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descheduler/pkg/rescheduler/strategies/lownodeutilization.go

271 lines
8.5 KiB
Go

/*
Copyright 2017 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 strategies
import (
"fmt"
"sort"
"k8s.io/apimachinery/pkg/api/resource"
"k8s.io/kubernetes/pkg/api/v1"
helper "k8s.io/kubernetes/pkg/api/v1/resource"
"k8s.io/kubernetes/pkg/client/clientset_generated/clientset"
"github.com/aveshagarwal/rescheduler/pkg/api"
"github.com/aveshagarwal/rescheduler/pkg/rescheduler/evictions"
podutil "github.com/aveshagarwal/rescheduler/pkg/rescheduler/pod"
)
type NodeUsageMap struct {
node *v1.Node
usage api.ResourceThresholds
bePods []*v1.Pod
nonRemovablePods []*v1.Pod
otherPods []*v1.Pod
}
type NodePodsMap map[*v1.Node][]*v1.Pod
func LowNodeUtilization(client clientset.Interface, strategy api.ReschedulerStrategy, evictionPolicyGroupVersion string, nodes []*v1.Node) {
if !strategy.Enabled {
return
}
// todo: move to config validation?
thresholds := strategy.Params.NodeResourceUtilizationThresholds.Thresholds
if thresholds == nil {
fmt.Printf("no resource threshold is configured\n")
return
} else {
found := false
for name, _ := range thresholds {
if name == v1.ResourceCPU || name == v1.ResourceMemory || name == v1.ResourcePods {
found = true
break
}
}
if !found {
fmt.Printf("one of cpu, memory, or pods resource threshold must be configured\n")
return
}
}
targetThresholds := strategy.Params.NodeResourceUtilizationThresholds.TargetThresholds
if targetThresholds == nil {
fmt.Printf("no target resource threshold is configured\n")
return
} else if _, ok := targetThresholds[v1.ResourcePods]; !ok {
fmt.Printf("no target resource threshold for pods is configured\n")
return
}
npm := CreateNodePodsMap(client, nodes)
lowNodes, targetNodes, otherNodes := []NodeUsageMap{}, []NodeUsageMap{}, []NodeUsageMap{}
for node, pods := range npm {
usage, bePods, nonRemovablePods, otherPods := NodeUtilization(node, pods)
nuMap := NodeUsageMap{node, usage, bePods, nonRemovablePods, otherPods}
fmt.Printf("Node %#v usage: %#v\n", node.Name, usage)
if IsNodeWithLowUtilization(usage, thresholds) {
lowNodes = append(lowNodes, nuMap)
} else if IsNodeAboveTargetUtilization(usage, targetThresholds) {
targetNodes = append(targetNodes, nuMap)
} else {
otherNodes = append(otherNodes, nuMap)
}
}
if len(lowNodes) == 0 {
fmt.Printf("No node is underutilized\n")
return
} else if len(lowNodes) < strategy.Params.NodeResourceUtilizationThresholds.NumberOfNodes {
fmt.Printf("number of nodes underutilized is less than NumberOfNodes\n")
return
} else if len(lowNodes) == len(nodes) {
fmt.Printf("all nodes are underutilized\n")
return
} else if len(targetNodes) == 0 {
fmt.Printf("no node is above target utilization\n")
return
}
SortNodesByUsage(targetNodes)
// total number of pods to be moved
var totalPods float64
for _, node := range lowNodes {
podsPercentage := targetThresholds[v1.ResourcePods] - node.usage[v1.ResourcePods]
nodeCapcity := node.node.Status.Capacity
if len(node.node.Status.Allocatable) > 0 {
nodeCapcity = node.node.Status.Allocatable
}
totalPods += ((float64(podsPercentage) * float64(nodeCapcity.Pods().Value())) / 100)
}
for _, node := range targetNodes {
nodePodsUsage := node.usage[v1.ResourcePods]
nodeCapcity := node.node.Status.Capacity
if len(node.node.Status.Allocatable) > 0 {
nodeCapcity = node.node.Status.Allocatable
}
onePodPercentage := api.Percentage((float64(1) * 100) / float64(nodeCapcity.Pods().Value()))
if nodePodsUsage > targetThresholds[v1.ResourcePods] && totalPods > 0 {
for _, pod := range node.bePods {
success, err := evictions.EvictPod(client, pod, evictionPolicyGroupVersion)
if !success {
fmt.Printf("Error when evicting pod: %#v (%#v)\n", pod.Name, err)
} else {
fmt.Printf("Evicted pod: %#v (%#v)\n", pod.Name, err)
nodePodsUsage = nodePodsUsage - onePodPercentage
totalPods--
