mgazza · June 2, 2021 09:51 · Jan 15, 2019 · Jan 15, 2019 · Jan 15, 2019
diff --git a/replica_calculator.go b/replica_calculator.go
@@ -0,0 +1,415 @@
+/*
+Copyright 2016 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package podautoscaler
+
+import (
+	"fmt"
+	"math"
+	"time"
+
+	autoscaling "k8s.io/api/autoscaling/v2beta2"
+	"k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/labels"
+	"k8s.io/apimachinery/pkg/util/sets"
+	corelisters "k8s.io/client-go/listers/core/v1"
+	podutil "k8s.io/kubernetes/pkg/api/v1/pod"
+	metricsclient "k8s.io/kubernetes/pkg/controller/podautoscaler/metrics"
+)
+
+const (
+	// defaultTestingTolerance is default value for calculating when to
+	// scale up/scale down.
+	defaultTestingTolerance                     = 0.1
+	defaultTestingCpuInitializationPeriod       = 2 * time.Minute
+	defaultTestingDelayOfInitialReadinessStatus = 10 * time.Second
+)
+
+type ReplicaCalculator struct {
+	metricsClient                 metricsclient.MetricsClient
+	podLister                     corelisters.PodLister
+	tolerance                     float64
+	cpuInitializationPeriod       time.Duration
+	delayOfInitialReadinessStatus time.Duration
+}
+
+func NewReplicaCalculator(metricsClient metricsclient.MetricsClient, podLister corelisters.PodLister, tolerance float64, cpuInitializationPeriod, delayOfInitialReadinessStatus time.Duration) *ReplicaCalculator {
+	return &ReplicaCalculator{
+		metricsClient:                 metricsClient,
+		podLister:                     podLister,
+		tolerance:                     tolerance,
+		cpuInitializationPeriod:       cpuInitializationPeriod,
+		delayOfInitialReadinessStatus: delayOfInitialReadinessStatus,
+	}
+}
+
+// GetResourceReplicas calculates the desired replica count based on a target resource utilization percentage
+// of the given resource for pods matching the given selector in the given namespace, and the current replica count
+func (c *ReplicaCalculator) GetResourceReplicas(currentReplicas int32, targetUtilization int32, resource v1.ResourceName, namespace string, selector labels.Selector) (replicaCount int32, utilization int32, rawUtilization int64, timestamp time.Time, err error) {
+	metrics, timestamp, err := c.metricsClient.GetResourceMetric(resource, namespace, selector)
+	if err != nil {
+		return 0, 0, 0, time.Time{}, fmt.Errorf("unable to get metrics for resource %s: %v", resource, err)
+	}
+	podList, err := c.podLister.Pods(namespace).List(selector)
+	if err != nil {
+		return 0, 0, 0, time.Time{}, fmt.Errorf("unable to get pods while calculating replica count: %v", err)
+	}
+
+	itemsLen := len(podList)
+	if itemsLen == 0 {
+		return 0, 0, 0, time.Time{}, fmt.Errorf("no pods returned by selector while calculating replica count")
+	}
+
+	readyPodCount, ignoredPods, missingPods := groupPods(podList, metrics, resource, c.cpuInitializationPeriod, c.delayOfInitialReadinessStatus)
+	removeMetricsForPods(metrics, ignoredPods)
+	requests, err := calculatePodRequests(podList, resource)
+	if err != nil {
+		return 0, 0, 0, time.Time{}, err
+	}
+
+	if len(metrics) == 0 {
+		return 0, 0, 0, time.Time{}, fmt.Errorf("did not receive metrics for any ready pods")
+	}
+
+	if resource == v1.ResourceMemory {
+		for _,pod := range podList {
+			// any pod that's not ready but running consider it to have 100% resource usage
+
+			_, condition := podutil.GetPodCondition(&pod.Status, v1.PodReady)
+			if condition == nil || pod.Status.StartTime == nil {
+				continue
+			}
+			if condition.Status == v1.ConditionFalse && pod.Status.Phase == v1.PodRunning {
+				metrics[pod.Name] = metricsclient.PodMetric{Value: requests[pod.Name]}
+
+			}
+		}
+	}
+
+	usageRatio, utilization, rawUtilization, err := metricsclient.GetResourceUtilizationRatio(metrics, requests, targetUtilization)
+	if err != nil {
+		return 0, 0, 0, time.Time{}, err
+	}
+
+	rebalanceIgnored := len(ignoredPods) > 0 && usageRatio > 1.0
+	if !rebalanceIgnored && len(missingPods) == 0 {
+		if math.Abs(1.0-usageRatio) <= c.tolerance {
+			// return the current replicas if the change would be too small
+			return currentReplicas, utilization, rawUtilization, timestamp, nil
+		}
+
+		// if we don't have any unready or missing pods, we can calculate the new replica count now
+		return int32(math.Ceil(usageRatio * float64(readyPodCount))), utilization, rawUtilization, timestamp, nil
+	}
+
+	if len(missingPods) > 0 {
+		if usageRatio < 1.0 {
+			// on a scale-down, treat missing pods as using 100% of the resource request
+			for podName := range missingPods {
+				metrics[podName] = metricsclient.PodMetric{Value: requests[podName]}
+			}
+		} else if usageRatio > 1.0 {
+			// on a scale-up, treat missing pods as using 0% of the resource request
+			for podName := range missingPods {
+				metrics[podName] = metricsclient.PodMetric{Value: 0}
+			}
+		}
+	}
+
+	if rebalanceIgnored {
+		// on a scale-up, treat unready pods as using 0% of the resource request
+		for podName := range ignoredPods {
+			metrics[podName] = metricsclient.PodMetric{Value: 0}
+		}
+	}
+
+	// re-run the utilization calculation with our new numbers
+	newUsageRatio, _, _, err := metricsclient.GetResourceUtilizationRatio(metrics, requests, targetUtilization)
+	if err != nil {
+		return 0, utilization, rawUtilization, time.Time{}, err
+	}
+
+	if math.Abs(1.0-newUsageRatio) <= c.tolerance || (usageRatio < 1.0 && newUsageRatio > 1.0) || (usageRatio > 1.0 && newUsageRatio < 1.0) {
+		// return the current replicas if the change would be too small,
+		// or if the new usage ratio would cause a change in scale direction
+		return currentReplicas, utilization, rawUtilization, timestamp, nil
+	}
+
+	// return the result, where the number of replicas considered is
+	// however many replicas factored into our calculation
+	return int32(math.Ceil(newUsageRatio * float64(len(metrics)))), utilization, rawUtilization, timestamp, nil
+}
+
+// GetRawResourceReplicas calculates the desired replica count based on a target resource utilization (as a raw milli-value)
+// for pods matching the given selector in the given namespace, and the current replica count
+func (c *ReplicaCalculator) GetRawResourceReplicas(currentReplicas int32, targetUtilization int64, resource v1.ResourceName, namespace string, selector labels.Selector) (replicaCount int32, utilization int64, timestamp time.Time, err error) {
+	metrics, timestamp, err := c.metricsClient.GetResourceMetric(resource, namespace, selector)
+	if err != nil {
+		return 0, 0, time.Time{}, fmt.Errorf("unable to get metrics for resource %s: %v", resource, err)
+	}
+
+	replicaCount, utilization, err = c.calcPlainMetricReplicas(metrics, currentReplicas, targetUtilization, namespace, selector, resource)
+	return replicaCount, utilization, timestamp, err
+}
+
+// GetMetricReplicas calculates the desired replica count based on a target metric utilization
+// (as a milli-value) for pods matching the given selector in the given namespace, and the
+// current replica count
+func (c *ReplicaCalculator) GetMetricReplicas(currentReplicas int32, targetUtilization int64, metricName string, namespace string, selector labels.Selector, metricSelector labels.Selector) (replicaCount int32, utilization int64, timestamp time.Time, err error) {
+	metrics, timestamp, err := c.metricsClient.GetRawMetric(metricName, namespace, selector, metricSelector)
+	if err != nil {
+		return 0, 0, time.Time{}, fmt.Errorf("unable to get metric %s: %v", metricName, err)
+	}
+
+	replicaCount, utilization, err = c.calcPlainMetricReplicas(metrics, currentReplicas, targetUtilization, namespace, selector, v1.ResourceName(""))
+	return replicaCount, utilization, timestamp, err
+}
+
+// calcPlainMetricReplicas calculates the desired replicas for plain (i.e. non-utilization percentage) metrics.
