make hpa upscale and downscale delay window configurable

pkg/controller/podautoscaler/horizontal.go

@@ -85,6 +85,9 @@ type HorizontalController struct {
 	replicaCalc   *ReplicaCalculator
 	eventRecorder record.EventRecorder
 
+	upscaleForbiddenWindow   time.Duration
+	downscaleForbiddenWindow time.Duration
+
 	// hpaLister is able to list/get HPAs from the shared cache from the informer passed in to
 	// NewHorizontalController.
 	hpaLister       autoscalinglisters.HorizontalPodAutoscalerLister
@@ -94,9 +97,6 @@ type HorizontalController struct {
 	queue workqueue.RateLimitingInterface
 }
 
-var downscaleForbiddenWindow = 5 * time.Minute
-var upscaleForbiddenWindow = 3 * time.Minute
-
 func NewHorizontalController(
 	evtNamespacer v1core.EventsGetter,
 	scaleNamespacer extensionsclient.ScalesGetter,
@@ -104,6 +104,9 @@ func NewHorizontalController(
 	replicaCalc *ReplicaCalculator,
 	hpaInformer autoscalinginformers.HorizontalPodAutoscalerInformer,
 	resyncPeriod time.Duration,
+	upscaleForbiddenWindow time.Duration,
+	downscaleForbiddenWindow time.Duration,
+
 ) *HorizontalController {
 	broadcaster := record.NewBroadcaster()
 	// TODO: remove the wrapper when every clients have moved to use the clientset.
@@ -111,11 +114,13 @@ func NewHorizontalController(
 	recorder := broadcaster.NewRecorder(api.Scheme, clientv1.EventSource{Component: "horizontal-pod-autoscaler"})
 
 	hpaController := &HorizontalController{
-		replicaCalc:     replicaCalc,
-		eventRecorder:   recorder,
-		scaleNamespacer: scaleNamespacer,
-		hpaNamespacer:   hpaNamespacer,
-		queue:           workqueue.NewNamedRateLimitingQueue(NewDefaultHPARateLimiter(resyncPeriod), "horizontalpodautoscaler"),
+		replicaCalc:              replicaCalc,
+		eventRecorder:            recorder,
+		scaleNamespacer:          scaleNamespacer,
+		hpaNamespacer:            hpaNamespacer,
+		upscaleForbiddenWindow:   upscaleForbiddenWindow,
+		downscaleForbiddenWindow: downscaleForbiddenWindow,
+		queue: workqueue.NewNamedRateLimitingQueue(NewDefaultHPARateLimiter(resyncPeriod), "horizontalpodautoscaler"),
 	}
 
 	hpaInformer.Informer().AddEventHandlerWithResyncPeriod(
@@ -434,7 +439,7 @@ func (a *HorizontalController) reconcileAutoscaler(hpav1Shared *autoscalingv1.Ho
 			desiredReplicas = calculateScaleUpLimit(currentReplicas)
 		}
 
-		rescale = shouldScale(hpa, currentReplicas, desiredReplicas, timestamp)
+		rescale = a.shouldScale(hpa, currentReplicas, desiredReplicas, timestamp)
 	}
 
 	if rescale {
@@ -455,7 +460,7 @@ func (a *HorizontalController) reconcileAutoscaler(hpav1Shared *autoscalingv1.Ho
 	return a.updateStatus(hpa, currentReplicas, desiredReplicas, metricStatuses, rescale)
 }
 
-func shouldScale(hpa *autoscalingv2.HorizontalPodAutoscaler, currentReplicas, desiredReplicas int32, timestamp time.Time) bool {
+func (a *HorizontalController) shouldScale(hpa *autoscalingv2.HorizontalPodAutoscaler, currentReplicas, desiredReplicas int32, timestamp time.Time) bool {
 	if desiredReplicas == currentReplicas {
 		return false
 	}
@@ -466,13 +471,13 @@ func shouldScale(hpa *autoscalingv2.HorizontalPodAutoscaler, currentReplicas, de
 
 	// Going down only if the usageRatio dropped significantly below the target
 	// and there was no rescaling in the last downscaleForbiddenWindow.
-	if desiredReplicas < currentReplicas && hpa.Status.LastScaleTime.Add(downscaleForbiddenWindow).Before(timestamp) {
+	if desiredReplicas < currentReplicas && hpa.Status.LastScaleTime.Add(a.downscaleForbiddenWindow).Before(timestamp) {
 		return true
 	}
 
 	// Going up only if the usage ratio increased significantly above the target
 	// and there was no rescaling in the last upscaleForbiddenWindow.
-	if desiredReplicas > currentReplicas && hpa.Status.LastScaleTime.Add(upscaleForbiddenWindow).Before(timestamp) {
+	if desiredReplicas > currentReplicas && hpa.Status.LastScaleTime.Add(a.upscaleForbiddenWindow).Before(timestamp) {
 		return true
 	}
 

pkg/controller/podautoscaler/horizontal_test.go

@@ -518,6 +518,8 @@ func (tc *testCase) runTest(t *testing.T) {
 	}
 
 	informerFactory := informers.NewSharedInformerFactory(testClient, controller.NoResyncPeriodFunc())
+	defaultUpscaleForbiddenWindow := 3 * time.Minute
+	defaultDownscaleForbiddenWindow := 5 * time.Minute
 
 	hpaController := NewHorizontalController(
 		eventClient.Core(),
@@ -526,6 +528,8 @@ func (tc *testCase) runTest(t *testing.T) {
 		replicaCalc,
 		informerFactory.Autoscaling().V1().HorizontalPodAutoscalers(),
 		controller.NoResyncPeriodFunc(),
+		defaultUpscaleForbiddenWindow,
+		defaultDownscaleForbiddenWindow,
 	)
 	hpaController.hpaListerSynced = alwaysReady
 

pkg/controller/podautoscaler/legacy_horizontal_test.go

@@ -489,6 +489,8 @@ func (tc *legacyTestCase) runTest(t *testing.T) {
 	}
 
 	informerFactory := informers.NewSharedInformerFactory(testClient, controller.NoResyncPeriodFunc())
+	defaultUpscaleForbiddenWindow := 3 * time.Minute
+	defaultDownscaleForbiddenWindow := 5 * time.Minute
 
 	hpaController := NewHorizontalController(
 		eventClient.Core(),
@@ -497,6 +499,8 @@ func (tc *legacyTestCase) runTest(t *testing.T) {
 		replicaCalc,
 		informerFactory.Autoscaling().V1().HorizontalPodAutoscalers(),
 		controller.NoResyncPeriodFunc(),
+		defaultUpscaleForbiddenWindow,
+		defaultDownscaleForbiddenWindow,
 	)
 	hpaController.hpaListerSynced = alwaysReady