diff --git a/internal/retry/backoff.go b/config/retry/backoff.go
similarity index 100%
rename from internal/retry/backoff.go
rename to config/retry/backoff.go
diff --git a/internal/retry/backoff_test.go b/config/retry/backoff_test.go
similarity index 100%
rename from internal/retry/backoff_test.go
rename to config/retry/backoff_test.go
diff --git a/config/retry/config.go b/config/retry/config.go
new file mode 100644
index 00000000..89a9bc38
--- /dev/null
+++ b/config/retry/config.go
@@ -0,0 +1,207 @@
+// Copyright 2021 TiKV 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.
+
+// NOTE: The code in this file is based on code from the
+// TiDB project, licensed under the Apache License v 2.0
+//
+// https://github.com/pingcap/tidb/tree/cc5e161ac06827589c4966674597c137cc9e809c/store/tikv/retry/config.go
+//
+
+// Copyright 2021 PingCAP, Inc.
+//
+// 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 retry
+
+import (
+	"context"
+	"math"
+	"math/rand"
+	"strings"
+	"time"
+
+	"github.com/prometheus/client_golang/prometheus"
+	tikverr "github.com/tikv/client-go/v2/error"
+	"github.com/tikv/client-go/v2/internal/logutil"
+	"github.com/tikv/client-go/v2/kv"
+	"github.com/tikv/client-go/v2/metrics"
+	"go.uber.org/zap"
+)
+
+// Config is the configuration of the Backoff function.
+type Config struct {
+	name   string
+	metric *prometheus.Observer
+	fnCfg  *BackoffFnCfg
+	err    error
+}
+
+// backoffFn is the backoff function which compute the sleep time and do sleep.
+type backoffFn func(ctx context.Context, maxSleepMs int) int
+
+func (c *Config) createBackoffFn(vars *kv.Variables) backoffFn {
+	if strings.EqualFold(c.name, txnLockFastName) {
+		return newBackoffFn(vars.BackoffLockFast, c.fnCfg.cap, c.fnCfg.jitter)
+	}
+	return newBackoffFn(c.fnCfg.base, c.fnCfg.cap, c.fnCfg.jitter)
+}
+
+// BackoffFnCfg is the configuration for the backoff func which implements exponential backoff with
+// optional jitters.
+// See http://www.awsarchitectureblog.com/2015/03/backoff.html
+type BackoffFnCfg struct {
+	base   int
+	cap    int
+	jitter int
+}
+
+// NewBackoffFnCfg creates the config for BackoffFn.
+func NewBackoffFnCfg(base, cap, jitter int) *BackoffFnCfg {
+	return &BackoffFnCfg{
+		base,
+		cap,
+		jitter,
+	}
+}
+
+// NewConfig creates a new Config for the Backoff operation.
+func NewConfig(name string, metric *prometheus.Observer, backoffFnCfg *BackoffFnCfg, err error) *Config {
+	return &Config{
+		name:   name,
+		metric: metric,
+		fnCfg:  backoffFnCfg,
+		err:    err,
+	}
+}
+
+func (c *Config) String() string {
+	return c.name
+}
+
+// SetErrors sets a more detailed error instead of the default bo config.
+func (c *Config) SetErrors(err error) {
+	c.err = err
+}
+
+func (c *Config) SetBackoffFnCfg(fnCfg *BackoffFnCfg) {
+	c.fnCfg = fnCfg
+}
+
+const txnLockFastName = "txnLockFast"
+
+// Backoff Config variables.
+var (
+	// TODO: distinguish tikv and tiflash in metrics
+	BoTiKVRPC    = NewConfig("tikvRPC", &metrics.BackoffHistogramRPC, NewBackoffFnCfg(100, 2000, EqualJitter), tikverr.ErrTiKVServerTimeout)
+	BoTiFlashRPC = NewConfig("tiflashRPC", &metrics.BackoffHistogramRPC, NewBackoffFnCfg(100, 2000, EqualJitter), tikverr.ErrTiFlashServerTimeout)
+	BoTxnLock    = NewConfig("txnLock", &metrics.BackoffHistogramLock, NewBackoffFnCfg(100, 3000, EqualJitter), tikverr.ErrResolveLockTimeout)
+	BoPDRPC      = NewConfig("pdRPC", &metrics.BackoffHistogramPD, NewBackoffFnCfg(500, 3000, EqualJitter), tikverr.NewErrPDServerTimeout(""))
+	// change base time to 2ms, because it may recover soon.
+	BoRegionMiss               = NewConfig("regionMiss", &metrics.BackoffHistogramRegionMiss, NewBackoffFnCfg(2, 500, NoJitter), tikverr.ErrRegionUnavailable)
+	BoRegionScheduling         = NewConfig("regionScheduling", &metrics.BackoffHistogramRegionScheduling, NewBackoffFnCfg(2, 500, NoJitter), tikverr.ErrRegionUnavailable)
+	BoTiKVServerBusy           = NewConfig("tikvServerBusy", &metrics.BackoffHistogramServerBusy, NewBackoffFnCfg(2000, 10000, EqualJitter), tikverr.ErrTiKVServerBusy)
+	BoTiKVDiskFull             = NewConfig("tikvDiskFull", &metrics.BackoffHistogramTiKVDiskFull, NewBackoffFnCfg(500, 5000, NoJitter), tikverr.ErrTiKVDiskFull)
+	BoRegionRecoveryInProgress = NewConfig("regionRecoveryInProgress", &metrics.BackoffHistogramRegionRecoveryInProgress, NewBackoffFnCfg(100, 10000, EqualJitter), tikverr.ErrRegionRecoveryInProgress)
+	BoTiFlashServerBusy        = NewConfig("tiflashServerBusy", &metrics.BackoffHistogramServerBusy, NewBackoffFnCfg(2000, 10000, EqualJitter), tikverr.ErrTiFlashServerBusy)
+	BoTxnNotFound              = NewConfig("txnNotFound", &metrics.BackoffHistogramEmpty, NewBackoffFnCfg(2, 500, NoJitter), tikverr.ErrResolveLockTimeout)
+	BoStaleCmd                 = NewConfig("staleCommand", &metrics.BackoffHistogramStaleCmd, NewBackoffFnCfg(2, 1000, NoJitter), tikverr.ErrTiKVStaleCommand)
+	BoMaxTsNotSynced           = NewConfig("maxTsNotSynced", &metrics.BackoffHistogramEmpty, NewBackoffFnCfg(2, 500, NoJitter), tikverr.ErrTiKVMaxTimestampNotSynced)
+	BoMaxDataNotReady          = NewConfig("dataNotReady", &metrics.BackoffHistogramDataNotReady, NewBackoffFnCfg(2, 2000, NoJitter), tikverr.ErrRegionDataNotReady)
+	BoMaxRegionNotInitialized  = NewConfig("regionNotInitialized", &metrics.BackoffHistogramEmpty, NewBackoffFnCfg(2, 1000, NoJitter), tikverr.ErrRegionNotInitialized)
+	BoIsWitness                = NewConfig("isWitness", &metrics.BackoffHistogramIsWitness, NewBackoffFnCfg(1000, 10000, EqualJitter), tikverr.ErrIsWitness)
+	// TxnLockFast's `base` load from vars.BackoffLockFast when create BackoffFn.