+func (c *ReplicaCalculator) calcPlainMetricReplicas(metrics metricsclient.PodMetricsInfo, currentReplicas int32, targetUtilization int64, namespace string, selector labels.Selector, resource v1.ResourceName) (replicaCount int32, utilization int64, err error) {
+
+	podList, err := c.podLister.Pods(namespace).List(selector)
+	if err != nil {
+		return 0, 0, fmt.Errorf("unable to get pods while calculating replica count: %v", err)
+	}
+
+	if len(podList) == 0 {
+		return 0, 0, fmt.Errorf("no pods returned by selector while calculating replica count")
+	}
+
+	readyPodCount, ignoredPods, missingPods := groupPods(podList, metrics, resource, c.cpuInitializationPeriod, c.delayOfInitialReadinessStatus)
+	removeMetricsForPods(metrics, ignoredPods)
+
+	if len(metrics) == 0 {
+		return 0, 0, fmt.Errorf("did not receive metrics for any ready pods")
+	}
+
+	usageRatio, utilization := metricsclient.GetMetricUtilizationRatio(metrics, targetUtilization)
+
+	rebalanceIgnored := len(ignoredPods) > 0 && usageRatio > 1.0
+
+	if !rebalanceIgnored && len(missingPods) == 0 {
+		if math.Abs(1.0-usageRatio) <= c.tolerance {
+			// return the current replicas if the change would be too small
+			return currentReplicas, utilization, nil
+		}
+
+		// if we don't have any unready or missing pods, we can calculate the new replica count now
+		return int32(math.Ceil(usageRatio * float64(readyPodCount))), utilization, nil
+	}
+
+	if len(missingPods) > 0 {
+		if usageRatio < 1.0 {
+			// on a scale-down, treat missing pods as using 100% of the resource request
+			for podName := range missingPods {
+				metrics[podName] = metricsclient.PodMetric{Value: targetUtilization}
+			}
+		} else {
+			// on a scale-up, treat missing pods as using 0% of the resource request
+			for podName := range missingPods {
+				metrics[podName] = metricsclient.PodMetric{Value: 0}
+			}
+		}
+	}
+
+	if rebalanceIgnored {
+		// on a scale-up, treat unready pods as using 0% of the resource request
+		for podName := range ignoredPods {
+			metrics[podName] = metricsclient.PodMetric{Value: 0}
+		}
+	}
+
+	// re-run the utilization calculation with our new numbers
+	newUsageRatio, _ := metricsclient.GetMetricUtilizationRatio(metrics, targetUtilization)
+
+	if math.Abs(1.0-newUsageRatio) <= c.tolerance || (usageRatio < 1.0 && newUsageRatio > 1.0) || (usageRatio > 1.0 && newUsageRatio < 1.0) {
+		// return the current replicas if the change would be too small,
+		// or if the new usage ratio would cause a change in scale direction
+		return currentReplicas, utilization, nil
+	}
+
+	// return the result, where the number of replicas considered is
+	// however many replicas factored into our calculation
+	return int32(math.Ceil(newUsageRatio * float64(len(metrics)))), utilization, nil
+}
+
+// GetObjectMetricReplicas calculates the desired replica count based on a target metric utilization (as a milli-value)
+// for the given object in the given namespace, and the current replica count.
+func (c *ReplicaCalculator) GetObjectMetricReplicas(currentReplicas int32, targetUtilization int64, metricName string, namespace string, objectRef *autoscaling.CrossVersionObjectReference, selector labels.Selector, metricSelector labels.Selector) (replicaCount int32, utilization int64, timestamp time.Time, err error) {
+	utilization, timestamp, err = c.metricsClient.GetObjectMetric(metricName, namespace, objectRef, metricSelector)
+	if err != nil {
+		return 0, 0, time.Time{}, fmt.Errorf("unable to get metric %s: %v on %s %s/%s", metricName, objectRef.Kind, namespace, objectRef.Name, err)
+	}
+
+	usageRatio := float64(utilization) / float64(targetUtilization)
+	if math.Abs(1.0-usageRatio) <= c.tolerance {
+		// return the current replicas if the change would be too small
+		return currentReplicas, utilization, timestamp, nil
+	}
+
+	readyPodCount, err := c.getReadyPodsCount(namespace, selector)
+
+	if err != nil {
+		return 0, 0, time.Time{}, fmt.Errorf("unable to calculate ready pods: %s", err)
+	}
+
+	replicaCount = int32(math.Ceil(usageRatio * float64(readyPodCount)))
+
+	return replicaCount, utilization, timestamp, nil
+}
+
+// @TODO(mattjmcnaughton) Many different functions in this module use variations
+// of this function. Make this function generic, so we don't repeat the same
+// logic in multiple places.
+func (c *ReplicaCalculator) getReadyPodsCount(namespace string, selector labels.Selector) (int64, error) {
+	podList, err := c.podLister.Pods(namespace).List(selector)
+	if err != nil {
+		return 0, fmt.Errorf("unable to get pods while calculating replica count: %v", err)
+	}
+
+	if len(podList) == 0 {
+		return 0, fmt.Errorf("no pods returned by selector while calculating replica count")
+	}
+
+	readyPodCount := 0
+
+	for _, pod := range podList {
+		if pod.Status.Phase == v1.PodRunning && podutil.IsPodReady(pod) {
+			readyPodCount++
+		}
+	}
+
+	return int64(readyPodCount), nil
+}
+
+// GetExternalMetricReplicas calculates the desired replica count based on a
+// target metric value (as a milli-value) for the external metric in the given
+// namespace, and the current replica count.
