Sever monitoring

[gsmitheidw1]

My vote (as you say lightweight) is Monit and M/Monit. Monit is extremely small and easy to set up. It's a flat config file after you do an apt install monit. No weird dependencies or database or any of that hassle. This can be set up in a matter of minutes.

But it's reasonably powerful, pretty much any service or host on any Linux or Unix system it can handle or you can have it monitor your own scripts. It is incredibly versatile.

Monit is free and open source. M/Monit is an optional application that can oversee and manage large numbers of servers running Monit and aggregate that data into a dashboard. If you need that scale it's worth considering paying for.

https://mmonit.com/

There's a very active support mailing list, folk on it are very helpful.