github.com/pingcap/tiflow@v0.0.0-20240520035814-5bf52d54e205/dm/relay/remote_retry.go (about)

     1  // Copyright 2019 PingCAP, Inc.
     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  // See the License for the specific language governing permissions and
    12  // limitations under the License.
    13  
    14  package relay
    15  
    16  import (
    17  	"context"
    18  	"time"
    19  
    20  	"github.com/pingcap/failpoint"
    21  	"github.com/pingcap/tiflow/dm/pkg/backoff"
    22  	"github.com/pingcap/tiflow/dm/pkg/retry"
    23  	"github.com/pingcap/tiflow/dm/pkg/terror"
    24  )
    25  
    26  // ReaderRetryConfig is the configuration used for binlog reader retry backoff.
    27  // we always enable this now.
    28  type ReaderRetryConfig struct {
    29  	BackoffRollback time.Duration `toml:"backoff-rollback" json:"backoff-rollback"`
    30  	BackoffMax      time.Duration `toml:"backoff-max" json:"backoff-max"`
    31  	// unexposed config
    32  	BackoffMin    time.Duration `json:"-"`
    33  	BackoffJitter bool          `json:"-"`
    34  	BackoffFactor float64       `json:"-"`
    35  }
    36  
    37  // ReaderRetry is used to control the retry for the ReaderRetry.
    38  // It is not thread-safe.
    39  type ReaderRetry struct {
    40  	cfg           ReaderRetryConfig
    41  	bf            *backoff.Backoff
    42  	lastRetryTime time.Time
    43  }
    44  
    45  // NewReaderRetry creates a new ReaderRetry instance.
    46  func NewReaderRetry(cfg ReaderRetryConfig) (*ReaderRetry, error) {
    47  	bf, err := backoff.NewBackoff(cfg.BackoffFactor, cfg.BackoffJitter, cfg.BackoffMin, cfg.BackoffMax)
    48  	if err != nil {
    49  		return nil, terror.WithClass(err, terror.ClassRelayUnit)
    50  	}
    51  	return &ReaderRetry{
    52  		cfg:           cfg,
    53  		bf:            bf,
    54  		lastRetryTime: time.Now(),
    55  	}, nil
    56  }
    57  
    58  // Check checks whether should retry for the error.
    59  func (rr *ReaderRetry) Check(ctx context.Context, err error) bool {
    60  	failpoint.Inject("RelayAllowRetry", func() {
    61  		failpoint.Return(true)
    62  	})
    63  	if !retry.IsConnectionError(err) {
    64  		return false
    65  	}
    66  
    67  	for lrt := rr.lastRetryTime; time.Since(lrt) > rr.cfg.BackoffRollback; lrt = lrt.Add(rr.cfg.BackoffRollback) {
    68  		rr.bf.Rollback()
    69  	}
    70  
    71  	duration := rr.bf.Current()
    72  	select {
    73  	case <-ctx.Done():
    74  		return false
    75  	case <-time.After(duration):
    76  	}
    77  
    78  	rr.lastRetryTime = time.Now()
    79  	rr.bf.BoundaryForward()
    80  	return true
    81  }