Merge pull request #50450 from aleksandra-malinowska/scalability-tests-clean

Automatic merge from submit-queue

Add Cluster Autoscaler scalability test suite

This suite is intended for manually testing Cluster Autoscaler on large clusters. It isn't supposed to be run automatically (at least for now).

It can be run on Kubemark (with #50440) with the following setup:
- start Kubemark with NUM_NODES=1 (as we require there to be exactly 1 replica per hollow-node replication controller in this setup)
- set kubemark-master machine type manually to appropriate type for the Kubemark cluster size. Maximum Kubemark cluster size reached in test run is defined by maxNodes constant, so for maxNodes=1000, please upgrade to n1-standard-32. Adjust if modifying maxNodes.
- start Cluster Autoscaler pod in the external cluster using image built from version with Kubemark cloud provider (release pending)
- for grabbing metrics from ClusterAutoscaler (with #50382), add "--include-cluster-autoscaler=true" parameter in addition to regular flags for gathering components' metrics/resource usage during e2e tests

cc @bskiba

test/e2e/autoscaling/BUILD

@@ -11,6 +11,7 @@ go_library(
     name = "go_default_library",
     srcs = [
         "autoscaling_timer.go",
+        "cluster_autoscaler_scalability.go",
         "cluster_size_autoscaling.go",
         "dns_autoscaling.go",
         "framework.go",
@@ -33,9 +34,11 @@ go_library(
         "//vendor/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/fields:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/labels:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/types:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/errors:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/intstr:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/sets:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/util/strategicpatch:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/uuid:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/wait:go_default_library",
         "//vendor/k8s.io/client-go/kubernetes:go_default_library",

