How to run cron job at a random time in node js?

Question

There are many questions related to my question but none that I could find are for node js such as this one, in addition, I would like to know how to run a cron job at a random time within a period every period, for my particular use I would like to run a cron job at a random time within an hour every hour. For example the random time between 10:00-11:00 is 10:15 then the random time between 11:00-12:00 is 11:53, and so on.

Set your cron to 10:00 ans add random timeout. It's what is done in the answers to the question you linked — Konrad, Nov 28 '22 at 08:28
I've solved this but getting random delay(between the minimum(0) and maximum time(60*60 = 3600)) in the cron job's callback and sleeping for that random amount of seconds before proceeding with the callback. — MShakeG, Nov 30 '22 at 15:29

score 0 · Answer 1 · edited Feb 01 '23 at 16:11

function scraper() {
  // do something here
}

// CronJob runs function every hour at minute 0 second 0
const scraperTimer = new CronJob('0 0 */1 * * *', function () {
  // set random delay between 5(min) and 50(max) minutes
  const delay = Math.floor(Math.random() * (3e6 - 300000) +   300000);

  setTimeout(() => {
    scraper();
  }, delay);

  console.log(`running scraper in ${delay / 60000} minutes`);
});

scraperTimer.Start()

It would be good to be cautious of scope when using Cron and timers, memory leaks can happen.

How to run cron job at a random time in node js?

1 Answers1