The PingDataMetrics Server collects three types of metrics:

Count metrics
Represent the number of times a specific event happens within the server. Examples of count metrics include the number of LDAP operations performed, network packets received, or new connections established.
Continuous-valued metrics
Measure things that always have a value. For example, these metrics include the amount of free disk space, the current number of connected clients, and the number of operations pending in the work queue.
Discrete metrics
Correspond to measurements that have both a value and a weight, such as the duration of an LDAP operation or the average duration of a checkpoint.

The statistics that can be applied to values depend on the metric type. Only count statistics are available for count metrics. Discrete metrics have count, average, and histogram statistics available, which expose a count of the values broken down into bucket ranges. Average, minimum, and maximum statistics are available for continuous-valued metrics.