As part of changing hardware to a Raspberry Pi I decided that now was a good time to start looking at metrics for the server to make sure it could keep up with what people were doing. As part of that the server now has a graph of metrics (https://grafana.3decibels.net/grafana/d/fQVgSeX7z/minecraft?orgId=1&refresh=30s) you can check out. The most important graph is probably the on for Minecraft Tick Lag. It will log whenever the Minecraft server starts complaining that it is falling behind on processing.
Enjoy!
--3dB