Custom metrics refer to any metrics that are not part of our regular integration suite, for example using custom checks or API-level metrics in your application stack. To clarify, integrations that can potentially emit an unlimited number of metrics to us can also count as custom metrics (e.g: JMX / WMI / Nagios / Cacti/ SNMP).
Pro plans include 100 custom metrics per host and Enterprise plans include 200 custom metrics per host. This number is averaged across all paid hosts. Additional custom metrics packages can be purchased. Existing customers can contact Customer Success. New customers can contact Sales.