Cron Job Functionality In Nodejs

Posted By : Vivek Joshi | 03-Jul-2017

nodejs

For scheduling time specific jobs in nodejs we can use node-cron module using following steps

step 1:- first we install node-cron module from npm

npm install --save node-cron

step 2:- create a function for scheduleling cron jobs

Step 3:- create function and schedule crone jobs

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

in cron's schedule function '*' are define different time period these are follow and make sure do define the * as same format separate with space.

* * * * * *

from left to right

* second (optional)

* minute

* hour

* day of month

* month

* day of week

field	value
second	0-59
minute	0-59
hour	0-23
day of month	1-31
month	1-12 (or names)
day of week	0-7 (or names, 0 or 7 are sunday)

these are the some example for scheduling jobs for different time periods

function scheduleJosbs(){
 var cron = require('node-cron');
//in schedule function first * is optional it is use for defining seconds if you are not working on seconds jobs 
//so you can define only five '5' starts which is start from minutes
cron.schedule('* * * * * *', function(){
 console.log('running a task every second'); });
 cron.schedule('1,2,4,5 * * * *', function(){
 console.log('running every minute 1, 2, 4 and 5');
 });
 cron.schedule('1-5 * * * *', function(){ 
console.log('running every minute to 1 from 5'); 
}); 
cron.schedule('*/2 * * * *', function(){
 console.log('running a task every two minutes');
 });
 cron.schedule('* */2 * * *', function(){ 
//this job will run in every two hours in this hour it will run every minutes (e.g 2:1,2:2 ) because we have define minutes as *; 
//if you want to run this job only once in two hours so you have to define minutes also (e.g '0 */2 * * *' run once in every two hours
 console.log('running a task every two hours'); 
}); 
cron.schedule('* * * January,September Sunday', function(){
 //you can define sort name of months and days(e.g ('* * * jan,sep sun') 
//and number of months and days
console.log('running on Sundays of January and September');
});
}