new Redis cluster for testing by running docker-compose up in the root of the project. You can run Strapi multiple strapi instances at the same time by adding server.js to the root of your wrapper project

//server.js
'use strict';

// Start Strapi
const strapi = require('@strapi/strapi');
strapi().start();

and running

pm2 start --name="mystrapiapp" server.js -i 2

License

See the LICENSE file for licensing information.

⭐️Did you find this helpful?

If you found this plugin helpful give it a star?

Links

• NPM Package
• Github
• MIT License