Is there a way to run a process at startup on Express.js?
I want to run a continuous process that will execute every 30 minutes, but it should run always and start running when Express applications is started.
You can set up a cron task in nodejs. You need to set crontab on the server to call a path in node every 30 minutes and then have the path execute the task required.
app.get('/cron', function(req, res){
runPeriodicTask();
return;
});
Related
I have a simple node-cron schedule that calls a function:
cron.schedule('00 00 00 * * *', () => {
console.log('update movies', new Date().toISOString());
updateMovies();
});
When I log in to my server using PuTTy or use the droplet console in Digital Ocean and then run the updateMovies.mjs file node server/updateMovies.mjs and wait for the time that the cron-job should run, everything works as expected.
But when I close PuTTy or the droplet console in Digital Ocean, then nothing happens when the cron-job should run. So the server seems to lose the cron-job when I close the session.
Short answer
You need to run the app in the background
nohup node server/updateMovies.mjs >/dev/null 2>&1
Long answer
Run your app directly in the shell is just for demos or academic purposes. On an enterprise environment you should a live process like a server which runs independently of the shell user.
Foreground and background processes
Processes that require a user to start them or to interact with them are called foreground processes
Processes that are run independently of a user are referred to as background processes.
How run background process (Linux)
No body uses windows for an modern deployments, so in Linux the usual strategy is to use nohup
server.js
var express = require('express');
var app = express();
app.get('/', function(req, res) {
res.type('text/plain');
res.send('Hell , its about time!!');
});
app.listen(process.env.PORT || 8080);
nohup node server.js >/dev/null 2>&1
If you login to the server using some shell client, and run only node server.js it will start but if you close the shell window, the process will ends.
How run background process with nodejs and PM2
pm2 server.js
More details here:
https://pm2.keymetrics.io/docs/usage/quick-start/
Best way : Docker
You need to dockerize your app and it will run everywhere with this command:
docker run -d my_app_nodejs ....
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 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.
Is it possible to run gulp task as crone job on Apache server i have gulp.js and some tasks like this
gulp.task('image-compress', function() {
gulp.src('./img/**/*{css,png,jpg,gif}')
.pipe(imagemin())
.pipe(gulp.dest('./img'));
}
);
The problem is that i can start it on my machine, but user will add a lot of more pictures on CMS, and i need to optimize those pictures, lets say once a day?
The question is not about this task, it is how to start gulp on production shared hosting server, that i can not access command line :(
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).