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Richard Wynn
Richard Wynn

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3 Task Scheduling Packages for Node.js

#node #javascript #webdev #scheduling

⏳ 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 like cron. In this article, I will show you top 4 task scheduling packages that emulate cron-like functionality for Node.js apps.

Node Cron

The node-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 install node-cron by using npm.

$ npm install --save node-cron
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Examples 

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

$ npm install node-schedule
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Examples 

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

$ npm install agenda
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You will also need a working Mongo database (v3) to point it to.

CJS / Module Imports

For regular javascript code, just use the default entrypoint

const Agenda = require('agenda');
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For Typescript, Webpack or other module imports, use agenda/es entrypoint:

import { Agenda } from 'agenda/es';
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NOTE:

  • If you're migrating from @types/agenda you also should change imports to agenda/es.
  • Instead of import Agenda from 'agenda' use import Agenda from 'agenda/es'.

Examples 

const mongoConnectionString = "mongodb://127.0.0.1/agenda"; const agenda = new Agenda({ 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) => { await User.remove({ lastLogIn: { $lt: twoDaysAgo } }); }); (async function () { // IIFE to give access to async/await await agenda.start(); await agenda.every("3 minutes", "delete old users"); // Alternatively, you could also do: await agenda.every("*/3 * * * *", "delete old users"); })();
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agenda.define( "send email report", { priority: "high", concurrency: 10 }, async (job) => { const { to } = job.attrs.data; await emailClient.send({ to, from: "example@example.com", subject: "Email Report", body: "...", }); } ); (async function () { await agenda.start(); await agenda.schedule("in 20 minutes", "send email report", { to: "admin@example.com", }); })();
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(async function () { const weeklyReport = agenda.create("send email report", { to: "example@example.com", }); await agenda.start(); await weeklyReport.repeatEvery("1 week").save(); })();
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👋 And you? Have you ever used any of these packages or another packages to do cron stuff in Node.js? Feel free to put a comment below 😃

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