1 // Copyright 2018 The etcd Authors 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 package clientv3 16 17 import ( 18 "math/rand" 19 "time" 20 ) 21 22 // jitterUp adds random jitter to the duration. 23 // 24 // This adds or subtracts time from the duration within a given jitter fraction. 25 // For example for 10s and jitter 0.1, it will return a time within [9s, 11s]) 26 // 27 // Reference: https://godoc.org/github.com/grpc-ecosystem/go-grpc-middleware/util/backoffutils 28 func jitterUp(duration time.Duration, jitter float64) time.Duration { 29 multiplier := jitter * (rand.Float64()*2 - 1) 30 return time.Duration(float64(duration) * (1 + multiplier)) 31 } 32