NewCounter creates a new counter metric, without any labels.

NewCounterGroup creates a new counter group with a set of labels, where each unique combination of labels becomes its own counter.

NewGauge creates a new counter metric, without any labels.

NewGaugeGroup creates a new gauge group with a set of labels, where each unique combination of labels becomes its own gauge.

CounterConfig configures a counter.

GaugeConfig configures a gauge.