github.com/kubewharf/katalyst-core@v0.5.3/pkg/scheduler/plugins/qosawarenoderesources/most_allocated.go (about) 1 /* 2 Copyright 2022 The Katalyst Authors. 3 4 Licensed under the Apache License, Version 2.0 (the "License"); 5 you may not use this file except in compliance with the License. 6 You may obtain a copy of the License at 7 8 http://www.apache.org/licenses/LICENSE-2.0 9 10 Unless required by applicable law or agreed to in writing, software 11 distributed under the License is distributed on an "AS IS" BASIS, 12 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 See the License for the specific language governing permissions and 14 limitations under the License. 15 */ 16 17 package qosawarenoderesources 18 19 import ( 20 "k8s.io/kubernetes/pkg/scheduler/framework" 21 ) 22 23 // mostResourceScorer favors nodes with most requested resources. 24 // It calculates the percentage of memory and CPU requested by pods scheduled on the node, and prioritizes 25 // based on the maximum of the average of the fraction of requested to capacity. 26 // 27 // Details: 28 // (cpu(MaxNodeScore * sum(requested) / capacity) + memory(MaxNodeScore * sum(requested) / capacity)) / weightSum 29 func mostResourceScorer(resToWeightMap resourceToWeightMap) func(requested, allocable resourceToValueMap) int64 { 30 return func(requested, allocatable resourceToValueMap) int64 { 31 var nodeScore, weightSum int64 32 for resource := range requested { 33 weight := resToWeightMap[resource] 34 resourceScore := mostRequestedScore(requested[resource], allocatable[resource]) 35 nodeScore += resourceScore * weight 36 weightSum += weight 37 } 38 if weightSum == 0 { 39 return 0 40 } 41 return nodeScore / weightSum 42 } 43 } 44 45 // The used capacity is calculated on a scale of 0-MaxNodeScore (MaxNodeScore is 46 // constant with value set to 100). 47 // 0 being the lowest priority and 100 being the highest. 48 // The more resources are used the higher the score is. This function 49 // is almost a reversed version of noderesources.leastRequestedScore. 50 func mostRequestedScore(requested, capacity int64) int64 { 51 if capacity == 0 { 52 return 0 53 } 54 if requested > capacity { 55 // `requested` might be greater than `capacity` because pods with no 56 // requests get minimum values. 57 requested = capacity 58 } 59 60 return (requested * framework.MaxNodeScore) / capacity 61 }