I want a Nodejs application running on Heroku to run a task every 30 seconds. I use Heroku scheduler for another task but that's because it runs once a day and Scheduler seems fine for that, but to run at this interval it is not suitable.
So I have installed node-cron and setup a job that would run every 30 seconds, daily, between 11am and 6pm (I am basically calling an api and then updating a database), locally I can run this fine with node cron.js
cron.js
const cron = require('node-cron');
const task = require('./scripts/task');
cron.schedule('*/30 * 11-18 * * *', () => {
console.log('Running Function');
task.runFunction();
});
I'm not 100% sure how to run this on Heroku, from their docs they specify this kind of setup (configured in Procfile):
web: node web.js
worker: node worker.js
clock: node clock.js
Current Procfile
web: node server.js
Is it a case of changing my cron.js to clock.js ? and then having something in a worker.js file? (though unsure as to what).
You should probably change the clock.js to cron.js, or, as you say, rename cron.js to clock.js.
web: node web.js
worker: node worker.js
clock: node cron.js
Also, I'm not sure your cron.js is set up correctly. From the documentation on node-cron, it looks like you might need something that looks like this:
const CronJob = require('../lib/cron.js').CronJob;
console.log('Before job instantiation');`
const job = new CronJob('*/30 * 11-18 * * *', () => {
console.log('Running Function');
task.runFunction();
});
console.log('After job instantiation');
job.start();
You don't need this line worker: node worker.js if in your cron.js you don't tell him to do somethings with this worker. (I don't know what runFunctions() do). And you don't even need to add the first line if your application is just cron jobs.
So you can just have this Profile :
clock: cron.js
You can change clockto cron if you want. It doesn't mean: docs.
Related
i have created the cron job using node js ,which have to run in the interval of every hour even if the system is shut down. It has to run automatically with out manual invoke of the code .Please help to solve this
i have tried with pm2 but not working as expected.
First you should install npm package for crone-job
npm i node-cron
And then you can follow this code for your automatic job
const schedule = require("node-cron");
schedule.scheduleJob("00 02 * * *",
function () {
console.log("The answer to life, the universe, and everything!");
expected_Function_Name();
});
You will get your function output in every day 2pm.
I want to write a cron job on node.js which runs every minute. The tutorials that I viewed online all showed the cron job being written in the "App.js" or "server.js" file which is the main file on nodejs.
I want to seperate this into another file for better readability but I cannot find any solution or example online. please help.
I want to write this in a separate file just like we write our routes.
const cron = require("node-cron");
cron.schedule("* * * * *", function() {
console.log("running a task every minute");
});
You can create and export javascript modules elsewhere in your express/node.js app like this:
app.js
const express = require('express');
const app = express();
const port = 5000;
require('./tasks/tasks')();
app.listen(port, () => {
console.log(`App listening at http://localhost:${port}`)
});
tasks.js
const cron = require('node-cron');
module.exports = () => {
cron.schedule('* * * * *', () => {
console.log('running a task every minute');
});
}
Terminal:
[nodemon] starting `node start app.js`
App listening at http://localhost:5000
running a task every minute
File Structure:
/tasks
tasks.js
app.js
yes. you can write your cron-job in separte file. when starting the server, you can invoke your cron job, like in your app.js or server.js. you just export your cron job file & impore here
import cronJob from "../filename.js"
server.listen(3000, () => {
cronJob.start();
});
node-cron emulates, rather than uses, the UNIX / Linux / FreeBSD cron subsystem driven by crontab file entries. node-cron projects the illusion that functions in a running nodejs instance can be scheduled as if they were executable programs.
If you want to schedule a different nodejs program as a cron job, don't use node-cron, use cron. Put an entry in the OS's crontab mentioning the nodejs program.
I am trying to run a node script with cron every minute. I dont believe it is running at all. When I run grep cron /var/log/syslog I dont see it running in the log.
Did I write the cron job wrong? If so how do I run a node script in a cron job?
* * * * * node /home/ubuntu/Server/nodeScript.js
Cron jobs don't run in a shell so you have to give the full path to the node binary.
/usr/bin/node (or whatever it is on that machine)
Try which node to find out
The easiest way to run it every single minute is just to put your code in endless loop with timeout.
For example
function yourCode () {
for {
// your code
timeout(60 * 1000)
}
}
function timeout(ms) {
return new Promise(resolve => setTimeout(resolve, ms));
}
Just be sure you run it with pm2 or supervisor so when it crashes it can restart automatically.
I have created a nodejs file using express enviornment and running the file on server using nodemon. Currently I have to give commands to the interface to run the particular file on nodemon but what I currently need is to schedule the task to run that file on server automatically at multiple occasion in a single day.
my file excute like this on terminal::
nodemon example_api.js
output terminal:
root#*********:/var/www/example project# nodemon example_api.js
[nodemon] ##.##.#####
[nodemon] to restart at any time, enter `rs`
[nodemon] watching: *.*
[nodemon] starting `node api.js`
Listening on port 8080
Note: I am currently running node js on Mobaxterm terminal currently using windows but my file will be run on a server with linux interface
1. If you want to run your node process continuously and want to run only particular task:
Use node-schedule or node-cron packages to run your code block at desired time or interval.
i.node-schedule
var schedule = require('node-schedule');
var j = schedule.scheduleJob('*/30 * * * * ', function(){
console.log('The answer to life, the universe, and everything!');
});
ii.node-cron
var cron = require('node-cron');
cron.schedule('*/30 * * * *', function(){
console.log('The answer to life, the universe, and everything!');
});
2. If you want to run only single node script:
You can use Linux crontab to execute your script at desired time
crontab -e
and add following entry
*/30 * * * * /usr/local/bin/node /home/ridham/example/script.js
This will execute /home/ridham/example/script.js every 30 minutes. and always give full qualified path here.
You have to give crontime in any of the following. you can learn about crontime here
For a simple implementation - you can just use setInterval like so:
setInterval(() => {
// do something every 5 seconds
}, 5000);
But it you want something like a cron, then, you might wanna go with node-cron or node-schedule.
You can also use providers like AWS CloudWatch. AWS CloudWatch allows you to run AWS Lambda functions on a cron.
I have Cronjob use node_module: node-cron
var hello = function( ) {
console.log('Hello world')
}
var job=new CronJob({cronTime:'00 52 13 * * *',
// that's important (100% made up example):
onTick: function() {
hello({
done: true,
lastRun: new Date()
});
},
start:false,timeZone:"America/Los_Angeles"});
job.start();
when I restart server .Cronjob not running.
node scripts that uses node-cron still have to be started for the cronjob to run. Adding things to node-cron, does not add it to cron on your machine, even though the naming can be confusing. node-cron simply allows your script to schedule jobs inside your script, while your script is running.
For this to work, either convert to scheduling the script on your machine, using the built in scheduler, or start your node script on machine startup. (This is different depending on your operating system).