metrics

type ResponseMetric interface {
	// ObserveLatency observes latency.
	ObserveLatency(url string, seconds float64)
	// ObserveFailure observes failure response.
	ObserveFailure(url string, now time.Time, seconds float64, err error)
	// ObserveReceivedBytes observes the bytes read from apiserver.
	ObserveReceivedBytes(bytes int64)
	// Gather returns the summary.
	Gather() types.ResponseStats
}