test/e2e/autoscaling/cluster_autoscaler_scalability.go

@@ -0,0 +1,458 @@
+/*
+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 autoscaling
+
+import (
+	"encoding/json"
+	"fmt"
+	"strings"
+	"time"
+
+	"k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/fields"
+	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/apimachinery/pkg/util/strategicpatch"
+	clientset "k8s.io/client-go/kubernetes"
+	"k8s.io/kubernetes/test/e2e/framework"
+	testutils "k8s.io/kubernetes/test/utils"
+
+	"github.com/golang/glog"
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+const (
+	largeResizeTimeout    = 10 * time.Minute
+	largeScaleUpTimeout   = 10 * time.Minute
+	largeScaleDownTimeout = 20 * time.Minute
+	minute                = 1 * time.Minute
+
+	maxNodes = 1000
+)
+
+type clusterPredicates struct {
+	nodes int
+}
+
+type scaleUpTestConfig struct {
+	initialNodes   int
+	initialPods    int
+	extraPods      *testutils.RCConfig
+	expectedResult *clusterPredicates
+}
+
+var _ = framework.KubeDescribe("Cluster size autoscaler scalability [Slow]", func() {
+	f := framework.NewDefaultFramework("autoscaling")
+	var c clientset.Interface
+	var nodeCount int
+	var coresPerNode int
+	var memCapacityMb int
+	var originalSizes map[string]int
+	var sum int
+
+	BeforeEach(func() {
+		framework.SkipUnlessProviderIs("gce", "gke", "kubemark")
+
+		c = f.ClientSet
+		if originalSizes == nil {
+			originalSizes = make(map[string]int)
+			sum = 0
+			for _, mig := range strings.Split(framework.TestContext.CloudConfig.NodeInstanceGroup, ",") {
+				size, err := framework.GroupSize(mig)
+				framework.ExpectNoError(err)
+				By(fmt.Sprintf("Initial size of %s: %d", mig, size))
+				originalSizes[mig] = size
+				sum += size
+			}
+		}
+
+		framework.ExpectNoError(framework.WaitForClusterSize(c, sum, scaleUpTimeout))
+
+		nodes := framework.GetReadySchedulableNodesOrDie(f.ClientSet)
+		nodeCount = len(nodes.Items)
+		Expect(nodeCount).NotTo(BeZero())
+		cpu := nodes.Items[0].Status.Capacity[v1.ResourceCPU]
+		mem := nodes.Items[0].Status.Capacity[v1.ResourceMemory]
+		coresPerNode = int((&cpu).MilliValue() / 1000)
+		memCapacityMb = int((&mem).Value() / 1024 / 1024)
+
+		Expect(nodeCount).Should(Equal(sum))
+
+		if framework.ProviderIs("gke") {
+			val, err := isAutoscalerEnabled(3)
+			framework.ExpectNoError(err)
+			if !val {
+				err = enableAutoscaler("default-pool", 3, 5)
+				framework.ExpectNoError(err)
+			}
+		}
+	})
+
+	AfterEach(func() {
+		By(fmt.Sprintf("Restoring initial size of the cluster"))
+		setMigSizes(originalSizes)
+		framework.ExpectNoError(framework.WaitForClusterSize(c, nodeCount, scaleDownTimeout))
+		nodes, err := c.Core().Nodes().List(metav1.ListOptions{})
+		framework.ExpectNoError(err)
+		s := time.Now()
+	makeSchedulableLoop:
+		for start := time.Now(); time.Since(start) < makeSchedulableTimeout; time.Sleep(makeSchedulableDelay) {
+			for _, n := range nodes.Items {
+				err = makeNodeSchedulable(c, &n, true)
+				switch err.(type) {
+				case CriticalAddonsOnlyError:
+					continue makeSchedulableLoop
+				default:
+					framework.ExpectNoError(err)
+				}
+			}
+			break
+		}
+		glog.Infof("Made nodes schedulable again in %v", time.Now().Sub(s).String())
+	})
+
+	It("should scale up at all [Feature:ClusterAutoscalerScalability1]", func() {
+		perNodeReservation := int(float64(memCapacityMb) * 0.95)
+		replicasPerNode := 10
+
+		additionalNodes := maxNodes - nodeCount
+		replicas := additionalNodes * replicasPerNode
+		additionalReservation := additionalNodes * perNodeReservation
+
+		// saturate cluster
+		reservationCleanup := ReserveMemory(f, "some-pod", nodeCount*2, nodeCount*perNodeReservation, true, scaleUpTimeout)
+		defer reservationCleanup()
+		framework.ExpectNoError(waitForAllCaPodsReadyInNamespace(f, c))
+
+		// configure pending pods & expected scale up