+	BoTxnLockFast = NewConfig(txnLockFastName, &metrics.BackoffHistogramLockFast, NewBackoffFnCfg(2, 3000, EqualJitter), tikverr.ErrResolveLockTimeout)
+)
+
+var isSleepExcluded = map[string]int{
+	BoTiKVServerBusy.name: 600000, // The max excluded limit is 10min.
+	// add BoTiFlashServerBusy if appropriate
+}
+
+// setBackoffExcluded is used for test only.
+func setBackoffExcluded(name string, maxVal int) {
+	if _, ok := isSleepExcluded[name]; ok {
+		isSleepExcluded[name] = maxVal
+	}
+}
+
+const (
+	// NoJitter makes the backoff sequence strict exponential.
+	NoJitter = 1 + iota
+	// FullJitter applies random factors to strict exponential.
+	FullJitter
+	// EqualJitter is also randomized, but prevents very short sleeps.
+	EqualJitter
+	// DecorrJitter increases the maximum jitter based on the last random value.
+	DecorrJitter
+)
+
+// newBackoffFn creates a backoff func which implements exponential backoff with
+// optional jitters.
+// See http://www.awsarchitectureblog.com/2015/03/backoff.html
+func newBackoffFn(base, cap, jitter int) backoffFn {
+	if base < 2 {
+		// Top prevent panic in 'rand.Intn'.
+		base = 2
+	}
+	attempts := 0
+	lastSleep := base
+	return func(ctx context.Context, maxSleepMs int) int {
+		var sleep int
+		switch jitter {
+		case NoJitter:
+			sleep = expo(base, cap, attempts)
+		case FullJitter:
+			v := expo(base, cap, attempts)
+			sleep = rand.Intn(v)
+		case EqualJitter:
+			v := expo(base, cap, attempts)
+			sleep = v/2 + rand.Intn(v/2)
+		case DecorrJitter:
+			sleep = int(math.Min(float64(cap), float64(base+rand.Intn(lastSleep*3-base))))
+		}
+		logutil.BgLogger().Debug("backoff",
+			zap.Int("base", base),
+			zap.Int("sleep", sleep),
+			zap.Int("attempts", attempts))
+
+		realSleep := sleep
+		// when set maxSleepMs >= 0 in `tikv.BackoffWithMaxSleep` will force sleep maxSleepMs milliseconds.
+		if maxSleepMs >= 0 && realSleep > maxSleepMs {
+			realSleep = maxSleepMs
+		}
+		select {
+		case <-time.After(time.Duration(realSleep) * time.Millisecond):
+			attempts++
+			lastSleep = sleep
+			return realSleep
+		case <-ctx.Done():
+			return 0
+		}
+	}
+}
+
+func expo(base, cap, n int) int {
+	return int(math.Min(float64(cap), float64(base)*math.Pow(2.0, float64(n))))
+}
diff --git a/internal/retry/main_test.go b/config/retry/main_test.go
similarity index 100%
rename from internal/retry/main_test.go
rename to config/retry/main_test.go
diff --git a/internal/client/client_batch.go b/internal/client/client_batch.go
index 49b8fe04..9802350b 100644
--- a/internal/client/client_batch.go
+++ b/internal/client/client_batch.go
@@ -48,9 +48,9 @@ import (
 	"github.com/pkg/errors"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/tikv/client-go/v2/config"
+	"github.com/tikv/client-go/v2/config/retry"
 	tikverr "github.com/tikv/client-go/v2/error"
 	"github.com/tikv/client-go/v2/internal/logutil"
-	"github.com/tikv/client-go/v2/internal/retry"
 	"github.com/tikv/client-go/v2/metrics"
 	"github.com/tikv/client-go/v2/tikvrpc"
 	"github.com/tikv/client-go/v2/util"
diff --git a/internal/client/main_test.go b/internal/client/main_test.go
index 6a22714f..2e031f98 100644
--- a/internal/client/main_test.go
+++ b/internal/client/main_test.go
@@ -25,8 +25,8 @@ func TestMain(m *testing.M) {
 	util.EnableFailpoints()
 	opts := []goleak.Option{
 		goleak.IgnoreTopFunction("google.golang.org/grpc.(*ClientConn).WaitForStateChange"),
-		goleak.IgnoreTopFunction("github.com/tikv/client-go/v2/internal/retry.newBackoffFn.func1"),
-		goleak.IgnoreTopFunction("github.com/tikv/client-go/v2/internal/retry.(*Config).createBackoffFn.newBackoffFn.func2"),
+		goleak.IgnoreTopFunction("github.com/tikv/client-go/v2/config/retry.newBackoffFn.func1"),
+		goleak.IgnoreTopFunction("github.com/tikv/client-go/v2/config/retry.(*Config).createBackoffFn.newBackoffFn.func2"),
 	}
 	goleak.VerifyTestMain(m, opts...)
 }
diff --git a/internal/client/retry/backoff.go b/internal/client/retry/backoff.go
new file mode 100644
index 00000000..a2723e05
--- /dev/null
+++ b/internal/client/retry/backoff.go
@@ -0,0 +1,384 @@
+// Copyright 2021 TiKV 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.
+
+// NOTE: The code in this file is based on code from the
+// TiDB project, licensed under the Apache License v 2.0
+//
+// https://github.com/pingcap/tidb/tree/cc5e161ac06827589c4966674597c137cc9e809c/store/tikv/retry/backoff.go
+//
+
+// Copyright 2016 PingCAP, Inc.
+//
+// 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 retry
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"math"
+	"strconv"
+	"strings"
+	"sync/atomic"
+	"time"
+
+	"github.com/opentracing/opentracing-go"
+	"github.com/pingcap/log"
+	"github.com/pkg/errors"
+	tikverr "github.com/tikv/client-go/v2/error"
+	"github.com/tikv/client-go/v2/internal/logutil"
+	"github.com/tikv/client-go/v2/kv"
+	"github.com/tikv/client-go/v2/util"
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+)
+
+// Backoffer is a utility for retrying queries.
+type Backoffer struct {
+	ctx context.Context
+
+	fn            map[string]backoffFn
+	maxSleep      int
+	totalSleep    int
+	excludedSleep int
+
+	vars *kv.Variables
+	noop bool
+
+	errors         []error
+	configs        []*Config
+	backoffSleepMS map[string]int
+	backoffTimes   map[string]int
+	parent         *Backoffer
+}
+
+type txnStartCtxKeyType struct{}
+
+// TxnStartKey is a key for transaction start_ts info in context.Context.