if nodePodsUsage <= targetThresholds[v1.ResourcePods] || totalPods <= 0 {
break
}
}
}
if nodePodsUsage > targetThresholds[v1.ResourcePods] && totalPods > 0 {
for _, pod := range node.otherPods {
success, err := evictions.EvictPod(client, pod, evictionPolicyGroupVersion)
if !success {
fmt.Printf("Error when evicting pod: %#v (%#v)\n", pod.Name, err)
} else {
fmt.Printf("Evicted pod: %#v (%#v)\n", pod.Name, err)
nodePodsUsage = nodePodsUsage - onePodPercentage
totalPods--
if nodePodsUsage <= targetThresholds[v1.ResourcePods] || totalPods <= 0 {
break
}
}
}
}
}
}
}
func SortNodesByUsage(nodes []NodeUsageMap) {
sort.Slice(nodes, func(i, j int) bool {
var ti, tj api.Percentage
for name, value := range nodes[i].usage {
if name == v1.ResourceCPU || name == v1.ResourceMemory || name == v1.ResourcePods {
ti += value
}
}
for name, value := range nodes[j].usage {
if name == v1.ResourceCPU || name == v1.ResourceMemory || name == v1.ResourcePods {
tj += value
}
}
// To return sorted in descending order
return ti > tj
})
}
func CreateNodePodsMap(client clientset.Interface, nodes []*v1.Node) NodePodsMap {
npm := NodePodsMap{}
for _, node := range nodes {
pods, err := podutil.ListPodsOnANode(client, node)
if err != nil {
fmt.Printf("node %s will not be processed, error in accessing its pods (%#v)\n", node.Name, err)
} else {
npm[node] = pods
}
}
return npm
}
func IsNodeAboveTargetUtilization(nodeThresholds api.ResourceThresholds, thresholds api.ResourceThresholds) bool {
for name, nodeValue := range nodeThresholds {
if name == v1.ResourceCPU || name == v1.ResourceMemory || name == v1.ResourcePods {
if value, ok := thresholds[name]; !ok {
continue
} else if nodeValue > value {
return true
}
}
}
return false
}
func IsNodeWithLowUtilization(nodeThresholds api.ResourceThresholds, thresholds api.ResourceThresholds) bool {
for name, nodeValue := range nodeThresholds {
if name == v1.ResourceCPU || name == v1.ResourceMemory || name == v1.ResourcePods {
if value, ok := thresholds[name]; !ok {
continue
} else if nodeValue > value {
return false
}
}
}
return true
}
func NodeUtilization(node *v1.Node, pods []*v1.Pod) (api.ResourceThresholds, []*v1.Pod, []*v1.Pod, []*v1.Pod) {
bePods := []*v1.Pod{}
nonRemovablePods := []*v1.Pod{}
otherPods := []*v1.Pod{}
totalReqs := map[v1.ResourceName]resource.Quantity{}
for _, pod := range pods {
sr, err := podutil.CreatorRef(pod)
if err != nil {
sr = nil
}
if podutil.IsMirrorPod(pod) || podutil.IsPodWithLocalStorage(pod) || sr == nil || podutil.IsDaemonsetPod(sr) || podutil.IsCriticalPod(pod) {
nonRemovablePods = append(nonRemovablePods, pod)
if podutil.IsBestEffortPod(pod) {
continue
}
} else if podutil.IsBestEffortPod(pod) {
bePods = append(bePods, pod)
continue
} else {
// todo: differentiate between burstable and guranteed pods
otherPods = append(otherPods, pod)
}
req, _, err := helper.PodRequestsAndLimits(pod)
if err != nil {
fmt.Printf("Error computing resource usage of pod, ignoring: %#v\n", pod.Name)
continue
}
for name, quantity := range req {
if name == v1.ResourceCPU || name == v1.ResourceMemory {
if value, ok := totalReqs[name]; !ok {
totalReqs[name] = *quantity.Copy()
} else {
value.Add(quantity)
totalReqs[name] = value
}
}
}
}
nodeCapcity := node.Status.Capacity
if len(node.Status.Allocatable) > 0 {
nodeCapcity = node.Status.Allocatable
}
usage := api.ResourceThresholds{}
totalCPUReq := totalReqs[v1.ResourceCPU]
totalMemReq := totalReqs[v1.ResourceMemory]
totalPods := len(pods)
usage[v1.ResourceCPU] = api.Percentage((float64(totalCPUReq.MilliValue()) * 100) / float64(nodeCapcity.Cpu().MilliValue()))
usage[v1.ResourceMemory] = api.Percentage(float64(totalMemReq.Value()) / float64(nodeCapcity.Memory().Value()) * 100)
usage[v1.ResourcePods] = api.Percentage((float64(totalPods) * 100) / float64(nodeCapcity.Pods().Value()))
return usage, bePods, nonRemovablePods, otherPods
}