+func (c *ReplicaCalculator) GetExternalMetricReplicas(currentReplicas int32, targetUtilization int64, metricName, namespace string, metricSelector *metav1.LabelSelector, podSelector labels.Selector) (replicaCount int32, utilization int64, timestamp time.Time, err error) {
+	metricLabelSelector, err := metav1.LabelSelectorAsSelector(metricSelector)
+	if err != nil {
+		return 0, 0, time.Time{}, err
+	}
+	metrics, timestamp, err := c.metricsClient.GetExternalMetric(metricName, namespace, metricLabelSelector)
+	if err != nil {
+		return 0, 0, time.Time{}, fmt.Errorf("unable to get external metric %s/%s/%+v: %s", namespace, metricName, metricSelector, err)
+	}
+	utilization = 0
+	for _, val := range metrics {
+		utilization = utilization + val
+	}
+
+	readyPodCount, err := c.getReadyPodsCount(namespace, podSelector)
+
+	if err != nil {
+		return 0, 0, time.Time{}, fmt.Errorf("unable to calculate ready pods: %s", err)
+	}
+
+	usageRatio := float64(utilization) / float64(targetUtilization)
+	if math.Abs(1.0-usageRatio) <= c.tolerance {
+		// return the current replicas if the change would be too small
+		return currentReplicas, utilization, timestamp, nil
+	}
+
+	return int32(math.Ceil(usageRatio * float64(readyPodCount))), utilization, timestamp, nil
+}
+
+// GetExternalPerPodMetricReplicas calculates the desired replica count based on a
+// target metric value per pod (as a milli-value) for the external metric in the
+// given namespace, and the current replica count.
+func (c *ReplicaCalculator) GetExternalPerPodMetricReplicas(currentReplicas int32, targetUtilizationPerPod int64, metricName, namespace string, metricSelector *metav1.LabelSelector) (replicaCount int32, utilization int64, timestamp time.Time, err error) {
+	metricLabelSelector, err := metav1.LabelSelectorAsSelector(metricSelector)
+	if err != nil {
+		return 0, 0, time.Time{}, err
+	}
+	metrics, timestamp, err := c.metricsClient.GetExternalMetric(metricName, namespace, metricLabelSelector)
+	if err != nil {
+		return 0, 0, time.Time{}, fmt.Errorf("unable to get external metric %s/%s/%+v: %s", namespace, metricName, metricSelector, err)
+	}
+	utilization = 0
+	for _, val := range metrics {
+		utilization = utilization + val
+	}
+
+	replicaCount = currentReplicas
+	usageRatio := float64(utilization) / (float64(targetUtilizationPerPod) * float64(replicaCount))
+	if math.Abs(1.0-usageRatio) > c.tolerance {
+		// update number of replicas if the change is large enough
+		replicaCount = int32(math.Ceil(float64(utilization) / float64(targetUtilizationPerPod)))
+	}
+	utilization = int64(math.Ceil(float64(utilization) / float64(currentReplicas)))
+	return replicaCount, utilization, timestamp, nil
+}
+
+func groupPods(pods []*v1.Pod, metrics metricsclient.PodMetricsInfo, resource v1.ResourceName, cpuInitializationPeriod, delayOfInitialReadinessStatus time.Duration) (readyPodCount int, ignoredPods sets.String, missingPods sets.String) {
+	missingPods = sets.NewString()
+	ignoredPods = sets.NewString()
+	for _, pod := range pods {
+		if pod.DeletionTimestamp != nil || pod.Status.Phase == v1.PodFailed {
+			continue
+		}
+		metric, found := metrics[pod.Name]
+		if !found {
+			missingPods.Insert(pod.Name)
+			continue
+		}
+		if resource == v1.ResourceCPU {
+			var ignorePod bool
+			_, condition := podutil.GetPodCondition(&pod.Status, v1.PodReady)
+			if condition == nil || pod.Status.StartTime == nil {
+				ignorePod = true
+			} else {
+				// Pod still within possible initialisation period.
+				if pod.Status.StartTime.Add(cpuInitializationPeriod).After(time.Now()) {
+					// Ignore sample if pod is unready or one window of metric wasn't collected since last state transition.
+					ignorePod = condition.Status == v1.ConditionFalse || metric.Timestamp.Before(condition.LastTransitionTime.Time.Add(metric.Window))
+				} else {
+					// Ignore metric if pod is unready and it has never been ready.
+					ignorePod = condition.Status == v1.ConditionFalse && pod.Status.StartTime.Add(delayOfInitialReadinessStatus).After(condition.LastTransitionTime.Time)
+				}
+			}
+			if ignorePod {
+				ignoredPods.Insert(pod.Name)
+				continue
+			}
+		}
+		readyPodCount++
+	}
+	return
+}
+
+func calculatePodRequests(pods []*v1.Pod, resource v1.ResourceName) (map[string]int64, error) {
+	requests := make(map[string]int64, len(pods))
+	for _, pod := range pods {
+		podSum := int64(0)
+		for _, container := range pod.Spec.Containers {
+			if containerRequest, ok := container.Resources.Requests[resource]; ok {
+				podSum += containerRequest.MilliValue()
+			} else {
+				return nil, fmt.Errorf("missing request for %s", resource)
+			}
+		}
+		requests[pod.Name] = podSum
+	}
+	return requests, nil
+}
+
+func removeMetricsForPods(metrics metricsclient.PodMetricsInfo, pods sets.String) {
+	for _, pod := range pods.UnsortedList() {
+		delete(metrics, pod)
+	}
+}
diff --git a/horizontal_test.go b/horizontal_test.go
@@ -96,20 +96,20 @@ type testCase struct {
 	initialReplicas int32
 
 	// Memory target utilization as a percentage of the requested resources.
-	MemoryTarget                 int32
-	reportedMemoryLevels         []uint64
-	reportedMemoryRequests       []resource.Quantity
-	reportedPodReadiness         []v1.ConditionStatus
-	reportedPodStartTime         []metav1.Time
-	reportedPodPhase             []v1.PodPhase
-	reportedPodDeletionTimestamp []bool
-	reportedPodMemoryRequests    []resource.Quantity
-	scaleUpdated                 bool
-	statusUpdated                bool
-	eventCreated                 bool
-	verifyEvents                 bool
-	useMetricsAPI                bool
-	metricsTarget                []autoscalingv2.MetricSpec
+	MemoryTargetUtilisationPercent int32
+	reportedMemoryPercentageLevels []uint64
+	reportedMemoryRequests         []resource.Quantity
+	reportedPodReadiness           []v1.ConditionStatus
+	reportedPodStartTime           []metav1.Time
+	reportedPodPhase               []v1.PodPhase
+	reportedPodDeletionTimestamp   []bool
+	reportedPodMemoryRequests      []resource.Quantity
+	scaleUpdated                   bool
+	statusUpdated                  bool
+	eventCreated                   bool
+	verifyEvents                   bool
+	useMetricsAPI                  bool
+	metricsTarget                  []autoscalingv2.MetricSpec
 	expectedDesiredReplicas      int32
 	expectedConditions           []autoscalingv1.HorizontalPodAutoscalerCondition
 	// Channel with names of HPA objects which we have reconciled.
