| /* |
| 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 qos |
| |
| import ( |
| "k8s.io/api/core/v1" |
| v1qos "k8s.io/kubernetes/pkg/apis/core/v1/helper/qos" |
| ) |
| |
| const ( |
| // PodInfraOOMAdj is very docker specific. For arbitrary runtime, it may not make |
| // sense to set sandbox level oom score, e.g. a sandbox could only be a namespace |
| // without a process. |
| // TODO: Handle infra container oom score adj in a runtime agnostic way. |
| PodInfraOOMAdj int = -998 |
| KubeletOOMScoreAdj int = -999 |
| DockerOOMScoreAdj int = -999 |
| KubeProxyOOMScoreAdj int = -999 |
| guaranteedOOMScoreAdj int = -998 |
| besteffortOOMScoreAdj int = 1000 |
| ) |
| |
| // GetContainerOOMAdjust returns the amount by which the OOM score of all processes in the |
| // container should be adjusted. |
| // The OOM score of a process is the percentage of memory it consumes |
| // multiplied by 10 (barring exceptional cases) + a configurable quantity which is between -1000 |
| // and 1000. Containers with higher OOM scores are killed if the system runs out of memory. |
| // See https://lwn.net/Articles/391222/ for more information. |
| func GetContainerOOMScoreAdjust(pod *v1.Pod, container *v1.Container, memoryCapacity int64) int { |
| switch v1qos.GetPodQOS(pod) { |
| case v1.PodQOSGuaranteed: |
| // Guaranteed containers should be the last to get killed. |
| return guaranteedOOMScoreAdj |
| case v1.PodQOSBestEffort: |
| return besteffortOOMScoreAdj |
| } |
| |
| // Burstable containers are a middle tier, between Guaranteed and Best-Effort. Ideally, |
| // we want to protect Burstable containers that consume less memory than requested. |
| // The formula below is a heuristic. A container requesting for 10% of a system's |
| // memory will have an OOM score adjust of 900. If a process in container Y |
| // uses over 10% of memory, its OOM score will be 1000. The idea is that containers |
| // which use more than their request will have an OOM score of 1000 and will be prime |
| // targets for OOM kills. |
| // Note that this is a heuristic, it won't work if a container has many small processes. |
| memoryRequest := container.Resources.Requests.Memory().Value() |
| oomScoreAdjust := 1000 - (1000*memoryRequest)/memoryCapacity |
| // A guaranteed pod using 100% of memory can have an OOM score of 10. Ensure |
| // that burstable pods have a higher OOM score adjustment. |
| if int(oomScoreAdjust) < (1000 + guaranteedOOMScoreAdj) { |
| return (1000 + guaranteedOOMScoreAdj) |
| } |
| // Give burstable pods a higher chance of survival over besteffort pods. |
| if int(oomScoreAdjust) == besteffortOOMScoreAdj { |
| return int(oomScoreAdjust - 1) |
| } |
| return int(oomScoreAdjust) |
| } |