+		rcConfig := reserveMemoryRCConfig(f, "extra-pod-1", replicas, additionalReservation, largeScaleUpTimeout)
+		expectedResult := createClusterPredicates(nodeCount + additionalNodes)
+		config := createScaleUpTestConfig(nodeCount, nodeCount, rcConfig, expectedResult)
+
+		// run test
+		testCleanup := simpleScaleUpTest(f, config)
+		defer testCleanup()
+	})
+
+	It("should scale up twice [Feature:ClusterAutoscalerScalability2]", func() {
+		perNodeReservation := int(float64(memCapacityMb) * 0.95)
+		replicasPerNode := 10
+		additionalNodes1 := int(0.7 * maxNodes)
+		additionalNodes2 := int(0.25 * maxNodes)
+
+		replicas1 := additionalNodes1 * replicasPerNode
+		replicas2 := additionalNodes2 * replicasPerNode
+
+		glog.Infof("cores per node: %v", coresPerNode)
+
+		// saturate cluster
+		reservationCleanup := ReserveMemory(f, "some-pod", nodeCount, nodeCount*perNodeReservation, true, scaleUpTimeout)
+		defer reservationCleanup()
+		framework.ExpectNoError(waitForAllCaPodsReadyInNamespace(f, c))
+
+		glog.Infof("Reserved successfully")
+
+		// configure pending pods & expected scale up #1
+		rcConfig := reserveMemoryRCConfig(f, "extra-pod-1", replicas1, additionalNodes1*perNodeReservation, largeScaleUpTimeout)
+		expectedResult := createClusterPredicates(nodeCount + additionalNodes1)
+		config := createScaleUpTestConfig(nodeCount, nodeCount, rcConfig, expectedResult)
+
+		epsilon := 0.05
+
+		// run test #1
+		testCleanup1 := simpleScaleUpTestWithEpsilon(f, config, epsilon)
+		defer testCleanup1()
+
+		glog.Infof("Scaled up once")
+
+		// configure pending pods & expected scale up #2
+		rcConfig2 := reserveMemoryRCConfig(f, "extra-pod-2", replicas2, additionalNodes2*perNodeReservation, largeScaleUpTimeout)
+		expectedResult2 := createClusterPredicates(nodeCount + additionalNodes1 + additionalNodes2)
+		config2 := createScaleUpTestConfig(nodeCount+additionalNodes1, nodeCount+additionalNodes2, rcConfig2, expectedResult2)
+
+		// run test #2
+		testCleanup2 := simpleScaleUpTestWithEpsilon(f, config2, epsilon)
+		defer testCleanup2()
+
+		glog.Infof("Scaled up twice")
+	})
+
+	It("should scale down empty nodes [Feature:ClusterAutoscalerScalability3]", func() {
+		perNodeReservation := int(float64(memCapacityMb) * 0.7)
+		replicas := int(float64(maxNodes) * 0.7)
+		totalNodes := maxNodes
+
+		// resize cluster to totalNodes
+		newSizes := map[string]int{
+			anyKey(originalSizes): totalNodes,
+		}
+		setMigSizes(newSizes)
+		framework.ExpectNoError(framework.WaitForClusterSize(f.ClientSet, totalNodes, largeResizeTimeout))
+
+		// run replicas
+		rcConfig := reserveMemoryRCConfig(f, "some-pod", replicas, replicas*perNodeReservation, largeScaleUpTimeout)
+		expectedResult := createClusterPredicates(totalNodes)
+		config := createScaleUpTestConfig(totalNodes, totalNodes, rcConfig, expectedResult)
+		testCleanup := simpleScaleUpTestWithEpsilon(f, config, 0.1)
+		defer testCleanup()
+
+		// check if empty nodes are scaled down
+		framework.ExpectNoError(WaitForClusterSizeFunc(f.ClientSet,
+			func(size int) bool {
+				return size <= replicas+3 // leaving space for non-evictable kube-system pods
+			}, scaleDownTimeout))
+	})
+
+	It("should scale down underutilized nodes [Feature:ClusterAutoscalerScalability4]", func() {
+		underutilizedReservation := int64(float64(memCapacityMb) * 0.01)
+		fullReservation := int64(float64(memCapacityMb) * 0.8)
+		perNodeReplicas := 10
+		totalNodes := maxNodes
+
+		// resize cluster to totalNodes
+		newSizes := map[string]int{
+			anyKey(originalSizes): totalNodes,
+		}
+		setMigSizes(newSizes)
+		framework.ExpectNoError(framework.WaitForClusterSize(f.ClientSet, totalNodes, largeResizeTimeout))
+
+		// annotate all nodes with no-scale-down
+		ScaleDownDisabledKey := "cluster-autoscaler.kubernetes.io/scale-down-disabled"
+
+		nodes, err := f.ClientSet.Core().Nodes().List(metav1.ListOptions{