@@ -190,14 +190,14 @@ func (tc *testCase) prepareTestClient(t *testing.T) (*fake.Clientset, *metricsfa
 			},
 		}
 
-		if tc.MemoryTarget > 0 {
+		if tc.MemoryTargetUtilisationPercent > 0 {
 			obj.Items[0].Spec.Metrics = []autoscalingv2.MetricSpec{
 				{
 					Type: autoscalingv2.ResourceMetricSourceType,
 					Resource: &autoscalingv2.ResourceMetricSource{
 						Name: v1.ResourceMemory,
 						Target: autoscalingv2.MetricTarget{
-							AverageUtilization: &tc.MemoryTarget,
+							AverageUtilization: &tc.MemoryTargetUtilisationPercent,
 						},
 					},
 				},
@@ -446,7 +446,7 @@ func (tc *testCase) prepareTestClient(t *testing.T) (*fake.Clientset, *metricsfa
 		defer tc.Unlock()
 
 		metrics := &metricsapi.PodMetricsList{}
-		for i, memMiB := range tc.reportedMemoryLevels {
+		for i, memMiB := range tc.reportedMemoryPercentageLevels {
 			// NB: the list reactor actually does label selector filtering for us,
 			// so we have to make sure our results match the label selector
 			podMetric := metricsapi.PodMetrics{
@@ -494,7 +494,7 @@ func (tc *testCase) prepareTestClient(t *testing.T) (*fake.Clientset, *metricsfa
 			assert.Equal(t, "pods", getForAction.GetResource().Resource, "the type of object that we requested multiple metrics for should have been pods")
 			assert.Equal(t, "qps", getForAction.GetMetricName(), "the metric name requested should have been qps, as specified in the metric spec")
 
-			for i, level := range tc.reportedMemoryLevels {
+			for i, level := range tc.reportedMemoryPercentageLevels {
 				podMetric := cmapi.MetricValue{
 					DescribedObject: v1.ObjectReference{
 						Kind:      "Pod",
@@ -546,7 +546,7 @@ func (tc *testCase) prepareTestClient(t *testing.T) (*fake.Clientset, *metricsfa
 				Metric: cmapi.MetricIdentifier{
 					Name: "qps",
 				},
-				Value: *resource.NewMilliQuantity(int64(tc.reportedMemoryLevels[0]), resource.DecimalSI),
+				Value: *resource.NewMilliQuantity(int64(tc.reportedMemoryPercentageLevels[0]), resource.DecimalSI),
 			},
 		}
 
@@ -568,7 +568,7 @@ func (tc *testCase) prepareTestClient(t *testing.T) (*fake.Clientset, *metricsfa
 
 		assert.Equal(t, "qps", listAction.GetResource().Resource, "the metric name requested should have been qps, as specified in the metric spec")
 
-		for _, level := range tc.reportedMemoryLevels {
+		for _, level := range tc.reportedMemoryPercentageLevels {
 			metric := emapi.ExternalMetricValue{
 				Timestamp:  metav1.Time{Time: time.Now()},
 				MetricName: "qps",
@@ -631,7 +631,7 @@ func (tc *testCase) setupController(t *testing.T) (*HorizontalController, inform
 				assert.Equal(t, fmt.Sprintf(
 					"Computed the desired num of replicas: %d (avgMemoryutil: %d, current replicas: %d)",
 					tc.expectedDesiredReplicas,
-					(int64(tc.reportedMemoryLevels[0])*100)/tc.reportedMemoryRequests[0].MilliValue(), tc.initialReplicas), obj.Message)
+					(int64(tc.reportedMemoryPercentageLevels[0])*100)/tc.reportedMemoryRequests[0].MilliValue(), tc.initialReplicas), obj.Message)
 			default:
 				assert.False(t, true, fmt.Sprintf("Unexpected event: %s / %s", obj.Reason, obj.Message))
 			}
@@ -699,15 +699,15 @@ func (tc *testCase) runTest(t *testing.T) {
 
 func TestScaleUpUnreadyMoreScale(t *testing.T) {
 	tc := testCase{
-		minReplicas:             2,
-		maxReplicas:             6,
-		initialReplicas:         3,
-		expectedDesiredReplicas: 4,
-		MemoryTarget:            300,
-		reportedMemoryLevels:    []uint64{300, 300, 300},
-		reportedMemoryRequests:  []resource.Quantity{resource.MustParse("300Mi"), resource.MustParse("300Mi"), resource.MustParse("300Mi")},
-		reportedPodReadiness:    []v1.ConditionStatus{v1.ConditionFalse, v1.ConditionFalse, v1.ConditionFalse},
-		useMetricsAPI:           true,
+		minReplicas:                    2,
+		maxReplicas:                    6,
+		initialReplicas:                3,
+		expectedDesiredReplicas:        4,
+		MemoryTargetUtilisationPercent: 90,
+		reportedMemoryPercentageLevels: []uint64{95, 95, 95},
+		reportedMemoryRequests:         []resource.Quantity{resource.MustParse("100Mi"), resource.MustParse("100Mi"), resource.MustParse("100Mi")},
+		reportedPodReadiness:           []v1.ConditionStatus{v1.ConditionFalse, v1.ConditionFalse, v1.ConditionFalse},
+		useMetricsAPI:                  true,
 	}
 	tc.runTest(t)
 }
diff --git a/horizontal_test.go b/horizontal_test.go
@@ -0,0 +1,713 @@
+/*
+Copyright 2015 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package podautoscaler
+
+import (
+	"encoding/json"
+	"fmt"
+	"sync"
+	"testing"
+	"time"
+
+	autoscalingv1 "k8s.io/api/autoscaling/v1"
+	autoscalingv2 "k8s.io/api/autoscaling/v2beta2"
+	"k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/meta/testrestmapper"
+	"k8s.io/apimachinery/pkg/api/resource"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/labels"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/apimachinery/pkg/watch"
+	"k8s.io/client-go/informers"
+	"k8s.io/client-go/kubernetes/fake"
+	scalefake "k8s.io/client-go/scale/fake"
+	core "k8s.io/client-go/testing"
+	"k8s.io/kubernetes/pkg/api/legacyscheme"
+	"k8s.io/kubernetes/pkg/apis/autoscaling"
+	"k8s.io/kubernetes/pkg/controller"
+	"k8s.io/kubernetes/pkg/controller/podautoscaler/metrics"
+	cmapi "k8s.io/metrics/pkg/apis/custom_metrics/v1beta2"
+	emapi "k8s.io/metrics/pkg/apis/external_metrics/v1beta1"
+	metricsapi "k8s.io/metrics/pkg/apis/metrics/v1beta1"
