/* Copyright 2019 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 noderesources import ( "k8s.io/kubernetes/pkg/scheduler/apis/config" "k8s.io/kubernetes/pkg/scheduler/framework" ) // mostResourceScorer favors nodes with most requested resources. // It calculates the percentage of memory and CPU requested by pods scheduled on the node, and prioritizes // based on the maximum of the average of the fraction of requested to capacity. // // Details: // (cpu(MaxNodeScore * requested * cpuWeight / capacity) + memory(MaxNodeScore * requested * memoryWeight / capacity) + ...) / weightSum func mostResourceScorer(resources []config.ResourceSpec) func(requested, allocable []int64) int64 { return func(requested, allocable []int64) int64 { var nodeScore, weightSum int64 for i := range requested { if allocable[i] == 0 { continue } weight := resources[i].Weight resourceScore := mostRequestedScore(requested[i], allocable[i]) nodeScore += resourceScore * weight weightSum += weight } if weightSum == 0 { return 0 } return nodeScore / weightSum } } // The used capacity is calculated on a scale of 0-MaxNodeScore (MaxNodeScore is // constant with value set to 100). // 0 being the lowest priority and 100 being the highest. // The more resources are used the higher the score is. This function // is almost a reversed version of noderesources.leastRequestedScore. func mostRequestedScore(requested, capacity int64) int64 { if capacity == 0 { return 0 } if requested > capacity { // `requested` might be greater than `capacity` because pods with no // requests get minimum values. requested = capacity } return (requested * framework.MaxNodeScore) / capacity }