My own server? YOLO

At work? Grafana, KOBS, Victoria Metrics, Jaeger, OpsGenie, ...

My clients when they text me the server is down.

"Huh weird, I tried to use and it's not working. Welp, guess I better fix it..."

I'm a huge fan of Netdata, very configurable and monitors just about anything you could want. Great interface and alerts too - https://www.netdata.cloud/

I just use homepage as my homepage :D

I can see simple CPU/RAM/storage stats and got widgets for almost all services, one of them is portainer so I can see if any service is stopped (most of them are running in docker). Also few services send notification on error or update

I know its not really a monitoring tool, but it works well enough for me

Node exporter on hosts, OpenTelemetry collector to scrape metrics and collect logs, shipping them to Prometheus and Loki, visualising with Grafana.

Day job is for an observability platform where we heavily encourage the use of (and also contribute) to the OpenTelemetry collector project, hence my use of it.

Zabbix for agent / snmp based statistics.

Uptime Kuma for up/down states with a webhook notification into Discord so I get instant alerts on my phone when one goes down.

How has nobody in this thread said check_mk yet?

It's free, you host it yourself. It's built off of nagios, compatible with nagios plugins, supports snmp or agent based checks. It can email, SMS, slack or discord you when something breaks, you can write your own custom checks in any language that can output to a local console... I could never imagine even looking for something else.

I like monit. It’s simple to setup and pretty flexible.

https://mmonit.com/monit/

I've been using uptime Kuma recently and it's great but works better outside of docker.

Inside docker I'd get a lot of false down positives from I assume docker throttling the checks.

Plus it works with email, telegram, and matrix chat alerts. I monitor all my clients sites with it, and it's bullet proof behind caddy.

At home, nagios, at work colleagues. (I finally escaped the admin rat race)

At home, libreNMS. Just SNMP everything.

For work, whatever the tool of the day is from management.

Grafana set up to run on the server locally, then I connect to it via SSH forwarding. Then I can view all kinds of metrics in my browser in a neat interface.

Zabbix

Prometheus and Altertmanager

Btop and logwatch with logrotate. I use healthchecks to check if the server is unreachable and it notifies me.

I use collectd and graphs on my openwrt router. It can even use data from mqtt-connected thermometers and gather metrics from other collectd instances.

Grafana, fronting information from Prometheus, Loki and Telegraf/influxdb since I'm used to that from work and has been a bit more set and forget compared to node_exporter. Easier to add in plugins as well instead of a new container/service to scrape.