+	metricsfake "k8s.io/metrics/pkg/client/clientset/versioned/fake"
+	cmfake "k8s.io/metrics/pkg/client/custom_metrics/fake"
+	emfake "k8s.io/metrics/pkg/client/external_metrics/fake"
+
+	"github.com/stretchr/testify/assert"
+
+	_ "k8s.io/kubernetes/pkg/apis/apps/install"
+	_ "k8s.io/kubernetes/pkg/apis/autoscaling/install"
+)
+
+var statusOk = []autoscalingv2.HorizontalPodAutoscalerCondition{
+	{Type: autoscalingv2.AbleToScale, Status: v1.ConditionTrue, Reason: "SucceededRescale"},
+	{Type: autoscalingv2.ScalingActive, Status: v1.ConditionTrue, Reason: "ValidMetricFound"},
+	{Type: autoscalingv2.ScalingLimited, Status: v1.ConditionFalse, Reason: "DesiredWithinRange"},
+}
+
+// statusOkWithOverrides returns the "ok" status with the given conditions as overridden
+func statusOkWithOverrides(overrides ...autoscalingv2.HorizontalPodAutoscalerCondition) []autoscalingv1.HorizontalPodAutoscalerCondition {
+	resv2 := make([]autoscalingv2.HorizontalPodAutoscalerCondition, len(statusOk))
+	copy(resv2, statusOk)
+	for _, override := range overrides {
+		resv2 = setConditionInList(resv2, override.Type, override.Status, override.Reason, override.Message)
+	}
+
+	// copy to a v1 slice
+	resv1 := make([]autoscalingv1.HorizontalPodAutoscalerCondition, len(resv2))
+	for i, cond := range resv2 {
+		resv1[i] = autoscalingv1.HorizontalPodAutoscalerCondition{
+			Type:   autoscalingv1.HorizontalPodAutoscalerConditionType(cond.Type),
+			Status: cond.Status,
+			Reason: cond.Reason,
+		}
+	}
+
+	return resv1
+}
+
+func alwaysReady() bool { return true }
+
+type fakeResource struct {
+	name       string
+	apiVersion string
+	kind       string
+}
+
+type testCase struct {
+	sync.Mutex
+	minReplicas     int32
+	maxReplicas     int32
+	initialReplicas int32
+
+	// Memory target utilization as a percentage of the requested resources.
+	MemoryTarget                 int32
+	reportedMemoryLevels         []uint64
+	reportedMemoryRequests       []resource.Quantity
+	reportedPodReadiness         []v1.ConditionStatus
+	reportedPodStartTime         []metav1.Time
+	reportedPodPhase             []v1.PodPhase
+	reportedPodDeletionTimestamp []bool
+	reportedPodMemoryRequests    []resource.Quantity
+	scaleUpdated                 bool
+	statusUpdated                bool
+	eventCreated                 bool
+	verifyEvents                 bool
+	useMetricsAPI                bool
+	metricsTarget                []autoscalingv2.MetricSpec
+	expectedDesiredReplicas      int32
+	expectedConditions           []autoscalingv1.HorizontalPodAutoscalerCondition
+	// Channel with names of HPA objects which we have reconciled.
+	processed chan string
+
+	// Target resource information.
+	resource *fakeResource
+
+	// Last scale time
+	lastScaleTime *metav1.Time
+
+	// override the test clients
+	testClient        *fake.Clientset
+	testMetricsClient *metricsfake.Clientset
+	testCMClient      *cmfake.FakeCustomMetricsClient
+	testEMClient      *emfake.FakeExternalMetricsClient
+	testScaleClient   *scalefake.FakeScaleClient
+
+	recommendations []timestampedRecommendation
+}
+
+func init() {
+	// set this high so we don't accidentally run into it when testing
+	scaleUpLimitFactor = 8
+}
+
+func (tc *testCase) prepareTestClient(t *testing.T) (*fake.Clientset, *metricsfake.Clientset, *cmfake.FakeCustomMetricsClient, *emfake.FakeExternalMetricsClient, *scalefake.FakeScaleClient) {
+	namespace := "test-namespace"
+	hpaName := "test-hpa"
+	podNamePrefix := "test-pod"
+	labelSet := map[string]string{"name": podNamePrefix}
+	selector := labels.SelectorFromSet(labelSet).String()
+
+	tc.Lock()
+
+	tc.scaleUpdated = false
+	tc.statusUpdated = false
+	tc.eventCreated = false
+	tc.processed = make(chan string, 100)
+
+	if tc.resource == nil {
+		tc.resource = &fakeResource{
+			name:       "test-rc",
+			apiVersion: "v1",
+			kind:       "ReplicationController",
+		}
+	}
+	tc.Unlock()
+
+	fakeClient := &fake.Clientset{}
+	fakeClient.AddReactor("list", "horizontalpodautoscalers", func(action core.Action) (handled bool, ret runtime.Object, err error) {
+		tc.Lock()
+		defer tc.Unlock()
+
+		obj := &autoscalingv2.HorizontalPodAutoscalerList{
+			Items: []autoscalingv2.HorizontalPodAutoscaler{
+				{
+					ObjectMeta: metav1.ObjectMeta{
+						Name:      hpaName,
+						Namespace: namespace,
+						SelfLink:  "experimental/v1/namespaces/" + namespace + "/horizontalpodautoscalers/" + hpaName,
+					},
+					Spec: autoscalingv2.HorizontalPodAutoscalerSpec{
+						ScaleTargetRef: autoscalingv2.CrossVersionObjectReference{
+							Kind:       tc.resource.kind,
+							Name:       tc.resource.name,
+							APIVersion: tc.resource.apiVersion,
+						},
+						MinReplicas: &tc.minReplicas,
+						MaxReplicas: tc.maxReplicas,
+					},
+					Status: autoscalingv2.HorizontalPodAutoscalerStatus{
+						CurrentReplicas: tc.initialReplicas,
+						DesiredReplicas: tc.initialReplicas,
+						LastScaleTime:   tc.lastScaleTime,
+					},
+				},
+			},
+		}
+
+		if tc.MemoryTarget > 0 {
+			obj.Items[0].Spec.Metrics = []autoscalingv2.MetricSpec{
+				{
+					Type: autoscalingv2.ResourceMetricSourceType,
+					Resource: &autoscalingv2.ResourceMetricSource{
+						Name: v1.ResourceMemory,
+						Target: autoscalingv2.MetricTarget{
+							AverageUtilization: &tc.MemoryTarget,
+						},
+					},
+				},
+			}
+		}
+		if len(tc.metricsTarget) > 0 {
+			obj.Items[0].Spec.Metrics = append(obj.Items[0].Spec.Metrics, tc.metricsTarget...)