+var TxnStartKey interface{} = txnStartCtxKeyType{}
+
+// NewBackoffer (Deprecated) creates a Backoffer with maximum sleep time(in ms).
+func NewBackoffer(ctx context.Context, maxSleep int) *Backoffer {
+	return &Backoffer{
+		ctx:      ctx,
+		maxSleep: maxSleep,
+		vars:     kv.DefaultVars,
+	}
+}
+
+// NewBackofferWithVars creates a Backoffer with maximum sleep time(in ms) and kv.Variables.
+func NewBackofferWithVars(ctx context.Context, maxSleep int, vars *kv.Variables) *Backoffer {
+	return NewBackoffer(ctx, maxSleep).withVars(vars)
+}
+
+// NewNoopBackoff create a Backoffer do nothing just return error directly
+func NewNoopBackoff(ctx context.Context) *Backoffer {
+	return &Backoffer{ctx: ctx, noop: true}
+}
+
+// withVars sets the kv.Variables to the Backoffer and return it.
+func (b *Backoffer) withVars(vars *kv.Variables) *Backoffer {
+	if vars != nil {
+		b.vars = vars
+	}
+	// maxSleep is the max sleep time in millisecond.
+	// When it is multiplied by BackOffWeight, it should not be greater than MaxInt32.
+	if b.maxSleep > 0 && math.MaxInt32/b.vars.BackOffWeight >= b.maxSleep {
+		b.maxSleep *= b.vars.BackOffWeight
+	}
+	return b
+}
+
+// Backoff sleeps a while base on the Config and records the error message.
+// It returns a retryable error if total sleep time exceeds maxSleep.
+func (b *Backoffer) Backoff(cfg *Config, err error) error {
+	if span := opentracing.SpanFromContext(b.ctx); span != nil && span.Tracer() != nil {
+		span1 := span.Tracer().StartSpan(fmt.Sprintf("tikv.backoff.%s", cfg), opentracing.ChildOf(span.Context()))
+		defer span1.Finish()
+		opentracing.ContextWithSpan(b.ctx, span1)
+	}
+	return b.BackoffWithCfgAndMaxSleep(cfg, -1, err)
+}
+
+// BackoffWithMaxSleepTxnLockFast sleeps a while base on the MaxSleepTxnLock and records the error message
+// and never sleep more than maxSleepMs for each sleep.
+func (b *Backoffer) BackoffWithMaxSleepTxnLockFast(maxSleepMs int, err error) error {
+	cfg := BoTxnLockFast
+	return b.BackoffWithCfgAndMaxSleep(cfg, maxSleepMs, err)
+}
+
+// BackoffWithCfgAndMaxSleep sleeps a while base on the Config and records the error message
+// and never sleep more than maxSleepMs for each sleep.
+func (b *Backoffer) BackoffWithCfgAndMaxSleep(cfg *Config, maxSleepMs int, err error) error {
+	if strings.Contains(err.Error(), tikverr.MismatchClusterID) {
+		logutil.Logger(b.ctx).Fatal("critical error", zap.Error(err))
+	}
+	select {
+	case <-b.ctx.Done():
+		return errors.WithStack(err)
+	default:
+	}
+	if b.noop {
+		return err
+	}
+	maxBackoffTimeExceeded := (b.totalSleep - b.excludedSleep) >= b.maxSleep
+	maxExcludedTimeExceeded := false
+	if maxLimit, ok := isSleepExcluded[cfg.name]; ok {
+		maxExcludedTimeExceeded = b.excludedSleep >= maxLimit && b.excludedSleep >= b.maxSleep
+	}
+	maxTimeExceeded := maxBackoffTimeExceeded || maxExcludedTimeExceeded
+	if b.maxSleep > 0 && maxTimeExceeded {
+		longestSleepCfg, longestSleepTime := b.longestSleepCfg()
+		errMsg := fmt.Sprintf("%s backoffer.maxSleep %dms is exceeded, errors:", cfg.String(), b.maxSleep)
+		for i, err := range b.errors {
+			// Print only last 3 errors for non-DEBUG log levels.
+			if log.GetLevel() == zapcore.DebugLevel || i >= len(b.errors)-3 {
+				errMsg += "\n" + err.Error()
+			}
+		}
+		var backoffDetail bytes.Buffer
+		totalTimes := 0
+		for name, times := range b.backoffTimes {
+			totalTimes += times
+			if backoffDetail.Len() > 0 {
+				backoffDetail.WriteString(", ")
+			}
+			backoffDetail.WriteString(name)
+			backoffDetail.WriteString(":")
+			backoffDetail.WriteString(strconv.Itoa(times))
+		}
+		errMsg += fmt.Sprintf("\ntotal-backoff-times: %v, backoff-detail: %v, maxBackoffTimeExceeded: %v, maxExcludedTimeExceeded: %v",
+			totalTimes, backoffDetail.String(), maxBackoffTimeExceeded, maxExcludedTimeExceeded)
+		returnedErr := err
+		if longestSleepCfg != nil {
+			errMsg += fmt.Sprintf("\nlongest sleep type: %s, time: %dms", longestSleepCfg.String(), longestSleepTime)
+			returnedErr = longestSleepCfg.err
+		}
+		logutil.Logger(b.ctx).Warn(errMsg)
+		// Use the backoff type that contributes most to the timeout to generate a MySQL error.
+		return errors.WithStack(returnedErr)
+	}
+	b.errors = append(b.errors, errors.Errorf("%s at %s", err.Error(), time.Now().Format(time.RFC3339Nano)))
+	b.configs = append(b.configs, cfg)
+
+	// Lazy initialize.
+	if b.fn == nil {
+		b.fn = make(map[string]backoffFn)
+	}
+	f, ok := b.fn[cfg.name]
+	if !ok {
+		f = cfg.createBackoffFn(b.vars)
+		b.fn[cfg.name] = f
+	}
+	realSleep := f(b.ctx, maxSleepMs)
+	if cfg.metric != nil {
+		(*cfg.metric).Observe(float64(realSleep) / 1000)
+	}
+
+	b.totalSleep += realSleep
+	if _, ok := isSleepExcluded[cfg.name]; ok {
+		b.excludedSleep += realSleep
+	}
+	if b.backoffSleepMS == nil {
+		b.backoffSleepMS = make(map[string]int)
+	}
+	b.backoffSleepMS[cfg.name] += realSleep
+	if b.backoffTimes == nil {
+		b.backoffTimes = make(map[string]int)
+	}
+	b.backoffTimes[cfg.name]++
+
+	stmtExec := b.ctx.Value(util.ExecDetailsKey)
+	if stmtExec != nil {
+		detail := stmtExec.(*util.ExecDetails)
+		atomic.AddInt64(&detail.BackoffDuration, int64(realSleep)*int64(time.Millisecond))
+		atomic.AddInt64(&detail.BackoffCount, 1)
+	}
+
+	if b.vars != nil && b.vars.Killed != nil {
+		if atomic.LoadUint32(b.vars.Killed) == 1 {
+			return errors.WithStack(tikverr.ErrQueryInterrupted)
+		}
+	}
+
+	var startTs interface{}
+	if ts := b.ctx.Value(TxnStartKey); ts != nil {
+		startTs = ts
+	}
+	logutil.Logger(b.ctx).Debug("retry later",
+		zap.Error(err),
+		zap.Int("totalSleep", b.totalSleep),
+		zap.Int("excludedSleep", b.excludedSleep),
+		zap.Int("maxSleep", b.maxSleep),
+		zap.Stringer("type", cfg),
+		zap.Reflect("txnStartTS", startTs))
+	return nil
+}
+
+func (b *Backoffer) String() string {
+	if b.totalSleep == 0 {
+		return ""
+	}
+	return fmt.Sprintf(" backoff(%dms %v)", b.totalSleep, b.configs)
+}
+
+// copyMapWithoutRecursive is only used to deep copy map fields in the Backoffer type.
