From 1e5c432e1029601a664454388ae366ef69618d62 Mon Sep 17 00:00:00 2001 From: Christopher Speller Date: Mon, 25 Jun 2018 12:33:13 -0700 Subject: MM-10702 Moving plugins to use hashicorp go-plugin. (#8978) * Moving plugins to use hashicorp go-plugin. * Tweaks from feedback. --- vendor/google.golang.org/grpc/backoff.go | 96 ++++++++++++++++++++++++++++++++ 1 file changed, 96 insertions(+) create mode 100644 vendor/google.golang.org/grpc/backoff.go (limited to 'vendor/google.golang.org/grpc/backoff.go') diff --git a/vendor/google.golang.org/grpc/backoff.go b/vendor/google.golang.org/grpc/backoff.go new file mode 100644 index 000000000..c40facce5 --- /dev/null +++ b/vendor/google.golang.org/grpc/backoff.go @@ -0,0 +1,96 @@ +/* + * + * Copyright 2017 gRPC 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 grpc + +import ( + "math/rand" + "time" +) + +// DefaultBackoffConfig uses values specified for backoff in +// https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md. +var DefaultBackoffConfig = BackoffConfig{ + MaxDelay: 120 * time.Second, + baseDelay: 1.0 * time.Second, + factor: 1.6, + jitter: 0.2, +} + +// backoffStrategy defines the methodology for backing off after a grpc +// connection failure. +// +// This is unexported until the gRPC project decides whether or not to allow +// alternative backoff strategies. Once a decision is made, this type and its +// method may be exported. +type backoffStrategy interface { + // backoff returns the amount of time to wait before the next retry given + // the number of consecutive failures. + backoff(retries int) time.Duration +} + +// BackoffConfig defines the parameters for the default gRPC backoff strategy. +type BackoffConfig struct { + // MaxDelay is the upper bound of backoff delay. + MaxDelay time.Duration + + // TODO(stevvooe): The following fields are not exported, as allowing + // changes would violate the current gRPC specification for backoff. If + // gRPC decides to allow more interesting backoff strategies, these fields + // may be opened up in the future. + + // baseDelay is the amount of time to wait before retrying after the first + // failure. + baseDelay time.Duration + + // factor is applied to the backoff after each retry. + factor float64 + + // jitter provides a range to randomize backoff delays. + jitter float64 +} + +func setDefaults(bc *BackoffConfig) { + md := bc.MaxDelay + *bc = DefaultBackoffConfig + + if md > 0 { + bc.MaxDelay = md + } +} + +func (bc BackoffConfig) backoff(retries int) time.Duration { + if retries == 0 { + return bc.baseDelay + } + backoff, max := float64(bc.baseDelay), float64(bc.MaxDelay) + for backoff < max && retries > 0 { + backoff *= bc.factor + retries-- + } + if backoff > max { + backoff = max + } + // Randomize backoff delays so that if a cluster of requests start at + // the same time, they won't operate in lockstep. + backoff *= 1 + bc.jitter*(rand.Float64()*2-1) + if backoff < 0 { + return 0 + } + return time.Duration(backoff) +} -- cgit v1.2.3-1-g7c22