NewGauge constructs a new Gauge.

NewHistogram constructs a new Histogram.

NewRate creates a new rate metric.

NewRegistry creates a new Registry.

NewTimer constructs a new Timer using an exponentially-decaying sample with the same reservoir size and alpha as UNIX load averages.

Gauge hold an int64 value that can be set arbitrarily.

Histogram calculate distribution statistics from a series of int64 values.

Rate tracks the rate of values per second.

Registry is a registry of all metrics.

Timer capture the duration and rate of events.