Posted onMay 28, 2021

3 Task Scheduling Packages for Node.js

⏳ Task scheduling allows you to schedule your code to be executed at a scheduled date/ time, at recurring intervals, or once after a specified interval. In Linux, this is often handled by packages likecron. In this article, I will show you top 4 task scheduling packages that emulate cron-like functionality for Node.js apps.

Node Cron

Thenode-cron module is tiny task scheduler in pure JavaScript for node.js based on GNU crontab. This module allows you to schedule task in node.js using full crontab syntax.

Popularity

1.449.775 Weekly Downloads (Up to the time of this article)

Installation

You can installnode-cron by usingnpm.

$ npm install --save node-cron

Examples

var cron = require('node-cron');cron.schedule('* * * * *', () => {  console.log('running a task every minute');});

Node Schedule

Node Schedule is a flexible cron-like and not-cron-like job scheduler for Node.js. It allows you to schedule jobs (arbitrary functions) for execution at specific dates, with optional recurrence rules. It only uses a single timer at any given time (rather than reevaluating upcoming jobs every second/ minute).

Popularity

1.941.398 Weekly Downloads (Up to the time of this article)

Installation

You can installnode-schedule by usingnpm.

$ npm install node-schedule

Examples

const schedule = require('node-schedule');const job = schedule.scheduleJob('42 * * * *', function(){  console.log('The answer to life, the universe, and everything!');});

Agenda

Agenda is a light-weight job scheduling library for Node.js that offers:

Minimal overhead. Agenda aims to keep its code base small.
Mongo backed persistence layer.
Promises based API.
Scheduling with configurable priority, concurrency, and repeating.
Scheduling via cron or human readable syntax.
Event backed job queue that you can hook into.

Popularity

55.774 Weekly Downloads (Up to the time of this article)

Installation

npm

You can installagenda by usingnpm.

$ npm install agenda

You will also need a workingMongo database (v3) to point it to.

CJS / Module Imports

For regular javascript code, just use the default entrypoint

constAgenda=require('agenda');

For Typescript, Webpack or other module imports, useagenda/es entrypoint:

import{Agenda}from'agenda/es';

NOTE:

If you're migrating from@types/agenda you also should change imports toagenda/es.
Instead ofimport Agenda from 'agenda' useimport Agenda from 'agenda/es'.

Examples

constmongoConnectionString="mongodb://127.0.0.1/agenda";constagenda=newAgenda({db:{address:mongoConnectionString}});// Or override the default collection name:// const agenda = new Agenda({db: {address: mongoConnectionString, collection: 'jobCollectionName'}});// or pass additional connection options:// const agenda = new Agenda({db: {address: mongoConnectionString, collection: 'jobCollectionName', options: {ssl: true}}});// or pass in an existing mongodb-native MongoClient instance// const agenda = new Agenda({mongo: myMongoClient});agenda.define("delete old users",async(job)=>{awaitUser.remove({lastLogIn:{$lt:twoDaysAgo}});});(asyncfunction(){// IIFE to give access to async/awaitawaitagenda.start();awaitagenda.every("3 minutes","delete old users");// Alternatively, you could also do:awaitagenda.every("*/3 * * * *","delete old users");})();

agenda.define("send email report",{priority:"high",concurrency:10},async(job)=>{const{to}=job.attrs.data;awaitemailClient.send({to,from:"example@example.com",subject:"Email Report",body:"...",});});(asyncfunction(){awaitagenda.start();awaitagenda.schedule("in 20 minutes","send email report",{to:"admin@example.com",});})();

(asyncfunction(){constweeklyReport=agenda.create("send email report",{to:"example@example.com",});awaitagenda.start();awaitweeklyReport.repeatEvery("1 week").save();})();