@shitpisscum @dcc @MK2boogaloo @Zerglingman @istvan @sysrq

> how do you actually do heartbeat monitoring (not just cron) without using some party solution like this?

There are a lot of solutions for this, Prometheus, etc., or rolling your own.

> and I want to receive real time notifications (email/SMS/whatever) whenever one of them fails/

SMS gateway, Twilio or whatever. You can't really get into the phone system without a third party being involved: at least the phone company will be involved. But you could always just get a 4G USB modem and an extra SIM card and send yourself SMS like that, root an Android phone, whatever.

It's much easier to send yourself an email, especially if you're talking about cron. Just set up an MTA to handle the local local spool by sending it to your regular mail server (as long as that server accepts the other server as a relay).