+			FieldSelector: fields.Set{
+				"spec.unschedulable": "false",
+			}.AsSelector().String(),
+		})
+
+		framework.ExpectNoError(addAnnotation(f, nodes.Items, ScaleDownDisabledKey, "true"))
+
+		// distribute pods (using taints)
+		divider := int(float64(len(nodes.Items)) * 0.7)
+
+		fullNodes := nodes.Items[:divider]
+		underutilizedNodes := nodes.Items[divider:]
+
+		framework.ExpectNoError(makeUnschedulable(f, underutilizedNodes))
+
+		testId2 := "full"
+		labels2 := map[string]string{"test_id": testId2}
+		cleanup2, err := runReplicatedPodOnEachNodeWithCleanup(f, fullNodes, f.Namespace.Name, 1, "filling-pod", labels2, fullReservation)
+		defer cleanup2()
+		framework.ExpectNoError(err)
+
+		framework.ExpectNoError(makeUnschedulable(f, fullNodes))
+
+		testId := "underutilized"
+		labels := map[string]string{"test_id": testId}
+		cleanup, err := runReplicatedPodOnEachNodeWithCleanup(f, underutilizedNodes, f.Namespace.Name, perNodeReplicas, "underutilizing-pod", labels, underutilizedReservation)
+		defer cleanup()
+		framework.ExpectNoError(err)
+
+		framework.ExpectNoError(makeSchedulable(f, nodes.Items))
+		framework.ExpectNoError(addAnnotation(f, nodes.Items, ScaleDownDisabledKey, "false"))
+
+		// wait for scale down
+		expectedSize := int(float64(totalNodes) * 0.85)
+		nodesToScaleDownCount := totalNodes - expectedSize
+		timeout := time.Duration(nodesToScaleDownCount)*time.Minute + scaleDownTimeout
+		framework.ExpectNoError(WaitForClusterSizeFunc(f.ClientSet, func(size int) bool {
+			return size <= expectedSize
+		}, timeout))
+	})
+
+	It("shouldn't scale down with underutilized nodes due to host port conflicts [Feature:ClusterAutoscalerScalability5]", func() {
+		fullReservation := int(float64(memCapacityMb) * 0.9)
+		hostPortPodReservation := int(float64(memCapacityMb) * 0.3)
+		totalNodes := maxNodes
+		reservedPort := 4321
+
+		// resize cluster to totalNodes
+		newSizes := map[string]int{
+			anyKey(originalSizes): totalNodes,
+		}
+		setMigSizes(newSizes)
+		framework.ExpectNoError(framework.WaitForClusterSize(f.ClientSet, totalNodes, largeResizeTimeout))
+		divider := int(float64(totalNodes) * 0.7)
+		fullNodesCount := divider
+		underutilizedNodesCount := totalNodes - fullNodesCount
+
+		By("Reserving full nodes")
+		// run RC1 w/o host port
+		cleanup := ReserveMemory(f, "filling-pod", fullNodesCount, fullNodesCount*fullReservation, true, largeScaleUpTimeout*2)
+		defer cleanup()
+
+		By("Reserving host ports on remaining nodes")
+		// run RC2 w/ host port
+		cleanup2 := createHostPortPodsWithMemory(f, "underutilizing-host-port-pod", underutilizedNodesCount, reservedPort, underutilizedNodesCount*hostPortPodReservation, largeScaleUpTimeout)
+		defer cleanup2()
+
+		waitForAllCaPodsReadyInNamespace(f, c)
+		// wait and check scale down doesn't occur
+		By(fmt.Sprintf("Sleeping %v minutes...", scaleDownTimeout.Minutes()))
+		time.Sleep(scaleDownTimeout)
+
+		By("Checking if the number of nodes is as expected")
+		nodes := framework.GetReadySchedulableNodesOrDie(f.ClientSet)
+		glog.Infof("Nodes: %v, expected: %v", len(nodes.Items), totalNodes)
+		Expect(len(nodes.Items)).Should(Equal(totalNodes))
+	})
+
+})
+
+func makeUnschedulable(f *framework.Framework, nodes []v1.Node) error {
+	for _, node := range nodes {
+		err := makeNodeUnschedulable(f.ClientSet, &node)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func makeSchedulable(f *framework.Framework, nodes []v1.Node) error {
+	for _, node := range nodes {
+		err := makeNodeSchedulable(f.ClientSet, &node, false)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func anyKey(input map[string]int) string {
+	for k := range input {
+		return k
+	}
+	return ""
+}
+
+func simpleScaleUpTestWithEpsilon(f *framework.Framework, config *scaleUpTestConfig, epsilon float64) func() error {
+	// resize cluster to start size
