JavaScript

Scheduling jobs on a Sails.js application

In one of my projects there was the need to put scheduled tasks on my Sails.js application. Agenda and node-schedule are the tools of my choice when scheduling jobs on a node.js app. What we are gona cover is adding scheduling to our Sails.js application using node-schedule and agenda.

To get started let’s create our application

sails new SailsScheduling
cd SailsScheduling

My approach to use node-schedule is to add some configuration on the bootstrap.js file.

npm install node-schedule --save

We will add a service to our Sails.js application. Services on a Sails.js application reside on the api/services/ path. Suppose that we implement a service that will send emails

/**
 * Created by gkatzioura on 6/20/16.
 */

var send = function (text,callback) {

  sails.log.info("Should send text: "+text)
  callback();
};

module.exports =  {
  send: send
}

Then we add our job triggering code on bootstrap.js.

/**
 * Bootstrap
 * (sails.config.bootstrap)
 *
 * An asynchronous bootstrap function that runs before your Sails app gets lifted.
 * This gives you an opportunity to set up your data model, run jobs, or perform some special logic.
 *
 * For more information on bootstrapping your app, check out:
 * http://sailsjs.org/#!/documentation/reference/sails.config/sails.config.bootstrap.html
 */
var scheduler = require('node-schedule');

module.exports.bootstrap = function(cb) {

  // It's very important to trigger this callback method when you are finished
  // with the bootstrap!  (otherwise your server will never lift, since it's waiting on the bootstrap)

  var emailService = EmailService;


  var minuteJob  = scheduler.scheduleJob('* * * * *', function(){
    EmailService.send("Random text",function (err, result) {
      sails.log.info("Job executed")
    });
  });

  cb();
};

The next example would use agenda. Instead of rolling out our own configuration we will use sails-hook-jobs which integrates wonderfully to our sails application as a grunt task.

npm install mongodb@~1.4 --save
npm install sails-hook-jobs --save

We need mongodb 1.4 version for mongo-skin.

Agenda is backed by mongodb. For docker users you can issue

docker run --name some-mongo -d mongo

and have a mongodb server up and running.

Next step is creating the file config/jobs.js containing the configuration.

/**
 * Default jobs configuration
 * (sails.config.jobs)
 *
 * For more information using jobs in your app, check out:
 * https://github.com/vbuzzano/sails-hook-jobs
 */

module.exports.jobs = {

  // Where are jobs files
  "jobsDirectory": "api/jobs",

  // agenda configuration. 
  // for more details about configuration,
  // check https://github.com/rschmukler/agenda
  "db": { 
    "address"    : "localhost:27017/jobs",
    "collection" : "agendaJobs" 
  },
  "name": "process name",
  "processEvery": "10 seconds",
  "maxConcurrency": 20,
  "defaultConcurrency": 5,
  "defaultLockLifetime": 10000
};

Next step is to create the directory jobs on our api folder. In order to add a job we should create a javascript source file on the api/jobs folder. You file should have the ending Job.js. Pay special attention to this, you do not want to spend hours on figuring out what went wrong like I did.

Our job would send an email every five minutes.

module.exports = function(agenda) {
  var job = {

    frequency: 'every 5 minutes',
    run: function(job, done) {
      EmailService.send("Test email",function (err,result) {

        if(err) {
          sails.log.error("Job was not executed properly");
          done(err);
        } else {
          sails.log.info("Agenda job was executed");
          done();
        }
      });
    },
  };
  return job;
}

All in all there are definitely more tools out there for Sails.js scheduling. My personal choice is agenda, due to its approach on managing your jobs and integrating as a sails task.

You can find the source code on github.

Reference: Scheduling jobs on a Sails.js application from our WCG partner Emmanouil Gkatziouras at the gkatzioura blog.

Emmanouil Gkatziouras

He is a versatile software engineer with experience in a wide variety of applications/services.He is enthusiastic about new projects, embracing new technologies, and getting to know people in the field of software.
Subscribe
Notify of
guest

This site uses Akismet to reduce spam. Learn how your comment data is processed.

0 Comments
Oldest
Newest Most Voted
Inline Feedbacks
View all comments
Back to top button