+func copyMapWithoutRecursive(srcMap map[string]int) map[string]int {
+	result := map[string]int{}
+	for k, v := range srcMap {
+		result[k] = v
+	}
+	return result
+}
+
+// Clone creates a new Backoffer which keeps current Backoffer's sleep time and errors, and shares
+// current Backoffer's context.
+// Some fields like `configs` and `vars` are concurrently used by all the backoffers in different threads,
+// try not to modify the referenced content directly.
+func (b *Backoffer) Clone() *Backoffer {
+	return &Backoffer{
+		ctx:            b.ctx,
+		maxSleep:       b.maxSleep,
+		totalSleep:     b.totalSleep,
+		excludedSleep:  b.excludedSleep,
+		vars:           b.vars,
+		errors:         append([]error{}, b.errors...),
+		configs:        append([]*Config{}, b.configs...),
+		backoffSleepMS: copyMapWithoutRecursive(b.backoffSleepMS),
+		backoffTimes:   copyMapWithoutRecursive(b.backoffTimes),
+		parent:         b.parent,
+	}
+}
+
+// Fork creates a new Backoffer which keeps current Backoffer's sleep time and errors, and holds
+// a child context of current Backoffer's context.
+// Some fields like `configs` and `vars` are concurrently used by all the backoffers in different threads,
+// try not to modify the referenced content directly.
+func (b *Backoffer) Fork() (*Backoffer, context.CancelFunc) {
+	ctx, cancel := context.WithCancel(b.ctx)
+	return &Backoffer{
+		ctx:            ctx,
+		maxSleep:       b.maxSleep,
+		totalSleep:     b.totalSleep,
+		excludedSleep:  b.excludedSleep,
+		errors:         append([]error{}, b.errors...),
+		configs:        append([]*Config{}, b.configs...),
+		backoffSleepMS: copyMapWithoutRecursive(b.backoffSleepMS),
+		backoffTimes:   copyMapWithoutRecursive(b.backoffTimes),
+		vars:           b.vars,
+		parent:         b,
+	}, cancel
+}
+
+// GetVars returns the binded vars.
+func (b *Backoffer) GetVars() *kv.Variables {
+	return b.vars
+}
+
+// GetTotalSleep returns total sleep time.
+func (b *Backoffer) GetTotalSleep() int {
+	return b.totalSleep
+}
+
+// GetTypes returns type list of this backoff and all its ancestors.
+func (b *Backoffer) GetTypes() []string {
+	typs := make([]string, 0, len(b.configs))
+	for b != nil {
+		for _, cfg := range b.configs {
+			typs = append(typs, cfg.String())
+		}
+		b = b.parent
+	}
+	return typs
+}
+
+// GetCtx returns the binded context.
+func (b *Backoffer) GetCtx() context.Context {
+	return b.ctx
+}
+
+// SetCtx sets the binded context to ctx.
+func (b *Backoffer) SetCtx(ctx context.Context) {
+	b.ctx = ctx
+}
+
+// GetBackoffTimes returns a map contains backoff time count by type.
+func (b *Backoffer) GetBackoffTimes() map[string]int {
+	return b.backoffTimes
+}
+
+// GetTotalBackoffTimes returns the total backoff times of the backoffer.
+func (b *Backoffer) GetTotalBackoffTimes() int {
+	total := 0
+	for _, time := range b.backoffTimes {
+		total += time
+	}
+	return total
+}
+
+// GetBackoffSleepMS returns a map contains backoff sleep time by type.
+func (b *Backoffer) GetBackoffSleepMS() map[string]int {
+	return b.backoffSleepMS
+}
+
+// ErrorsNum returns the number of errors.
+func (b *Backoffer) ErrorsNum() int {
+	return len(b.errors)
+}
+
+// Reset resets the sleep state of the backoffer, so that following backoff
+// can sleep shorter. The reason why we don't create a new backoffer is that
+// backoffer is similar to context and it records some metrics that we
+// want to record for an entire process which is composed of serveral stages.
+func (b *Backoffer) Reset() {
+	b.fn = nil
+	b.totalSleep = 0
+	b.excludedSleep = 0
+}
+
+// ResetMaxSleep resets the sleep state and max sleep limit of the backoffer.
+// It's used when switches to the next stage of the process.
+func (b *Backoffer) ResetMaxSleep(maxSleep int) {
+	b.Reset()
+	b.maxSleep = maxSleep
+	b.withVars(b.vars)
+}
+
+func (b *Backoffer) longestSleepCfg() (*Config, int) {
+	candidate := ""
+	maxSleep := 0
+	for cfgName, sleepTime := range b.backoffSleepMS {
+		if _, ok := isSleepExcluded[cfgName]; sleepTime > maxSleep && !ok {
+			maxSleep = sleepTime
+			candidate = cfgName
+		}
+	}
+	for _, cfg := range b.configs {
+		if cfg.name == candidate {
+			return cfg, maxSleep
+		}
+	}
+	return nil, 0
+}
diff --git a/internal/client/retry/backoff_test.go b/internal/client/retry/backoff_test.go
new file mode 100644
index 00000000..cdd6b46f
--- /dev/null
+++ b/internal/client/retry/backoff_test.go
@@ -0,0 +1,112 @@
+// Copyright 2021 TiKV 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.
+
+// NOTE: The code in this file is based on code from the
+// TiDB project, licensed under the Apache License v 2.0
+//
+// https://github.com/pingcap/tidb/tree/cc5e161ac06827589c4966674597c137cc9e809c/store/tikv/retry/backoff_test.go
+//
+
+// Copyright 2019 PingCAP, Inc.
