Using histogram metrics instead of summary

pkg/util/workqueue/prometheus/prometheus.go

@@ -65,23 +65,25 @@ func (prometheusMetricsProvider) NewAddsMetric(name string) workqueue.CounterMet
 	return adds
 }
 
-func (prometheusMetricsProvider) NewLatencyMetric(name string) workqueue.SummaryMetric {
-	latency := prometheus.NewSummary(prometheus.SummaryOpts{
+func (prometheusMetricsProvider) NewLatencyMetric(name string) workqueue.HistogramMetric {
+	latency := prometheus.NewHistogram(prometheus.HistogramOpts{
 		Subsystem:   WorkQueueSubsystem,
 		Name:        QueueLatencyKey,
 		Help:        "How long in seconds an item stays in workqueue before being requested.",
 		ConstLabels: prometheus.Labels{"name": name},
+		Buckets:     prometheus.ExponentialBuckets(10e-9, 10, 10),
 	})
 	prometheus.Register(latency)
 	return latency
 }
 
-func (prometheusMetricsProvider) NewWorkDurationMetric(name string) workqueue.SummaryMetric {
-	workDuration := prometheus.NewSummary(prometheus.SummaryOpts{
+func (prometheusMetricsProvider) NewWorkDurationMetric(name string) workqueue.HistogramMetric {
+	workDuration := prometheus.NewHistogram(prometheus.HistogramOpts{
 		Subsystem:   WorkQueueSubsystem,
 		Name:        WorkDurationKey,
 		Help:        "How long in seconds processing an item from workqueue takes.",
 		ConstLabels: prometheus.Labels{"name": name},
+		Buckets:     prometheus.ExponentialBuckets(10e-9, 10, 10),
 	})
 	prometheus.Register(workDuration)
 	return workDuration

staging/src/k8s.io/client-go/util/workqueue/metrics.go

@@ -57,6 +57,11 @@ type SummaryMetric interface {
 	Observe(float64)
 }
 
+// HistogramMetric counts individual observations.
+type HistogramMetric interface {
+	Observe(float64)
+}
+
 type noopMetric struct{}
 
 func (noopMetric) Inc()            {}
@@ -73,9 +78,9 @@ type defaultQueueMetrics struct {
 	// total number of adds handled by a workqueue
 	adds CounterMetric
 	// how long an item stays in a workqueue
-	latency SummaryMetric
+	latency HistogramMetric
 	// how long processing an item from a workqueue takes
-	workDuration         SummaryMetric
+	workDuration         HistogramMetric
 	addTimes             map[t]time.Time
 	processingStartTimes map[t]time.Time
 
@@ -190,8 +195,8 @@ func (m *defaultRetryMetrics) retry() {
 type MetricsProvider interface {
 	NewDepthMetric(name string) GaugeMetric
 	NewAddsMetric(name string) CounterMetric
-	NewLatencyMetric(name string) SummaryMetric
-	NewWorkDurationMetric(name string) SummaryMetric
+	NewLatencyMetric(name string) HistogramMetric
+	NewWorkDurationMetric(name string) HistogramMetric
 	NewUnfinishedWorkSecondsMetric(name string) SettableGaugeMetric
 	NewLongestRunningProcessorSecondsMetric(name string) SettableGaugeMetric
 	NewRetriesMetric(name string) CounterMetric
@@ -214,11 +219,11 @@ func (_ noopMetricsProvider) NewAddsMetric(name string) CounterMetric {
 	return noopMetric{}
 }
 
-func (_ noopMetricsProvider) NewLatencyMetric(name string) SummaryMetric {
+func (_ noopMetricsProvider) NewLatencyMetric(name string) HistogramMetric {
 	return noopMetric{}
 }
 
-func (_ noopMetricsProvider) NewWorkDurationMetric(name string) SummaryMetric {
+func (_ noopMetricsProvider) NewWorkDurationMetric(name string) HistogramMetric {
 	return noopMetric{}
 }
 

staging/src/k8s.io/client-go/util/workqueue/metrics_test.go

@@ -155,11 +155,11 @@ func (m *testMetricsProvider) NewAddsMetric(name string) CounterMetric {
 	return &m.adds
 }
 
-func (m *testMetricsProvider) NewLatencyMetric(name string) SummaryMetric {
+func (m *testMetricsProvider) NewLatencyMetric(name string) HistogramMetric {
 	return &m.latency
 }
 
-func (m *testMetricsProvider) NewWorkDurationMetric(name string) SummaryMetric {
+func (m *testMetricsProvider) NewWorkDurationMetric(name string) HistogramMetric {
 	return &m.duration
 }