✨ Adopt native histograms (kubernetes-sigs#3165)

* adopt native histograms

* add native histograms to workqueue metrics too

* adopt native histograms for admission histogram

Author: krisztianfekete

pkg/internal/controller/metrics/metrics.go

@@ -17,6 +17,8 @@ limitations under the License.
 package metrics
 
 import (
+	"time"
+
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/collectors"
 	"sigs.k8s.io/controller-runtime/pkg/metrics"
@@ -60,6 +62,9 @@ var (
 		Help: "Length of time per reconciliation per controller",
 		Buckets: []float64{0.005, 0.01, 0.025, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0,
 			1.25, 1.5, 1.75, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 40, 50, 60},
+		NativeHistogramBucketFactor:     1.1,
+		NativeHistogramMaxBucketNumber:  100,
+		NativeHistogramMinResetDuration: 1 * time.Hour,
 	}, []string{"controller"})
 
 	// WorkerCount is a prometheus metric which holds the number of

pkg/internal/metrics/workqueue.go

@@ -18,6 +18,7 @@ package metrics
 
 import (
 	"strconv"
+	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
 	"k8s.io/client-go/util/workqueue"
@@ -54,17 +55,23 @@ var (
 	}, []string{"name", "controller"})
 
 	latency = prometheus.NewHistogramVec(prometheus.HistogramOpts{
-		Subsystem: WorkQueueSubsystem,
-		Name:      QueueLatencyKey,
-		Help:      "How long in seconds an item stays in workqueue before being requested",
-		Buckets:   prometheus.ExponentialBuckets(10e-9, 10, 12),
+		Subsystem:                       WorkQueueSubsystem,
+		Name:                            QueueLatencyKey,
+		Help:                            "How long in seconds an item stays in workqueue before being requested",
+		Buckets:                         prometheus.ExponentialBuckets(10e-9, 10, 12),
+		NativeHistogramBucketFactor:     1.1,
+		NativeHistogramMaxBucketNumber:  100,
+		NativeHistogramMinResetDuration: 1 * time.Hour,
 	}, []string{"name", "controller"})
 
 	workDuration = prometheus.NewHistogramVec(prometheus.HistogramOpts{
-		Subsystem: WorkQueueSubsystem,
-		Name:      WorkDurationKey,
-		Help:      "How long in seconds processing an item from workqueue takes.",
-		Buckets:   prometheus.ExponentialBuckets(10e-9, 10, 12),
+		Subsystem:                       WorkQueueSubsystem,
+		Name:                            WorkDurationKey,
+		Help:                            "How long in seconds processing an item from workqueue takes.",
+		Buckets:                         prometheus.ExponentialBuckets(10e-9, 10, 12),
+		NativeHistogramBucketFactor:     1.1,
+		NativeHistogramMaxBucketNumber:  100,
+		NativeHistogramMinResetDuration: 1 * time.Hour,
 	}, []string{"name", "controller"})
 
 	unfinished = prometheus.NewGaugeVec(prometheus.GaugeOpts{

pkg/webhook/internal/metrics/metrics.go

@@ -18,6 +18,7 @@ package metrics
 
 import (
 	"net/http"
+	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
@@ -30,8 +31,11 @@ var (
 	// of processing admission requests.
 	RequestLatency = prometheus.NewHistogramVec(
 		prometheus.HistogramOpts{
-			Name: "controller_runtime_webhook_latency_seconds",
-			Help: "Histogram of the latency of processing admission requests",
+			Name:                            "controller_runtime_webhook_latency_seconds",
+			Help:                            "Histogram of the latency of processing admission requests",
+			NativeHistogramBucketFactor:     1.1,
+			NativeHistogramMaxBucketNumber:  100,
+			NativeHistogramMinResetDuration: 1 * time.Hour,
 		},
 		[]string{"webhook"},
 	)