I’ve been trying Netdata on a few of my servers, and it’s awesome. Real-time monitoring of Linux servers (collects thousands of metrics every second) but somehow has very low CPU usage. Really cool.
I was previously using Munin, which runs every 5 minutes and causes a big jump in CPU usage whenever it runs. Netdata is much more precise, useful and collects much more data, yet uses significantly less CPU power.
I have it up here if you want to see a demo: https://netdata.vps03.d.sb/
The only downside I’ve seen is that it’s only focused on realtime monitoring, so it only keeps an hour of data default. It keeps it all in RAM (~15 MB for an hour of data for 1000 metrics). It’s amazing for that use case though. For long-term monitoring, you can stream the data into a time series database. I’m using Prometheus with 120-day retention to track longer-term trends, and it’s working really well.