问题
So I know Heroku's free dynos 'wind down' when there isn't any traffic to them– how would this effect the cron jobs that I've implemented using the node-cron module?
回答1:
Jobs scheduled by node_cron won't run when your free dynos are sleeping.
As an alternative, you can use the Heroku Scheduler add-on to schedule your cron jobs. That will trigger one-off dynos to run your cron jobs. Provided you don't exceed your monthly allowance of free dyno hours, you will be able to run your cron jobs for free.
回答2:
Probably they won't work as you expect in 100%. I mean, if cron execution will be scheduled at the time when your server would be offline, then it won't work. Hobby Dynos on Heroku power-up only at HTTP request and shutdown after some period of inactivity, they won't boot because of cron.
来源：https://stackoverflow.com/questions/39057883/heroku-and-node-cron