+		}
+
+		if len(obj.Items[0].Spec.Metrics) == 0 {
+			// manually add in the defaulting logic
+			obj.Items[0].Spec.Metrics = []autoscalingv2.MetricSpec{
+				{
+					Type: autoscalingv2.ResourceMetricSourceType,
+					Resource: &autoscalingv2.ResourceMetricSource{
+						Name: v1.ResourceMemory,
+					},
+				},
+			}
+		}
+
+		// and... convert to autoscaling v1 to return the right type
+		objv1, err := unsafeConvertToVersionVia(obj, autoscalingv1.SchemeGroupVersion)
+		if err != nil {
+			return true, nil, err
+		}
+
+		return true, objv1, nil
+	})
+
+	fakeClient.AddReactor("list", "pods", func(action core.Action) (handled bool, ret runtime.Object, err error) {
+		tc.Lock()
+		defer tc.Unlock()
+
+		obj := &v1.PodList{}
+
+		specifiedMemoryRequests := tc.reportedMemoryRequests != nil
+
+		numPodsToCreate := int(tc.initialReplicas)
+		if specifiedMemoryRequests {
+			numPodsToCreate = len(tc.reportedMemoryRequests)
+		}
+
+		for i := 0; i < numPodsToCreate; i++ {
+			podReadiness := v1.ConditionTrue
+			if tc.reportedPodReadiness != nil {
+				podReadiness = tc.reportedPodReadiness[i]
+			}
+			var podStartTime metav1.Time
+			if tc.reportedPodStartTime != nil {
+				podStartTime = tc.reportedPodStartTime[i]
+			}
+
+			podPhase := v1.PodRunning
+			if tc.reportedPodPhase != nil {
+				podPhase = tc.reportedPodPhase[i]
+			}
+
+			podDeletionTimestamp := false
+			if tc.reportedPodDeletionTimestamp != nil {
+				podDeletionTimestamp = tc.reportedPodDeletionTimestamp[i]
+			}
+
+			podName := fmt.Sprintf("%s-%d", podNamePrefix, i)
+
+			reportedMemoryRequest := resource.MustParse("100Mi")
+			if specifiedMemoryRequests {
+				reportedMemoryRequest = tc.reportedMemoryRequests[i]
+			}
+
+			pod := v1.Pod{
+				Status: v1.PodStatus{
+					Phase: podPhase,
+					Conditions: []v1.PodCondition{
+						{
+							Type:               v1.PodReady,
+							Status:             podReadiness,
+							LastTransitionTime: podStartTime,
+						},
+					},
+					StartTime: &podStartTime,
+				},
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      podName,
+					Namespace: namespace,
+					Labels: map[string]string{
+						"name": podNamePrefix,
+					},
+				},
+
+				Spec: v1.PodSpec{
+					Containers: []v1.Container{
+						{
+							Resources: v1.ResourceRequirements{
+								Requests: v1.ResourceList{
+									v1.ResourceMemory: reportedMemoryRequest,
+								},
+							},
+						},
+					},
+				},
+			}
+			if podDeletionTimestamp {
+				pod.DeletionTimestamp = &metav1.Time{Time: time.Now()}
+			}
+			obj.Items = append(obj.Items, pod)
+		}
+		return true, obj, nil
+	})
+
+	fakeClient.AddReactor("update", "horizontalpodautoscalers", func(action core.Action) (handled bool, ret runtime.Object, err error) {
+		tc.Lock()
+		defer tc.Unlock()
+
+		obj := action.(core.UpdateAction).GetObject().(*autoscalingv1.HorizontalPodAutoscaler)
+		assert.Equal(t, namespace, obj.Namespace, "the HPA namespace should be as expected")
+		assert.Equal(t, hpaName, obj.Name, "the HPA name should be as expected")
+		assert.Equal(t, tc.expectedDesiredReplicas, obj.Status.DesiredReplicas, "the desired replica count reported in the object status should be as expected")
+		/*if tc.verifyMemoryCurrent {
+			if assert.NotNil(t, obj.Status.CurrentMemoryUtilizationPercentage, "the reported Memory utilization percentage should be non-nil") {
+				assert.Equal(t, tc.MemoryCurrent, *obj.Status.CurrentMemoryUtilizationPercentage, "the report Memory utilization percentage should be as expected")
+			}
+		}*/
+		var actualConditions []autoscalingv1.HorizontalPodAutoscalerCondition
+		if err := json.Unmarshal([]byte(obj.ObjectMeta.Annotations[autoscaling.HorizontalPodAutoscalerConditionsAnnotation]), &actualConditions); err != nil {
+			return true, nil, err
+		}
+		// TODO: it's ok not to sort these becaues statusOk
+		// contains all the conditions, so we'll never be appending.
+		// Default to statusOk when missing any specific conditions
+		if tc.expectedConditions == nil {
+			tc.expectedConditions = statusOkWithOverrides()
+		}
+		// clear the message so that we can easily compare
+		for i := range actualConditions {
+			actualConditions[i].Message = ""
+			actualConditions[i].LastTransitionTime = metav1.Time{}
+		}
+		assert.Equal(t, tc.expectedConditions, actualConditions, "the status conditions should have been as expected")
+		tc.statusUpdated = true
+		// Every time we reconcile HPA object we are updating status.
