go.uber.org/cadence@v1.2.9/internal/common/autoscaler/recommender.go (about) 1 // Copyright (c) 2017-2021 Uber Technologies Inc. 2 // 3 // Permission is hereby granted, free of charge, to any person obtaining a copy 4 // of this software and associated documentation files (the "Software"), to deal 5 // in the Software without restriction, including without limitation the rights 6 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 7 // copies of the Software, and to permit persons to whom the Software is 8 // furnished to do so, subject to the following conditions: 9 // 10 // The above copyright notice and this permission notice shall be included in 11 // all copies or substantial portions of the Software. 12 // 13 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 14 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 15 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 16 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 17 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 18 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 19 // THE SOFTWARE. 20 21 package autoscaler 22 23 import "math" 24 25 // Recommender a recommendation generator for ResourceUnit 26 type Recommender interface { 27 Recommend(currentResource ResourceUnit, currentUsages Usages) ResourceUnit 28 } 29 30 type linearRecommender struct { 31 lower, upper ResourceUnit 32 targetUsages Usages 33 } 34 35 // NewLinearRecommender create a linear Recommender 36 func NewLinearRecommender(lower, upper ResourceUnit, targetUsages Usages) Recommender { 37 return &linearRecommender{ 38 lower: lower, 39 upper: upper, 40 targetUsages: targetUsages, 41 } 42 } 43 44 // Recommend recommends the new value 45 func (l *linearRecommender) Recommend(currentResource ResourceUnit, currentUsages Usages) ResourceUnit { 46 var recommend float64 47 48 // average recommendation over all UsageType 49 for usageType := range currentUsages { 50 var r float64 51 if l.targetUsages[usageType] == 0 { // avoid division by zero 52 r = math.MaxFloat64 53 } else { 54 if currentUsages[usageType].Value() == float64(1000) { 55 r = l.upper.Value() 56 } else { 57 r = currentResource.Value() * currentUsages[usageType].Value() / l.targetUsages[usageType].Value() 58 } 59 } 60 // boundary check 61 r = math.Min(l.upper.Value(), math.Max(l.lower.Value(), r)) 62 recommend += r 63 } 64 recommend /= float64(len(currentUsages)) 65 return ResourceUnit(recommend) 66 }