+//
+// 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 retry
+
+import (
+	"context"
+	"errors"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestBackoffWithMax(t *testing.T) {
+	b := NewBackofferWithVars(context.TODO(), 2000, nil)
+	err := b.BackoffWithMaxSleepTxnLockFast(5, errors.New("test"))
+
+	assert.Nil(t, err)
+	assert.Equal(t, 5, b.totalSleep)
+}
+
+func TestBackoffErrorType(t *testing.T) {
+	// the actual maxSleep is multiplied by weight, which is 1600ms
+	b := NewBackofferWithVars(context.TODO(), 800, nil)
+	err := b.Backoff(BoRegionMiss, errors.New("region miss")) // 2ms sleep
+	assert.Nil(t, err)
+	// 6ms sleep at most in total
+	for i := 0; i < 2; i++ {
+		err = b.Backoff(BoMaxDataNotReady, errors.New("data not ready"))
+		assert.Nil(t, err)
+	}
+	// 100ms sleep at most in total
+	err = b.Backoff(BoRegionRecoveryInProgress, errors.New("recovery in progress"))
+	assert.Nil(t, err)
+
+	// sleep from ServerIsBusy is not counted
+	err = b.Backoff(BoTiKVServerBusy, errors.New("server is busy"))
+	assert.Nil(t, err)
+	// 1000ms sleep at most in total
+	err = b.Backoff(BoIsWitness, errors.New("peer is witness"))
+	assert.Nil(t, err)
+	// wait it exceed max sleep
+	for i := 0; i < 15; i++ {
+		err = b.Backoff(BoTxnNotFound, errors.New("txn not found"))
+		if err != nil {
+			// Next backoff should return error of backoff that sleeps for longest time.
+			assert.ErrorIs(t, err, BoTxnNotFound.err)
+			return
+		}
+	}
+	assert.Fail(t, "should not be here")
+}
+
+func TestBackoffDeepCopy(t *testing.T) {
+	var err error
+	b := NewBackofferWithVars(context.TODO(), 4, nil)
+	// 700 ms sleep in total and the backoffer will return an error next time.
+	for i := 0; i < 3; i++ {
+		err = b.Backoff(BoMaxDataNotReady, errors.New("data not ready"))
+		assert.Nil(t, err)
+	}
+	bForked, cancel := b.Fork()
+	defer cancel()
+	bCloned := b.Clone()
+	for _, b := range []*Backoffer{bForked, bCloned} {
+		err = b.Backoff(BoTiKVRPC, errors.New("tikv rpc"))
+		assert.ErrorIs(t, err, BoMaxDataNotReady.err)
+	}
+}
+
+func TestBackoffWithMaxExcludedExceed(t *testing.T) {
+	setBackoffExcluded(BoTiKVServerBusy.name, 1)
+	b := NewBackofferWithVars(context.TODO(), 1, nil)
+	err := b.Backoff(BoTiKVServerBusy, errors.New("server is busy"))
+	assert.Nil(t, err)
+
+	// As the total excluded sleep is greater than the max limited value, error should be returned.
+	err = b.Backoff(BoTiKVServerBusy, errors.New("server is busy"))
+	assert.NotNil(t, err)
+	assert.Greater(t, b.excludedSleep, b.maxSleep)
+}
diff --git a/internal/retry/config.go b/internal/client/retry/config.go
similarity index 100%
rename from internal/retry/config.go
rename to internal/client/retry/config.go
diff --git a/internal/locate/region_cache.go b/internal/locate/region_cache.go
index 96e1ac88..f548f13d 100644
--- a/internal/locate/region_cache.go
+++ b/internal/locate/region_cache.go
@@ -55,11 +55,11 @@ import (
 	"github.com/pingcap/kvproto/pkg/metapb"
 	"github.com/pkg/errors"
 	"github.com/tikv/client-go/v2/config"
+	"github.com/tikv/client-go/v2/config/retry"
 	tikverr "github.com/tikv/client-go/v2/error"
 	"github.com/tikv/client-go/v2/internal/apicodec"
 	"github.com/tikv/client-go/v2/internal/client"
 	"github.com/tikv/client-go/v2/internal/logutil"
-	"github.com/tikv/client-go/v2/internal/retry"
 	"github.com/tikv/client-go/v2/kv"
 	"github.com/tikv/client-go/v2/metrics"
 	"github.com/tikv/client-go/v2/tikvrpc"
diff --git a/internal/locate/region_cache_test.go b/internal/locate/region_cache_test.go
index c4c8cbb5..54718096 100644
--- a/internal/locate/region_cache_test.go
+++ b/internal/locate/region_cache_test.go
@@ -50,9 +50,9 @@ import (
 	"github.com/pingcap/kvproto/pkg/errorpb"
 	"github.com/pingcap/kvproto/pkg/metapb"
 	"github.com/stretchr/testify/suite"
+	"github.com/tikv/client-go/v2/config/retry"
 	"github.com/tikv/client-go/v2/internal/apicodec"
 	"github.com/tikv/client-go/v2/internal/mockstore/mocktikv"
-	"github.com/tikv/client-go/v2/internal/retry"
 	"github.com/tikv/client-go/v2/kv"
 	pd "github.com/tikv/pd/client"
 )
diff --git a/internal/locate/region_request.go b/internal/locate/region_request.go
index a83b93dc..b8e2dede 100644
--- a/internal/locate/region_request.go
+++ b/internal/locate/region_request.go
@@ -56,10 +56,10 @@ import (
 	"github.com/pingcap/kvproto/pkg/kvrpcpb"
 	"github.com/pingcap/kvproto/pkg/metapb"
 	"github.com/pkg/errors"
+	"github.com/tikv/client-go/v2/config/retry"
 	tikverr "github.com/tikv/client-go/v2/error"
 	"github.com/tikv/client-go/v2/internal/client"
 	"github.com/tikv/client-go/v2/internal/logutil"
-	"github.com/tikv/client-go/v2/internal/retry"
 	"github.com/tikv/client-go/v2/kv"
 	"github.com/tikv/client-go/v2/metrics"
 	"github.com/tikv/client-go/v2/tikvrpc"
diff --git a/internal/locate/region_request3_test.go b/internal/locate/region_request3_test.go
index 2cb73d05..c8efb70c 100644
--- a/internal/locate/region_request3_test.go
+++ b/internal/locate/region_request3_test.go
@@ -49,11 +49,11 @@ import (
 	"github.com/pingcap/log"
 	"github.com/pkg/errors"
 	"github.com/stretchr/testify/suite"
+	"github.com/tikv/client-go/v2/config/retry"
 	tikverr "github.com/tikv/client-go/v2/error"
