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Distribute pods efficiently in CA scalability tests

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Instead of using runReplicatedPodOnEachNode method
which is suited to a small number of nodes,
distribute pods on the nodes with desired load
using RCs that eat up all the space we want to be
empty after distribution.
This commit is contained in:
Beata Skiba 2017-08-23 12:02:55 +02:00
parent a4b719dcab
commit 6e08007ce1
1 changed files with 67 additions and 26 deletions
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93
test/e2e/autoscaling/cluster_autoscaler_scalability.go
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@ -38,7 +38,7 @@ import (
const (
memoryReservationTimeout = 5 * time.Minute
largeResizeTimeout = 10 * time.Minute
largeResizeTimeout = 8 * time.Minute
largeScaleUpTimeout = 10 * time.Minute
largeScaleDownTimeout = 20 * time.Minute
minute = 1 * time.Minute
@ -220,16 +220,21 @@ var _ = framework.KubeDescribe("Cluster size autoscaler scalability [Slow]", fun
})
It("should scale down underutilized nodes [Feature:ClusterAutoscalerScalability4]", func() {
underutilizedReservation := int64(float64(memCapacityMb) * 0.01)
fullReservation := int64(float64(memCapacityMb) * 0.8)
perNodeReplicas := 10
perPodReservation := int(float64(memCapacityMb) * 0.01)
// underutilizedNodes are 10% full
underutilizedPerNodeReplicas := 10
// fullNodes are 70% full
fullPerNodeReplicas := 70
totalNodes := maxNodes
underutilizedRatio := 0.3
maxDelta := 30
// 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
@ -241,36 +246,32 @@ var _ = framework.KubeDescribe("Cluster size autoscaler scalability [Slow]", fun
}.AsSelector().String(),
})
framework.ExpectNoError(err)
framework.ExpectNoError(addAnnotation(f, nodes.Items, ScaleDownDisabledKey, "true"))
// distribute pods (using taints)
divider := int(float64(len(nodes.Items)) * 0.7)
// distribute pods using replication controllers taking up space that should
// be empty after pods are distributed
underutilizedNodesNum := int(float64(maxNodes) * underutilizedRatio)
fullNodesNum := totalNodes - underutilizedNodesNum
fullNodes := nodes.Items[:divider]
underutilizedNodes := nodes.Items[divider:]
podDistribution := []podBatch{
{numNodes: fullNodesNum, podsPerNode: fullPerNodeReplicas},
{numNodes: underutilizedNodesNum, podsPerNode: underutilizedPerNodeReplicas}}
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)
cleanup := distributeLoad(f, f.Namespace.Name, "10-70", podDistribution, perPodReservation,
int(0.95*float64(memCapacityMb)), map[string]string{}, largeScaleUpTimeout)
defer cleanup()
framework.ExpectNoError(err)
framework.ExpectNoError(makeSchedulable(f, nodes.Items))
// enable scale down again
framework.ExpectNoError(addAnnotation(f, nodes.Items, ScaleDownDisabledKey, "false"))
// wait for scale down
expectedSize := int(float64(totalNodes) * 0.85)
nodesToScaleDownCount := totalNodes - expectedSize
// wait for scale down to start. Node deletion takes a long time, so we just
// wait for maximum of 30 nodes deleted
nodesToScaleDownCount := int(float64(totalNodes) * 0.1)
if nodesToScaleDownCount > maxDelta {
nodesToScaleDownCount = maxDelta
}
expectedSize := totalNodes - nodesToScaleDownCount
timeout := time.Duration(nodesToScaleDownCount)*time.Minute + scaleDownTimeout
framework.ExpectNoError(WaitForClusterSizeFunc(f.ClientSet, func(size int) bool {
return size <= expectedSize
@ -453,6 +454,46 @@ func createHostPortPodsWithMemory(f *framework.Framework, id string, replicas, p
}
}
type podBatch struct {
numNodes int
podsPerNode int
}
// distributeLoad distributes the pods in the way described by podDostribution,
// assuming all pods will have the same memory reservation and all nodes the same
// memory capacity. This allows us generate the load on the cluster in the exact
// way that we want.
//
// To achieve this we do the following:
// 1. Create replication controllers that eat up all the space that should be
// empty after setup, making sure they end up on different nodes by specifying
// conflicting host port
// 2. Create targer RC that will generate the load on the cluster
// 3. Remove the rcs created in 1.
func distributeLoad(f *framework.Framework, namespace string, id string, podDistribution []podBatch,
podMemRequestMegabytes int, nodeMemCapacity int, labels map[string]string, timeout time.Duration) func() error {
port := 8013
// Create load-distribution RCs with one pod per node, reserving all remaining
// memory to force the distribution of pods for the target RCs.
// The load-distribution RCs will be deleted on function return.
totalPods := 0
for i, podBatch := range podDistribution {
totalPods += podBatch.numNodes * podBatch.podsPerNode
remainingMem := nodeMemCapacity - podBatch.podsPerNode*podMemRequestMegabytes
replicas := podBatch.numNodes
cleanup := createHostPortPodsWithMemory(f, fmt.Sprintf("load-distribution%d", i), replicas, port, remainingMem*replicas, timeout)
defer cleanup()
}
framework.ExpectNoError(waitForAllCaPodsReadyInNamespace(f, f.ClientSet))
// Create the target RC
rcConfig := reserveMemoryRCConfig(f, id, totalPods, totalPods*podMemRequestMegabytes, timeout)
framework.ExpectNoError(framework.RunRC(*rcConfig))
framework.ExpectNoError(waitForAllCaPodsReadyInNamespace(f, f.ClientSet))
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)