+	// run rc based on config
+	By(fmt.Sprintf("Running RC %v from config", config.extraPods.Name))
+	start := time.Now()
+	framework.ExpectNoError(framework.RunRC(*config.extraPods))
+	// check results
+	if epsilon > 0 && epsilon < 1 {
+		// Tolerate some number of nodes not to be created.
+		minExpectedNodeCount := int(float64(config.expectedResult.nodes) - epsilon*float64(config.expectedResult.nodes))
+		framework.ExpectNoError(WaitForClusterSizeFunc(f.ClientSet,
+			func(size int) bool { return size >= minExpectedNodeCount }, scaleUpTimeout))
+	} else {
+		framework.ExpectNoError(framework.WaitForClusterSize(f.ClientSet, config.expectedResult.nodes, scaleUpTimeout))
+	}
+	glog.Infof("cluster is increased")
+	if epsilon > 0 && epsilon < 0 {
+		framework.ExpectNoError(waitForCaPodsReadyInNamespace(f, f.ClientSet, int(epsilon*float64(config.extraPods.Replicas)+1)))
+	} else {
+		framework.ExpectNoError(waitForAllCaPodsReadyInNamespace(f, f.ClientSet))
+	}
+	timeTrack(start, fmt.Sprintf("Scale up to %v", config.expectedResult.nodes))
+	return func() error {
+		return framework.DeleteRCAndPods(f.ClientSet, f.InternalClientset, f.Namespace.Name, config.extraPods.Name)
+	}
+}
+
+func simpleScaleUpTest(f *framework.Framework, config *scaleUpTestConfig) func() error {
+	return simpleScaleUpTestWithEpsilon(f, config, 0)
+}
+
+func reserveMemoryRCConfig(f *framework.Framework, id string, replicas, megabytes int, timeout time.Duration) *testutils.RCConfig {
+	return &testutils.RCConfig{
+		Client:         f.ClientSet,
+		InternalClient: f.InternalClientset,
+		Name:           id,
+		Namespace:      f.Namespace.Name,
+		Timeout:        timeout,
+		Image:          framework.GetPauseImageName(f.ClientSet),
+		Replicas:       replicas,
+		MemRequest:     int64(1024 * 1024 * megabytes / replicas),
+	}
+}
+
+func createScaleUpTestConfig(nodes, pods int, extraPods *testutils.RCConfig, expectedResult *clusterPredicates) *scaleUpTestConfig {
+	return &scaleUpTestConfig{
+		initialNodes:   nodes,
+		initialPods:    pods,
+		extraPods:      extraPods,
+		expectedResult: expectedResult,
+	}
+}
+
+func createClusterPredicates(nodes int) *clusterPredicates {
+	return &clusterPredicates{
+		nodes: nodes,
+	}
+}
+
+func addAnnotation(f *framework.Framework, nodes []v1.Node, key, value string) error {
+	for _, node := range nodes {
+		oldData, err := json.Marshal(node)
+		if err != nil {
+			return err
+		}
+
+		if node.Annotations == nil {
+			node.Annotations = make(map[string]string)
+		}
+		node.Annotations[key] = value
+
+		newData, err := json.Marshal(node)
+		if err != nil {
+			return err
+		}
+
+		patchBytes, err := strategicpatch.CreateTwoWayMergePatch(oldData, newData, v1.Node{})
+		if err != nil {
+			return err
+		}
+
+		_, err = f.ClientSet.Core().Nodes().Patch(string(node.Name), types.StrategicMergePatchType, patchBytes)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func createHostPortPodsWithMemory(f *framework.Framework, id string, replicas, port, megabytes int, timeout time.Duration) func() error {
+	By(fmt.Sprintf("Running RC which reserves host port and memory"))
+	request := int64(1024 * 1024 * megabytes / replicas)
+	config := &testutils.RCConfig{
+		Client:         f.ClientSet,
+		InternalClient: f.InternalClientset,
+		Name:           id,
+		Namespace:      f.Namespace.Name,
+		Timeout:        timeout,
+		Image:          framework.GetPauseImageName(f.ClientSet),
+		Replicas:       replicas,
+		HostPorts:      map[string]int{"port1": port},
+		MemRequest:     request,
+	}
+	err := framework.RunRC(*config)
+	framework.ExpectNoError(err)
+	return func() error {
+		return framework.DeleteRCAndPods(f.ClientSet, f.InternalClientset, f.Namespace.Name, id)
+	}
+}
+
+func timeTrack(start time.Time, name string) {
+	elapsed := time.Since(start)
+	glog.Infof("%s took %s", name, elapsed)
+}