 	"github.com/tikv/client-go/v2/internal/apicodec"
 	"github.com/tikv/client-go/v2/internal/client"
 	"github.com/tikv/client-go/v2/internal/mockstore/mocktikv"
-	"github.com/tikv/client-go/v2/internal/retry"
 	"github.com/tikv/client-go/v2/kv"
 	"github.com/tikv/client-go/v2/oracle"
 	"github.com/tikv/client-go/v2/tikvrpc"
diff --git a/internal/locate/region_request_state_test.go b/internal/locate/region_request_state_test.go
index 826bd5a4..f012452b 100644
--- a/internal/locate/region_request_state_test.go
+++ b/internal/locate/region_request_state_test.go
@@ -28,10 +28,10 @@ import (
 	"github.com/pingcap/kvproto/pkg/metapb"
 	"github.com/pkg/errors"
 	"github.com/stretchr/testify/require"
+	"github.com/tikv/client-go/v2/config/retry"
 	tikverr "github.com/tikv/client-go/v2/error"
 	"github.com/tikv/client-go/v2/internal/apicodec"
 	"github.com/tikv/client-go/v2/internal/mockstore/mocktikv"
-	"github.com/tikv/client-go/v2/internal/retry"
 	"github.com/tikv/client-go/v2/kv"
 	"github.com/tikv/client-go/v2/metrics"
 	"github.com/tikv/client-go/v2/tikvrpc"
diff --git a/internal/locate/region_request_test.go b/internal/locate/region_request_test.go
index be7ad625..74158d7c 100644
--- a/internal/locate/region_request_test.go
+++ b/internal/locate/region_request_test.go
@@ -55,11 +55,11 @@ import (
 	"github.com/pkg/errors"
 	"github.com/stretchr/testify/suite"
 	"github.com/tikv/client-go/v2/config"
+	"github.com/tikv/client-go/v2/config/retry"
 	"github.com/tikv/client-go/v2/internal/apicodec"
 	"github.com/tikv/client-go/v2/internal/client"
 	"github.com/tikv/client-go/v2/internal/client/mock_server"
 	"github.com/tikv/client-go/v2/internal/mockstore/mocktikv"
-	"github.com/tikv/client-go/v2/internal/retry"
 	"github.com/tikv/client-go/v2/tikvrpc"
 	"google.golang.org/grpc"
 )
diff --git a/rawkv/rawkv.go b/rawkv/rawkv.go
index ddae7289..00412987 100644
--- a/rawkv/rawkv.go
+++ b/rawkv/rawkv.go
@@ -42,11 +42,11 @@ import (
 	"github.com/pingcap/kvproto/pkg/kvrpcpb"
 	"github.com/pkg/errors"
 	"github.com/tikv/client-go/v2/config"
+	"github.com/tikv/client-go/v2/config/retry"
 	tikverr "github.com/tikv/client-go/v2/error"
 	"github.com/tikv/client-go/v2/internal/client"
 	"github.com/tikv/client-go/v2/internal/kvrpc"
 	"github.com/tikv/client-go/v2/internal/locate"
-	"github.com/tikv/client-go/v2/internal/retry"
 	"github.com/tikv/client-go/v2/metrics"
 	"github.com/tikv/client-go/v2/tikv"
 	"github.com/tikv/client-go/v2/tikvrpc"
diff --git a/rawkv/rawkv_test.go b/rawkv/rawkv_test.go
index f5eefaa2..638cd1b9 100644
--- a/rawkv/rawkv_test.go
+++ b/rawkv/rawkv_test.go
@@ -42,9 +42,9 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/suite"
+	"github.com/tikv/client-go/v2/config/retry"
 	"github.com/tikv/client-go/v2/internal/locate"
 	"github.com/tikv/client-go/v2/internal/mockstore/mocktikv"
-	"github.com/tikv/client-go/v2/internal/retry"
 	"github.com/tikv/client-go/v2/kv"
 )
 
diff --git a/tikv/backoff.go b/tikv/backoff.go
index a125db17..0eca6304 100644
--- a/tikv/backoff.go
+++ b/tikv/backoff.go
@@ -37,7 +37,7 @@ package tikv
 import (
 	"context"
 
-	"github.com/tikv/client-go/v2/internal/retry"
+	"github.com/tikv/client-go/v2/config/retry"
 	"github.com/tikv/client-go/v2/kv"
 )
 
diff --git a/tikv/gc.go b/tikv/gc.go
index 0ce3bbc5..ae4d3eb7 100644
--- a/tikv/gc.go
+++ b/tikv/gc.go
@@ -23,10 +23,10 @@ import (
 	"github.com/pingcap/kvproto/pkg/kvrpcpb"
 	"github.com/pingcap/kvproto/pkg/metapb"
 	"github.com/pkg/errors"
+	"github.com/tikv/client-go/v2/config/retry"
 	tikverr "github.com/tikv/client-go/v2/error"
 	"github.com/tikv/client-go/v2/internal/locate"
 	"github.com/tikv/client-go/v2/internal/logutil"
-	"github.com/tikv/client-go/v2/internal/retry"
 	"github.com/tikv/client-go/v2/kv"
 	"github.com/tikv/client-go/v2/metrics"
 	"github.com/tikv/client-go/v2/tikvrpc"
diff --git a/tikv/kv.go b/tikv/kv.go
index cd353230..fbf45a2d 100644
--- a/tikv/kv.go
+++ b/tikv/kv.go
@@ -49,12 +49,12 @@ import (
 	"github.com/pingcap/kvproto/pkg/kvrpcpb"
 	"github.com/pkg/errors"
 	"github.com/tikv/client-go/v2/config"
+	"github.com/tikv/client-go/v2/config/retry"
 	tikverr "github.com/tikv/client-go/v2/error"
 	"github.com/tikv/client-go/v2/internal/client"
 	"github.com/tikv/client-go/v2/internal/latch"
 	"github.com/tikv/client-go/v2/internal/locate"
 	"github.com/tikv/client-go/v2/internal/logutil"
-	"github.com/tikv/client-go/v2/internal/retry"
 	"github.com/tikv/client-go/v2/kv"
 	"github.com/tikv/client-go/v2/metrics"
 	"github.com/tikv/client-go/v2/oracle"
diff --git a/tikv/split_region.go b/tikv/split_region.go
index 2844b388..5f9a7ece 100644
--- a/tikv/split_region.go
+++ b/tikv/split_region.go
@@ -44,12 +44,12 @@ import (
 	"github.com/pingcap/kvproto/pkg/metapb"
 	"github.com/pingcap/kvproto/pkg/pdpb"
 	"github.com/pkg/errors"
+	"github.com/tikv/client-go/v2/config/retry"
 	tikverr "github.com/tikv/client-go/v2/error"
 	"github.com/tikv/client-go/v2/internal/client"
 	"github.com/tikv/client-go/v2/internal/kvrpc"
 	"github.com/tikv/client-go/v2/internal/locate"
 	"github.com/tikv/client-go/v2/internal/logutil"
-	"github.com/tikv/client-go/v2/internal/retry"
 	"github.com/tikv/client-go/v2/kv"
 	"github.com/tikv/client-go/v2/tikvrpc"
