Merge pull request kubernetes#126227 from sanposhiho/queueing_hint_execution_duration_seconds

feature: support queueing_hint_execution_duration_seconds metric

Author: k8s-ci-robot

pkg/scheduler/internal/queue/scheduling_queue.go

@@ -497,6 +497,7 @@ func (p *PriorityQueue) isPodWorthRequeuing(logger klog.Logger, pInfo *framework
 				continue
 			}
 
+			start := time.Now()
 			hint, err := hintfn.QueueingHintFn(logger, pod, oldObj, newObj)
 			if err != nil {
 				// If the QueueingHintFn returned an error, we should treat the event as Queue so that we can prevent
@@ -509,6 +510,8 @@ func (p *PriorityQueue) isPodWorthRequeuing(logger klog.Logger, pInfo *framework
 				}
 				hint = framework.Queue
 			}
+			p.metricsRecorder.ObserveQueueingHintDurationAsync(hintfn.PluginName, event.Label, queueingHintToLabel(hint, err), metrics.SinceInSeconds(start))
+
 			if hint == framework.QueueSkip {
 				continue
 			}
@@ -536,6 +539,23 @@ func (p *PriorityQueue) isPodWorthRequeuing(logger klog.Logger, pInfo *framework
 	return queueStrategy
 }
 
+// queueingHintToLabel converts a hint and an error from QHint to a label string.
+func queueingHintToLabel(hint framework.QueueingHint, err error) string {
+	if err != nil {
+		return metrics.QueueingHintResultError
+	}
+
+	switch hint {
+	case framework.Queue:
+		return metrics.QueueingHintResultQueue
+	case framework.QueueSkip:
+		return metrics.QueueingHintResultQueueSkip
+	}
+
+	// Shouldn't reach here.
+	return ""
+}
+
 // runPreEnqueuePlugins iterates PreEnqueue function in each registered PreEnqueuePlugin.
 // It returns true if all PreEnqueue function run successfully; otherwise returns false
 // upon the first failure.

pkg/scheduler/metrics/metric_recorder.go

@@ -119,9 +119,19 @@ func NewMetricsAsyncRecorder(bufferSize int, interval time.Duration, stopCh <-ch
 // ObservePluginDurationAsync observes the plugin_execution_duration_seconds metric.
 // The metric will be flushed to Prometheus asynchronously.
 func (r *MetricAsyncRecorder) ObservePluginDurationAsync(extensionPoint, pluginName, status string, value float64) {
+	r.observeMetricAsync(PluginExecutionDuration, value, pluginName, extensionPoint, status)
+}
+
+// ObserveQueueingHintDurationAsync observes the queueing_hint_execution_duration_seconds metric.
+// The metric will be flushed to Prometheus asynchronously.
+func (r *MetricAsyncRecorder) ObserveQueueingHintDurationAsync(pluginName, event, hint string, value float64) {
+	r.observeMetricAsync(queueingHintExecutionDuration, value, pluginName, event, hint)
+}
+
+func (r *MetricAsyncRecorder) observeMetricAsync(m *metrics.HistogramVec, value float64, labelsValues ...string) {
 	newMetric := &metric{
-		metric:      PluginExecutionDuration,
-		labelValues: []string{pluginName, extensionPoint, status},
+		metric:      m,
+		labelValues: labelsValues,
 		value:       value,
 	}
 	select {

pkg/scheduler/metrics/metrics.go

@@ -20,8 +20,10 @@ import (
 	"sync"
 	"time"
 
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	"k8s.io/component-base/metrics"
 	"k8s.io/component-base/metrics/legacyregistry"
+	"k8s.io/kubernetes/pkg/features"
 	volumebindingmetrics "k8s.io/kubernetes/pkg/scheduler/framework/plugins/volumebinding/metrics"
 )
 
@@ -73,6 +75,12 @@ const (
 	Permit                      = "Permit"
 )
 
+const (
+	QueueingHintResultQueue     = "Queue"
+	QueueingHintResultQueueSkip = "QueueSkip"
+	QueueingHintResultError     = "Error"
+)
+
 // All the histogram based metrics have 1ms as size for the smallest bucket.
 var (
 	scheduleAttempts = metrics.NewCounterVec(
@@ -198,6 +206,19 @@ var (
 		},
 		[]string{"plugin", "extension_point", "status"})
 
+	// This is only available when the QHint feature gate is enabled.
+	queueingHintExecutionDuration = metrics.NewHistogramVec(
+		&metrics.HistogramOpts{
+			Subsystem: SchedulerSubsystem,
+			Name:      "queueing_hint_execution_duration_seconds",
+			Help:      "Duration for running a queueing hint function of a plugin.",
+			// Start with 0.01ms with the last bucket being [~22ms, Inf). We use a small factor (1.5)
+			// so that we have better granularity since plugin latency is very sensitive.
+			Buckets:        metrics.ExponentialBuckets(0.00001, 1.5, 20),
+			StabilityLevel: metrics.ALPHA,
+		},
+		[]string{"plugin", "event", "hint"})
+
 	SchedulerQueueIncomingPods = metrics.NewCounterVec(
 		&metrics.CounterOpts{
 			Subsystem:      SchedulerSubsystem,
@@ -269,6 +290,9 @@ func Register() {
 	// Register the metrics.
 	registerMetrics.Do(func() {
 		RegisterMetrics(metricsList...)
+		if utilfeature.DefaultFeatureGate.Enabled(features.SchedulerQueueingHints) {
+			RegisterMetrics(queueingHintExecutionDuration)
+		}
 		volumebindingmetrics.RegisterVolumeSchedulingMetrics()
 	})
 }