I have nagios, Prometheus, and Zabbix all installed. I am ready to be the !monitoring guy!

At some point, I need to set up the #ElasticStack, #FluentD, and #Grafana, but Grafana in particular I don't see as a monitoring tool. It is a visualization tool. It is often in the stack with Prometheus, and I need to know it, but I don't see it as a priority. The priority is to get Prometheus monitoring my #Cassandra install.