 	"github.com/tikv/client-go/v2/txnkv/rangetask"
diff --git a/tikv/test_probe.go b/tikv/test_probe.go
index 234d2585..05c334c7 100644
--- a/tikv/test_probe.go
+++ b/tikv/test_probe.go
@@ -39,7 +39,7 @@ import (
 	"context"
 
 	"github.com/pingcap/kvproto/pkg/metapb"
-	"github.com/tikv/client-go/v2/internal/retry"
+	"github.com/tikv/client-go/v2/config/retry"
 	"github.com/tikv/client-go/v2/tikvrpc"
 	"github.com/tikv/client-go/v2/txnkv/transaction"
 	"github.com/tikv/client-go/v2/txnkv/txnlock"
diff --git a/txnkv/client.go b/txnkv/client.go
index cfb40f57..4d4a5f2d 100644
--- a/txnkv/client.go
+++ b/txnkv/client.go
@@ -21,7 +21,7 @@ import (
 	"github.com/pingcap/kvproto/pkg/kvrpcpb"
 	"github.com/pkg/errors"
 	"github.com/tikv/client-go/v2/config"
-	"github.com/tikv/client-go/v2/internal/retry"
+	"github.com/tikv/client-go/v2/config/retry"
 	"github.com/tikv/client-go/v2/oracle"
 	"github.com/tikv/client-go/v2/tikv"
 	"github.com/tikv/client-go/v2/txnkv/transaction"
diff --git a/txnkv/rangetask/delete_range.go b/txnkv/rangetask/delete_range.go
index 8ceb07c9..a4fbd94a 100644
--- a/txnkv/rangetask/delete_range.go
+++ b/txnkv/rangetask/delete_range.go
@@ -41,10 +41,10 @@ import (
 
 	"github.com/pingcap/kvproto/pkg/kvrpcpb"
 	"github.com/pkg/errors"
+	"github.com/tikv/client-go/v2/config/retry"
 	tikverr "github.com/tikv/client-go/v2/error"
 	"github.com/tikv/client-go/v2/internal/client"
 	"github.com/tikv/client-go/v2/internal/locate"
-	"github.com/tikv/client-go/v2/internal/retry"
 	"github.com/tikv/client-go/v2/kv"
 	"github.com/tikv/client-go/v2/tikvrpc"
 )
diff --git a/txnkv/rangetask/range_task.go b/txnkv/rangetask/range_task.go
index 620bf43c..aa9400c1 100644
--- a/txnkv/rangetask/range_task.go
+++ b/txnkv/rangetask/range_task.go
@@ -42,8 +42,8 @@ import (
 	"time"
 
 	"github.com/pkg/errors"
+	"github.com/tikv/client-go/v2/config/retry"
 	"github.com/tikv/client-go/v2/internal/logutil"
-	"github.com/tikv/client-go/v2/internal/retry"
 	"github.com/tikv/client-go/v2/kv"
 	"github.com/tikv/client-go/v2/metrics"
 	"go.uber.org/zap"
diff --git a/txnkv/transaction/2pc.go b/txnkv/transaction/2pc.go
index c7d99333..f145e55e 100644
--- a/txnkv/transaction/2pc.go
+++ b/txnkv/transaction/2pc.go
@@ -52,12 +52,12 @@ import (
 	"github.com/pkg/errors"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/tikv/client-go/v2/config"
+	"github.com/tikv/client-go/v2/config/retry"
 	tikverr "github.com/tikv/client-go/v2/error"
 	"github.com/tikv/client-go/v2/internal/client"
 	"github.com/tikv/client-go/v2/internal/latch"
 	"github.com/tikv/client-go/v2/internal/locate"
 	"github.com/tikv/client-go/v2/internal/logutil"
-	"github.com/tikv/client-go/v2/internal/retry"
 	"github.com/tikv/client-go/v2/internal/unionstore"
 	"github.com/tikv/client-go/v2/kv"
 	"github.com/tikv/client-go/v2/metrics"
diff --git a/txnkv/transaction/cleanup.go b/txnkv/transaction/cleanup.go
index b0803199..eaf0668d 100644
--- a/txnkv/transaction/cleanup.go
+++ b/txnkv/transaction/cleanup.go
@@ -38,9 +38,9 @@ import (
 	"github.com/pingcap/kvproto/pkg/kvrpcpb"
 	"github.com/pkg/errors"
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/tikv/client-go/v2/config/retry"
 	"github.com/tikv/client-go/v2/internal/client"
 	"github.com/tikv/client-go/v2/internal/logutil"
-	"github.com/tikv/client-go/v2/internal/retry"
 	"github.com/tikv/client-go/v2/metrics"
 	"github.com/tikv/client-go/v2/tikvrpc"
 	"go.uber.org/zap"
diff --git a/txnkv/transaction/commit.go b/txnkv/transaction/commit.go
index 9e3eac4f..bf5302e6 100644
--- a/txnkv/transaction/commit.go
+++ b/txnkv/transaction/commit.go
@@ -42,11 +42,11 @@ import (
 	"github.com/pingcap/kvproto/pkg/kvrpcpb"
 	"github.com/pkg/errors"
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/tikv/client-go/v2/config/retry"
 	tikverr "github.com/tikv/client-go/v2/error"
 	"github.com/tikv/client-go/v2/internal/client"
 	"github.com/tikv/client-go/v2/internal/locate"
 	"github.com/tikv/client-go/v2/internal/logutil"
-	"github.com/tikv/client-go/v2/internal/retry"
 	"github.com/tikv/client-go/v2/metrics"
 	"github.com/tikv/client-go/v2/tikvrpc"
 	"go.uber.org/zap"
diff --git a/txnkv/transaction/pessimistic.go b/txnkv/transaction/pessimistic.go
index 28835bae..2f18bd11 100644
--- a/txnkv/transaction/pessimistic.go
+++ b/txnkv/transaction/pessimistic.go
@@ -45,11 +45,11 @@ import (
 	"github.com/pingcap/kvproto/pkg/kvrpcpb"
 	"github.com/pkg/errors"
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/tikv/client-go/v2/config/retry"
 	tikverr "github.com/tikv/client-go/v2/error"
 	"github.com/tikv/client-go/v2/internal/client"
 	"github.com/tikv/client-go/v2/internal/locate"
 	"github.com/tikv/client-go/v2/internal/logutil"
-	"github.com/tikv/client-go/v2/internal/retry"
 	"github.com/tikv/client-go/v2/kv"
 	"github.com/tikv/client-go/v2/metrics"
 	"github.com/tikv/client-go/v2/tikvrpc"
diff --git a/txnkv/transaction/prewrite.go b/txnkv/transaction/prewrite.go
index e83fee3f..fac2f4f5 100644
--- a/txnkv/transaction/prewrite.go
+++ b/txnkv/transaction/prewrite.go
@@ -46,11 +46,11 @@ import (
 	"github.com/pkg/errors"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/tikv/client-go/v2/config"