+		tc.processed <- obj.Name
+		return true, obj, nil
+	})
+
+	fakeScaleClient := &scalefake.FakeScaleClient{}
+	fakeScaleClient.AddReactor("get", "replicationcontrollers", func(action core.Action) (handled bool, ret runtime.Object, err error) {
+		tc.Lock()
+		defer tc.Unlock()
+
+		obj := &autoscalingv1.Scale{
+			ObjectMeta: metav1.ObjectMeta{
+				Name:      tc.resource.name,
+				Namespace: namespace,
+			},
+			Spec: autoscalingv1.ScaleSpec{
+				Replicas: tc.initialReplicas,
+			},
+			Status: autoscalingv1.ScaleStatus{
+				Replicas: tc.initialReplicas,
+				Selector: selector,
+			},
+		}
+		return true, obj, nil
+	})
+
+	fakeScaleClient.AddReactor("get", "deployments", func(action core.Action) (handled bool, ret runtime.Object, err error) {
+		tc.Lock()
+		defer tc.Unlock()
+
+		obj := &autoscalingv1.Scale{
+			ObjectMeta: metav1.ObjectMeta{
+				Name:      tc.resource.name,
+				Namespace: namespace,
+			},
+			Spec: autoscalingv1.ScaleSpec{
+				Replicas: tc.initialReplicas,
+			},
+			Status: autoscalingv1.ScaleStatus{
+				Replicas: tc.initialReplicas,
+				Selector: selector,
+			},
+		}
+		return true, obj, nil
+	})
+
+	fakeScaleClient.AddReactor("get", "replicasets", func(action core.Action) (handled bool, ret runtime.Object, err error) {
+		tc.Lock()
+		defer tc.Unlock()
+
+		obj := &autoscalingv1.Scale{
+			ObjectMeta: metav1.ObjectMeta{
+				Name:      tc.resource.name,
+				Namespace: namespace,
+			},
+			Spec: autoscalingv1.ScaleSpec{
+				Replicas: tc.initialReplicas,
+			},
+			Status: autoscalingv1.ScaleStatus{
+				Replicas: tc.initialReplicas,
+				Selector: selector,
+			},
+		}
+		return true, obj, nil
+	})
+
+	fakeScaleClient.AddReactor("update", "replicationcontrollers", func(action core.Action) (handled bool, ret runtime.Object, err error) {
+		tc.Lock()
+		defer tc.Unlock()
+
+		obj := action.(core.UpdateAction).GetObject().(*autoscalingv1.Scale)
+		replicas := action.(core.UpdateAction).GetObject().(*autoscalingv1.Scale).Spec.Replicas
+		assert.Equal(t, tc.expectedDesiredReplicas, replicas, "the replica count of the RC should be as expected")
+		tc.scaleUpdated = true
+		return true, obj, nil
+	})
+
+	fakeScaleClient.AddReactor("update", "deployments", func(action core.Action) (handled bool, ret runtime.Object, err error) {
+		tc.Lock()
+		defer tc.Unlock()
+
+		obj := action.(core.UpdateAction).GetObject().(*autoscalingv1.Scale)
+		replicas := action.(core.UpdateAction).GetObject().(*autoscalingv1.Scale).Spec.Replicas
+		assert.Equal(t, tc.expectedDesiredReplicas, replicas, "the replica count of the deployment should be as expected")
+		tc.scaleUpdated = true
+		return true, obj, nil
+	})
+
+	fakeScaleClient.AddReactor("update", "replicasets", func(action core.Action) (handled bool, ret runtime.Object, err error) {
+		tc.Lock()
+		defer tc.Unlock()
+
+		obj := action.(core.UpdateAction).GetObject().(*autoscalingv1.Scale)
+		replicas := action.(core.UpdateAction).GetObject().(*autoscalingv1.Scale).Spec.Replicas
+		assert.Equal(t, tc.expectedDesiredReplicas, replicas, "the replica count of the replicaset should be as expected")
+		tc.scaleUpdated = true
+		return true, obj, nil
+	})
+
+	fakeWatch := watch.NewFake()
+	fakeClient.AddWatchReactor("*", core.DefaultWatchReactor(fakeWatch, nil))
+
+	fakeMetricsClient := &metricsfake.Clientset{}
+	fakeMetricsClient.AddReactor("list", "pods", func(action core.Action) (handled bool, ret runtime.Object, err error) {
+		tc.Lock()
+		defer tc.Unlock()
+
+		metrics := &metricsapi.PodMetricsList{}
+		for i, memMiB := range tc.reportedMemoryLevels {
+			// NB: the list reactor actually does label selector filtering for us,
+			// so we have to make sure our results match the label selector
+			podMetric := metricsapi.PodMetrics{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      fmt.Sprintf("%s-%d", podNamePrefix, i),
+					Namespace: namespace,
+					Labels:    labelSet,
+				},
+				Timestamp: metav1.Time{Time: time.Now()},
+				Window:    metav1.Duration{Duration: time.Minute},
+				Containers: []metricsapi.ContainerMetrics{
+					{
+						Name: "container",
+						Usage: v1.ResourceList{
+							v1.ResourceCPU: *resource.NewMilliQuantity(
+								int64(0),
+								resource.DecimalSI),
+							v1.ResourceMemory: *resource.NewQuantity(
+								int64(memMiB*1024*1024),
+								resource.BinarySI),
+						},
+					},
+				},
+			}
+			metrics.Items = append(metrics.Items, podMetric)
+		}
+
+		return true, metrics, nil
+	})
+
+	fakeCMClient := &cmfake.FakeCustomMetricsClient{}
+	fakeCMClient.AddReactor("get", "*", func(action core.Action) (handled bool, ret runtime.Object, err error) {
+		tc.Lock()
+		defer tc.Unlock()
+
+		getForAction, wasGetFor := action.(cmfake.GetForAction)
+		if !wasGetFor {
+			return true, nil, fmt.Errorf("expected a get-for action, got %v instead", action)
+		}
+
+		if getForAction.GetName() == "*" {
+			metrics := &cmapi.MetricValueList{}
+
+			// multiple objects
+			assert.Equal(t, "pods", getForAction.GetResource().Resource, "the type of object that we requested multiple metrics for should have been pods")
+			assert.Equal(t, "qps", getForAction.GetMetricName(), "the metric name requested should have been qps, as specified in the metric spec")
+
+			for i, level := range tc.reportedMemoryLevels {
+				podMetric := cmapi.MetricValue{
+					DescribedObject: v1.ObjectReference{
+						Kind:      "Pod",
+						Name:      fmt.Sprintf("%s-%d", podNamePrefix, i),
+						Namespace: namespace,
+					},
+					Timestamp: metav1.Time{Time: time.Now()},
+					Metric: cmapi.MetricIdentifier{
+						Name: "qps",
+					},
+					Value: *resource.NewMilliQuantity(int64(level), resource.DecimalSI),
+				}
+				metrics.Items = append(metrics.Items, podMetric)
+			}
+
+			return true, metrics, nil
+		}
+
+		name := getForAction.GetName()
+		mapper := testrestmapper.TestOnlyStaticRESTMapper(legacyscheme.Scheme)
+		metrics := &cmapi.MetricValueList{}
+		var matchedTarget *autoscalingv2.MetricSpec
+		for i, target := range tc.metricsTarget {
+			if target.Type == autoscalingv2.ObjectMetricSourceType && name == target.Object.DescribedObject.Name {
+				gk := schema.FromAPIVersionAndKind(target.Object.DescribedObject.APIVersion, target.Object.DescribedObject.Kind).GroupKind()
+				mapping, err := mapper.RESTMapping(gk)
+				if err != nil {
+					t.Logf("unable to get mapping for %s: %v", gk.String(), err)
+					continue
+				}
+				groupResource := mapping.Resource.GroupResource()
