mirror of
https://github.com/VictoriaMetrics/VictoriaMetrics.git
synced 2024-12-18 22:52:11 +01:00
145 lines
3.4 KiB
Go
145 lines
3.4 KiB
Go
/*
|
|
*
|
|
* Copyright 2023 Google LLC
|
|
*
|
|
* 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
|
|
*
|
|
* https://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 retry provides a retry helper for talking to S2A gRPC server.
|
|
// The implementation is modeled after
|
|
// https://github.com/googleapis/google-cloud-go/blob/main/compute/metadata/retry.go
|
|
package retry
|
|
|
|
import (
|
|
"context"
|
|
"math/rand"
|
|
"time"
|
|
|
|
"google.golang.org/grpc/grpclog"
|
|
)
|
|
|
|
const (
|
|
maxRetryAttempts = 5
|
|
maxRetryForLoops = 10
|
|
)
|
|
|
|
type defaultBackoff struct {
|
|
max time.Duration
|
|
mul float64
|
|
cur time.Duration
|
|
}
|
|
|
|
// Pause returns a duration, which is used as the backoff wait time
|
|
// before the next retry.
|
|
func (b *defaultBackoff) Pause() time.Duration {
|
|
d := time.Duration(1 + rand.Int63n(int64(b.cur)))
|
|
b.cur = time.Duration(float64(b.cur) * b.mul)
|
|
if b.cur > b.max {
|
|
b.cur = b.max
|
|
}
|
|
return d
|
|
}
|
|
|
|
// Sleep will wait for the specified duration or return on context
|
|
// expiration.
|
|
func Sleep(ctx context.Context, d time.Duration) error {
|
|
t := time.NewTimer(d)
|
|
select {
|
|
case <-ctx.Done():
|
|
t.Stop()
|
|
return ctx.Err()
|
|
case <-t.C:
|
|
return nil
|
|
}
|
|
}
|
|
|
|
// NewRetryer creates an instance of S2ARetryer using the defaultBackoff
|
|
// implementation.
|
|
var NewRetryer = func() *S2ARetryer {
|
|
return &S2ARetryer{bo: &defaultBackoff{
|
|
cur: 100 * time.Millisecond,
|
|
max: 30 * time.Second,
|
|
mul: 2,
|
|
}}
|
|
}
|
|
|
|
type backoff interface {
|
|
Pause() time.Duration
|
|
}
|
|
|
|
// S2ARetryer implements a retry helper for talking to S2A gRPC server.
|
|
type S2ARetryer struct {
|
|
bo backoff
|
|
attempts int
|
|
}
|
|
|
|
// Attempts return the number of retries attempted.
|
|
func (r *S2ARetryer) Attempts() int {
|
|
return r.attempts
|
|
}
|
|
|
|
// Retry returns a boolean indicating whether retry should be performed
|
|
// and the backoff duration.
|
|
func (r *S2ARetryer) Retry(err error) (time.Duration, bool) {
|
|
if err == nil {
|
|
return 0, false
|
|
}
|
|
if r.attempts >= maxRetryAttempts {
|
|
return 0, false
|
|
}
|
|
r.attempts++
|
|
return r.bo.Pause(), true
|
|
}
|
|
|
|
// Run uses S2ARetryer to execute the function passed in, until success or reaching
|
|
// max number of retry attempts.
|
|
func Run(ctx context.Context, f func() error) {
|
|
retryer := NewRetryer()
|
|
forLoopCnt := 0
|
|
var err error
|
|
for {
|
|
err = f()
|
|
if bo, shouldRetry := retryer.Retry(err); shouldRetry {
|
|
if grpclog.V(1) {
|
|
grpclog.Infof("will attempt retry: %v", err)
|
|
}
|
|
if ctx.Err() != nil {
|
|
if grpclog.V(1) {
|
|
grpclog.Infof("exit retry loop due to context error: %v", ctx.Err())
|
|
}
|
|
break
|
|
}
|
|
if errSleep := Sleep(ctx, bo); errSleep != nil {
|
|
if grpclog.V(1) {
|
|
grpclog.Infof("exit retry loop due to sleep error: %v", errSleep)
|
|
}
|
|
break
|
|
}
|
|
// This shouldn't happen, just make sure we are not stuck in the for loops.
|
|
forLoopCnt++
|
|
if forLoopCnt > maxRetryForLoops {
|
|
if grpclog.V(1) {
|
|
grpclog.Infof("exit the for loop after too many retries")
|
|
}
|
|
break
|
|
}
|
|
continue
|
|
}
|
|
if grpclog.V(1) {
|
|
grpclog.Infof("retry conditions not met, exit the loop")
|
|
}
|
|
break
|
|
}
|
|
}
|