+	"github.com/tikv/client-go/v2/config/retry"
 	tikverr "github.com/tikv/client-go/v2/error"
 	"github.com/tikv/client-go/v2/internal/client"
 	"github.com/tikv/client-go/v2/internal/locate"
 	"github.com/tikv/client-go/v2/internal/logutil"
-	"github.com/tikv/client-go/v2/internal/retry"
 	"github.com/tikv/client-go/v2/metrics"
 	"github.com/tikv/client-go/v2/oracle"
 	"github.com/tikv/client-go/v2/tikvrpc"
diff --git a/txnkv/transaction/test_probe.go b/txnkv/transaction/test_probe.go
index f35017f8..1d88754f 100644
--- a/txnkv/transaction/test_probe.go
+++ b/txnkv/transaction/test_probe.go
@@ -20,8 +20,8 @@ import (
 	"sync/atomic"
 	"time"
 
+	"github.com/tikv/client-go/v2/config/retry"
 	"github.com/tikv/client-go/v2/internal/locate"
-	"github.com/tikv/client-go/v2/internal/retry"
 	"github.com/tikv/client-go/v2/internal/unionstore"
 	"github.com/tikv/client-go/v2/kv"
 	"github.com/tikv/client-go/v2/tikvrpc"
diff --git a/txnkv/transaction/txn.go b/txnkv/transaction/txn.go
index 2d5407a3..63f5eafd 100644
--- a/txnkv/transaction/txn.go
+++ b/txnkv/transaction/txn.go
@@ -54,9 +54,9 @@ import (
 	"github.com/pingcap/kvproto/pkg/kvrpcpb"
 	"github.com/pkg/errors"
 	"github.com/tikv/client-go/v2/config"
+	"github.com/tikv/client-go/v2/config/retry"
 	tikverr "github.com/tikv/client-go/v2/error"
 	"github.com/tikv/client-go/v2/internal/logutil"
-	"github.com/tikv/client-go/v2/internal/retry"
 	"github.com/tikv/client-go/v2/internal/unionstore"
 	tikv "github.com/tikv/client-go/v2/kv"
 	"github.com/tikv/client-go/v2/metrics"
diff --git a/txnkv/txnlock/lock_resolver.go b/txnkv/txnlock/lock_resolver.go
index b93b86eb..bd668a1f 100644
--- a/txnkv/txnlock/lock_resolver.go
+++ b/txnkv/txnlock/lock_resolver.go
@@ -28,11 +28,11 @@ import (
 	"github.com/pingcap/kvproto/pkg/kvrpcpb"
 	"github.com/pkg/errors"
 	"github.com/tikv/client-go/v2/config"
+	"github.com/tikv/client-go/v2/config/retry"
 	tikverr "github.com/tikv/client-go/v2/error"
 	"github.com/tikv/client-go/v2/internal/client"
 	"github.com/tikv/client-go/v2/internal/locate"
 	"github.com/tikv/client-go/v2/internal/logutil"
-	"github.com/tikv/client-go/v2/internal/retry"
 	"github.com/tikv/client-go/v2/metrics"
 	"github.com/tikv/client-go/v2/oracle"
 	"github.com/tikv/client-go/v2/tikvrpc"
diff --git a/txnkv/txnlock/test_probe.go b/txnkv/txnlock/test_probe.go
index f65a6097..67468bd3 100644
--- a/txnkv/txnlock/test_probe.go
+++ b/txnkv/txnlock/test_probe.go
@@ -17,8 +17,8 @@ package txnlock
 import (
 	"github.com/pingcap/kvproto/pkg/kvrpcpb"
 	"github.com/pkg/errors"
+	"github.com/tikv/client-go/v2/config/retry"
 	"github.com/tikv/client-go/v2/internal/locate"
-	"github.com/tikv/client-go/v2/internal/retry"
 )
 
 // LockProbe exposes some lock utilities for testing purpose.
diff --git a/txnkv/txnsnapshot/client_helper.go b/txnkv/txnsnapshot/client_helper.go
index 259f2192..bd927806 100644
--- a/txnkv/txnsnapshot/client_helper.go
+++ b/txnkv/txnsnapshot/client_helper.go
@@ -37,9 +37,9 @@ package txnsnapshot
 import (
 	"time"
 
+	"github.com/tikv/client-go/v2/config/retry"
 	"github.com/tikv/client-go/v2/internal/client"
 	"github.com/tikv/client-go/v2/internal/locate"
-	"github.com/tikv/client-go/v2/internal/retry"
 	"github.com/tikv/client-go/v2/tikvrpc"
 	"github.com/tikv/client-go/v2/txnkv/txnlock"
 	"github.com/tikv/client-go/v2/util"
diff --git a/txnkv/txnsnapshot/scan.go b/txnkv/txnsnapshot/scan.go
index 59c8fca8..c3fa8b02 100644
--- a/txnkv/txnsnapshot/scan.go
+++ b/txnkv/txnsnapshot/scan.go
@@ -40,11 +40,11 @@ import (
 
 	"github.com/pingcap/kvproto/pkg/kvrpcpb"
 	"github.com/pkg/errors"
+	"github.com/tikv/client-go/v2/config/retry"
 	tikverr "github.com/tikv/client-go/v2/error"
 	"github.com/tikv/client-go/v2/internal/client"
 	"github.com/tikv/client-go/v2/internal/locate"
 	"github.com/tikv/client-go/v2/internal/logutil"
-	"github.com/tikv/client-go/v2/internal/retry"
 	"github.com/tikv/client-go/v2/kv"
 	"github.com/tikv/client-go/v2/tikvrpc"
 	"github.com/tikv/client-go/v2/tikvrpc/interceptor"
diff --git a/txnkv/txnsnapshot/snapshot.go b/txnkv/txnsnapshot/snapshot.go
index 2fc6879c..a44aff52 100644
--- a/txnkv/txnsnapshot/snapshot.go
+++ b/txnkv/txnsnapshot/snapshot.go
@@ -47,11 +47,11 @@ import (
 	"github.com/pingcap/kvproto/pkg/kvrpcpb"
 	"github.com/pingcap/kvproto/pkg/metapb"
 	"github.com/pkg/errors"
+	"github.com/tikv/client-go/v2/config/retry"
 	tikverr "github.com/tikv/client-go/v2/error"
 	"github.com/tikv/client-go/v2/internal/client"
 	"github.com/tikv/client-go/v2/internal/locate"
 	"github.com/tikv/client-go/v2/internal/logutil"
-	"github.com/tikv/client-go/v2/internal/retry"
 	"github.com/tikv/client-go/v2/internal/unionstore"
 	"github.com/tikv/client-go/v2/kv"
 	"github.com/tikv/client-go/v2/metrics"
diff --git a/txnkv/txnsnapshot/test_probe.go b/txnkv/txnsnapshot/test_probe.go
index e1d4d931..f55e40d4 100644
--- a/txnkv/txnsnapshot/test_probe.go
+++ b/txnkv/txnsnapshot/test_probe.go
@@ -16,8 +16,8 @@ package txnsnapshot
 
 import (
 	"github.com/pingcap/kvproto/pkg/kvrpcpb"
+	"github.com/tikv/client-go/v2/config/retry"
 	"github.com/tikv/client-go/v2/internal/locate"
-	"github.com/tikv/client-go/v2/internal/retry"
 	"github.com/tikv/client-go/v2/tikvrpc"
 )