The Controller applies its own limits on metric registration. For an on-premises Controller, you can view and modify the properties that control the metric registration limit in the Controller settings page in the Controller Administration Console.

The relevant Controller settings are:

• metric.registration.limit: The maximum number of metrics that can be registered for an account in the Controller. The default is 2 million.
• application.metric.registration.limit: The maximum number of metrics that can be registered for a business application in the Controller. The default is 1 million.