Heroku workers for node.js

Question

I am starting with Heroku and I have a webapp that has a part that needs to run once every week (Mondays preferably). I had been reading something about workers: here and here and here... But I still have many doubts:

1) This workers, runs on background without a strict control, can´t be scheduled to run once a week. or am I wrong? If I am wrong how can I schedule it?

2) To make them work, what exactly do I need to do? Type

 web:     node webApp.js
 worker:  node worker.js

in the Procfile (where worker.js is the part of the program that needs to run only once a week). And that is all?? nothing else?? so easy??

3) And the last one... but the most important. The "squamous matter of money"... One dyno is the same as one worker, so if you have a dyno running for the web you need to buy another for the worker... no? And on the list of prices a extra dyno cost 34.5$ (27.87€). It isn´t cheap... so I want to know if I am right, is it necessary buy a dyno if you want to run a worker?

Answer 1

You might find that the Heroku Scheduler add-on (https://devcenter.heroku.com/articles/scheduler) is a 'good enough' low cost option. You are charged for the hours that your scheduled tasks run for so if you have a regular job that only takes a short time to run it would work out much cheaper than a continuous worker process.

Its not as flexible with regard to scheduling as other options. It can be set up to run a task at a specific time every day or hourly. So if you need to have your task run say only on Mondays then you would need to have the scheduler run daily then check the day within your worker.js and exit immediately on other days.