test/e2e/autoscaling/cluster_size_autoscaling.go

@@ -199,7 +199,7 @@ var _ = SIGDescribe("Cluster size autoscaling [Slow]", func() {
 		framework.ExpectNoError(err)
 		unmanagedNodes := nodeCount - status.ready
 
-		By("Schedule more pods than can fit and wait for claster to scale-up")
+		By("Schedule more pods than can fit and wait for cluster to scale-up")
 		ReserveMemory(f, "memory-reservation", 100, nodeCount*memCapacityMb, false, 1*time.Second)
 		defer framework.DeleteRCAndPods(f.ClientSet, f.InternalClientset, f.Namespace.Name, "memory-reservation")
 
@@ -719,7 +719,7 @@ func runDrainTest(f *framework.Framework, migSizes map[string]int, namespace str
 	numPods := len(nodes.Items) * podsPerNode
 	testId := string(uuid.NewUUID()) // So that we can label and find pods
 	labelMap := map[string]string{"test_id": testId}
-	framework.ExpectNoError(runReplicatedPodOnEachNode(f, nodes.Items, namespace, podsPerNode, "reschedulable-pods", labelMap))
+	framework.ExpectNoError(runReplicatedPodOnEachNode(f, nodes.Items, namespace, podsPerNode, "reschedulable-pods", labelMap, 0))
 
 	defer framework.DeleteRCAndPods(f.ClientSet, f.InternalClientset, namespace, "reschedulable-pods")
 
@@ -907,7 +907,7 @@ func doPut(url, content string) (string, error) {
 	return strBody, nil
 }
 
-func ReserveMemory(f *framework.Framework, id string, replicas, megabytes int, expectRunning bool, timeout time.Duration) {
+func ReserveMemory(f *framework.Framework, id string, replicas, megabytes int, expectRunning bool, timeout time.Duration) func() error {
 	By(fmt.Sprintf("Running RC which reserves %v MB of memory", megabytes))
 	request := int64(1024 * 1024 * megabytes / replicas)
 	config := &testutils.RCConfig{
@@ -929,9 +929,12 @@ func ReserveMemory(f *framework.Framework, id string, replicas, megabytes int, e
 		if expectRunning {
 			framework.ExpectNoError(err)
 		}
-		return
+		return func() error {
+			return framework.DeleteRCAndPods(f.ClientSet, f.InternalClientset, f.Namespace.Name, id)
+		}
 	}
 	framework.Failf("Failed to reserve memory within timeout")
+	return nil
 }
 
 // WaitForClusterSize waits until the cluster size matches the given function.
@@ -961,7 +964,7 @@ func WaitForClusterSizeFuncWithUnready(c clientset.Interface, sizeFunc func(int)
 			glog.Infof("Cluster has reached the desired size")
 			return nil
 		}
-		glog.Infof("Waiting for cluster, current size %d, not ready nodes %d", numNodes, numNodes-numReady)
+		glog.Infof("Waiting for cluster with func, current size %d, not ready nodes %d", numNodes, numNodes-numReady)
 	}
 	return fmt.Errorf("timeout waiting %v for appropriate cluster size", timeout)
 }
@@ -1201,7 +1204,7 @@ func buildAntiAffinity(labels map[string]string) *v1.Affinity {
 // 3. for each node:
 // 3a. enable scheduling on that node
 // 3b. increase number of replicas in RC by podsPerNode
-func runReplicatedPodOnEachNode(f *framework.Framework, nodes []v1.Node, namespace string, podsPerNode int, id string, labels map[string]string) error {
+func runReplicatedPodOnEachNode(f *framework.Framework, nodes []v1.Node, namespace string, podsPerNode int, id string, labels map[string]string, memRequest int64) error {
 	By("Run a pod on each node")
 	for _, node := range nodes {
 		err := makeNodeUnschedulable(f.ClientSet, &node)
@@ -1223,6 +1226,7 @@ func runReplicatedPodOnEachNode(f *framework.Framework, nodes []v1.Node, namespa
 		Image:          framework.GetPauseImageName(f.ClientSet),
 		Replicas:       0,
 		Labels:         labels,
+		MemRequest:     memRequest,
 	}
 	err := framework.RunRC(*config)
 	if err != nil {
@@ -1274,6 +1278,14 @@ func runReplicatedPodOnEachNode(f *framework.Framework, nodes []v1.Node, namespa
 	return nil
 }
 
+// wrap runReplicatedPodOnEachNode to return cleanup
+func runReplicatedPodOnEachNodeWithCleanup(f *framework.Framework, nodes []v1.Node, namespace string, podsPerNode int, id string, labels map[string]string, memRequest int64) (func(), error) {
+	err := runReplicatedPodOnEachNode(f, nodes, namespace, podsPerNode, id, labels, memRequest)
+	return func() {
+		framework.DeleteRCAndPods(f.ClientSet, f.InternalClientset, namespace, id)
+	}, err
+}
+
 // Increase cluster size by newNodesForScaledownTests to create some unused nodes
 // that can be later removed by cluster autoscaler.
 func manuallyIncreaseClusterSize(f *framework.Framework, originalSizes map[string]int) int {