+
+				if getForAction.GetResource().Resource == groupResource.String() {
+					matchedTarget = &tc.metricsTarget[i]
+				}
+			}
+		}
+		assert.NotNil(t, matchedTarget, "this request should have matched one of the metric specs")
+		assert.Equal(t, "qps", getForAction.GetMetricName(), "the metric name requested should have been qps, as specified in the metric spec")
+
+		metrics.Items = []cmapi.MetricValue{
+			{
+				DescribedObject: v1.ObjectReference{
+					Kind:       matchedTarget.Object.DescribedObject.Kind,
+					APIVersion: matchedTarget.Object.DescribedObject.APIVersion,
+					Name:       name,
+				},
+				Timestamp: metav1.Time{Time: time.Now()},
+				Metric: cmapi.MetricIdentifier{
+					Name: "qps",
+				},
+				Value: *resource.NewMilliQuantity(int64(tc.reportedMemoryLevels[0]), resource.DecimalSI),
+			},
+		}
+
+		return true, metrics, nil
+	})
+
+	fakeEMClient := &emfake.FakeExternalMetricsClient{}
+
+	fakeEMClient.AddReactor("list", "*", func(action core.Action) (handled bool, ret runtime.Object, err error) {
+		tc.Lock()
+		defer tc.Unlock()
+
+		listAction, wasList := action.(core.ListAction)
+		if !wasList {
+			return true, nil, fmt.Errorf("expected a list action, got %v instead", action)
+		}
+
+		metrics := &emapi.ExternalMetricValueList{}
+
+		assert.Equal(t, "qps", listAction.GetResource().Resource, "the metric name requested should have been qps, as specified in the metric spec")
+
+		for _, level := range tc.reportedMemoryLevels {
+			metric := emapi.ExternalMetricValue{
+				Timestamp:  metav1.Time{Time: time.Now()},
+				MetricName: "qps",
+				Value:      *resource.NewMilliQuantity(int64(level), resource.DecimalSI),
+			}
+			metrics.Items = append(metrics.Items, metric)
+		}
+
+		return true, metrics, nil
+	})
+
+	return fakeClient, fakeMetricsClient, fakeCMClient, fakeEMClient, fakeScaleClient
+}
+
+func (tc *testCase) verifyResults(t *testing.T) {
+	tc.Lock()
+	defer tc.Unlock()
+
+	assert.Equal(t, tc.initialReplicas != tc.expectedDesiredReplicas, tc.scaleUpdated, "the scale should only be updated if we expected a change in replicas")
+	assert.True(t, tc.statusUpdated, "the status should have been updated")
+	if tc.verifyEvents {
+		assert.Equal(t, tc.initialReplicas != tc.expectedDesiredReplicas, tc.eventCreated, "an event should have been created only if we expected a change in replicas")
+	}
+}
+
+func (tc *testCase) setupController(t *testing.T) (*HorizontalController, informers.SharedInformerFactory) {
+	testClient, testMetricsClient, testCMClient, testEMClient, testScaleClient := tc.prepareTestClient(t)
+	if tc.testClient != nil {
+		testClient = tc.testClient
+	}
+	if tc.testMetricsClient != nil {
+		testMetricsClient = tc.testMetricsClient
+	}
+	if tc.testCMClient != nil {
+		testCMClient = tc.testCMClient
+	}
+	if tc.testEMClient != nil {
+		testEMClient = tc.testEMClient
+	}
+	if tc.testScaleClient != nil {
+		testScaleClient = tc.testScaleClient
+	}
+	metricsClient := metrics.NewRESTMetricsClient(
+		testMetricsClient.MetricsV1beta1(),
+		testCMClient,
+		testEMClient,
+	)
+
+	eventClient := &fake.Clientset{}
+	eventClient.AddReactor("create", "events", func(action core.Action) (handled bool, ret runtime.Object, err error) {
+		tc.Lock()
+		defer tc.Unlock()
+
+		obj := action.(core.CreateAction).GetObject().(*v1.Event)
+		if tc.verifyEvents {
+			switch obj.Reason {
+			case "SuccessfulRescale":
+				assert.Equal(t, fmt.Sprintf("New size: %d; reason: cpu resource utilization (percentage of request) above target", tc.expectedDesiredReplicas), obj.Message)
+			case "DesiredReplicasComputed":
+				assert.Equal(t, fmt.Sprintf(
+					"Computed the desired num of replicas: %d (avgMemoryutil: %d, current replicas: %d)",
+					tc.expectedDesiredReplicas,
+					(int64(tc.reportedMemoryLevels[0])*100)/tc.reportedMemoryRequests[0].MilliValue(), tc.initialReplicas), obj.Message)
+			default:
+				assert.False(t, true, fmt.Sprintf("Unexpected event: %s / %s", obj.Reason, obj.Message))
+			}
+		}
+		tc.eventCreated = true
+		return true, obj, nil
+	})
+
+	informerFactory := informers.NewSharedInformerFactory(testClient, controller.NoResyncPeriodFunc())
+	defaultDownscalestabilizationWindow := 5 * time.Minute
+
+	hpaController := NewHorizontalController(
+		eventClient.Core(),
+		testScaleClient,
+		testClient.Autoscaling(),
+		testrestmapper.TestOnlyStaticRESTMapper(legacyscheme.Scheme),
+		metricsClient,
+		informerFactory.Autoscaling().V1().HorizontalPodAutoscalers(),
+		informerFactory.Core().V1().Pods(),
+		controller.NoResyncPeriodFunc(),
+		defaultDownscalestabilizationWindow,
+		defaultTestingTolerance,
+		defaultTestingCpuInitializationPeriod,
+		defaultTestingDelayOfInitialReadinessStatus,
+	)
+	hpaController.hpaListerSynced = alwaysReady
+	if tc.recommendations != nil {
+		hpaController.recommendations["test-namespace/test-hpa"] = tc.recommendations
+	}
+
+	return hpaController, informerFactory
+}
+
+func hotCpuCreationTime() metav1.Time {
+	return metav1.Time{Time: time.Now()}
+}
+
+func coolCpuCreationTime() metav1.Time {
+	return metav1.Time{Time: time.Now().Add(-3 * time.Minute)}
+}
+
+func (tc *testCase) runTestWithController(t *testing.T, hpaController *HorizontalController, informerFactory informers.SharedInformerFactory) {
+	stop := make(chan struct{})
+	defer close(stop)
+	informerFactory.Start(stop)
+	go hpaController.Run(stop)
+
+	tc.Lock()
+	if tc.verifyEvents {
+		tc.Unlock()
+		// We need to wait for events to be broadcasted (sleep for longer than record.sleepDuration).
+		time.Sleep(2 * time.Second)
+	} else {
+		tc.Unlock()
+	}
+	// Wait for HPA to be processed.
+	<-tc.processed
+	tc.verifyResults(t)
+}
+
+func (tc *testCase) runTest(t *testing.T) {
+	hpaController, informerFactory := tc.setupController(t)
+	tc.runTestWithController(t, hpaController, informerFactory)
+}
+
+func TestScaleUpUnreadyMoreScale(t *testing.T) {
+	tc := testCase{
+		minReplicas:             2,
+		maxReplicas:             6,
+		initialReplicas:         3,
+		expectedDesiredReplicas: 4,
+		MemoryTarget:            300,
+		reportedMemoryLevels:    []uint64{300, 300, 300},
+		reportedMemoryRequests:  []resource.Quantity{resource.MustParse("300Mi"), resource.MustParse("300Mi"), resource.MustParse("300Mi")},
+		reportedPodReadiness:    []v1.ConditionStatus{v1.ConditionFalse, v1.ConditionFalse, v1.ConditionFalse},
+		useMetricsAPI:           true,
+	}
+	tc.runTest(t)
+}
No results found