Done, I've succesfully set up #Prometheus and #Grafana on the same machine as my Mastodon instance
as encouraged by @NotMyBub
Followed this great article https://jaanus.com/mastodon-monitoring-prometheus-grafana/ from @jaanus
Used the cool Grafana dashboard from @IPngNetworks https://grafana.com/grafana/dashboards/17492-mastodon-stats/
Now I'd like more Mastodon stats (number of posts, instances, etc) like they have in: https://grafana.hachyderm.io/public-dashboards/445bbb0e169f4e86b1d1eeee7e50c92a?orgId=1&refresh=30s