br: fix the split issue in txn restore (#45441)

Makefile

@@ -327,6 +327,7 @@ build_for_br_integration_test:
 	$(GOBUILD) $(RACE_FLAG) -o bin/gc br/tests/br_z_gc_safepoint/*.go && \
 	$(GOBUILD) $(RACE_FLAG) -o bin/oauth br/tests/br_gcs/*.go && \
 	$(GOBUILD) $(RACE_FLAG) -o bin/rawkv br/tests/br_rawkv/*.go && \
+	$(GOBUILD) $(RACE_FLAG) -o bin/txnkv br/tests/br_txn/*.go && \
 	$(GOBUILD) $(RACE_FLAG) -o bin/parquet_gen br/tests/lightning_checkpoint_parquet/*.go \
 	) || (make failpoint-disable && exit 1)
 	@make failpoint-disable

br/pkg/task/restore_txn.go

@@ -87,7 +87,7 @@ func RunRestoreTxn(c context.Context, g glue.Glue, cmdName string, cfg *Config)
 		!cfg.LogProgress)
 
 	// RawKV restore does not need to rewrite keys.
-	err = restore.SplitRanges(ctx, client, ranges, nil, updateCh, true)
+	err = restore.SplitRanges(ctx, client, ranges, nil, updateCh, false)
 	if err != nil {
 		return errors.Trace(err)
 	}

br/tests/br_txn/BUILD.bazel

@@ -0,0 +1,21 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
+
+go_library(
+    name = "br_txn_lib",
+    srcs = ["client.go"],
+    importpath = "github.com/pingcap/tidb/br/tests/br_txn",
+    visibility = ["//visibility:private"],
+    deps = [
+        "@com_github_pingcap_errors//:errors",
+        "@com_github_pingcap_log//:log",
+        "@com_github_tikv_client_go_v2//config",
+        "@com_github_tikv_client_go_v2//txnkv",
+        "@org_uber_go_zap//:zap",
+    ],
+)
+
+go_binary(
+    name = "br_txn",
+    embed = [":br_txn_lib"],
+    visibility = ["//visibility:public"],
+)

br/tests/br_txn/client.go

@@ -0,0 +1,268 @@
+package main
+
+import (
+	"bytes"
+	"context"
+	"encoding/hex"
+	"flag"
+	"fmt"
+	"hash/crc64"
+	"math/rand"
+	"time"
+
+	"github.com/pingcap/errors"
+	"github.com/pingcap/log"
+	"github.com/tikv/client-go/v2/config"
+	"github.com/tikv/client-go/v2/txnkv"
+	"go.uber.org/zap"
+)
+
+var (
+	ca          = flag.String("ca", "", "CA certificate path for TLS connection")
+	cert        = flag.String("cert", "", "certificate path for TLS connection")
+	key         = flag.String("key", "", "private key path for TLS connection")
+	pdAddr      = flag.String("pd", "127.0.0.1:2379", "Address of PD")
+	runMode     = flag.String("mode", "", "Mode. One of 'rand-gen', 'checksum', 'scan', 'delete'")
+	startKeyStr = flag.String("start-key", "", "Start key in hex")
+	endKeyStr   = flag.String("end-key", "", "End key in hex")
+	keyMaxLen   = flag.Int("key-max-len", 32, "Max length of keys for rand-gen mode")
+	concurrency = flag.Int("concurrency", 32, "Concurrency to run rand-gen")
+	duration    = flag.Int("duration", 10, "duration(second) of rand-gen")
+)
+
+func createClient(addr string) (*txnkv.Client, error) {
+	if *ca != "" {
+		conf := config.GetGlobalConfig()
+		conf.Security.ClusterSSLCA = *ca
+		conf.Security.ClusterSSLCert = *cert
+		conf.Security.ClusterSSLKey = *key
+		config.StoreGlobalConfig(conf)
+	}
+
+	cli, err := txnkv.NewClient([]string{addr})
+	return cli, errors.Trace(err)
+}
+
+func main() {
+	flag.Parse()
+
+	startKey := []byte(*startKeyStr)
+	endKey := []byte(*endKeyStr)
+	if len(endKey) == 0 {
+		log.Panic("Empty endKey is not supported yet")
+	}
+
+	if *runMode == "test-rand-key" {
+		testRandKey(startKey, endKey, *keyMaxLen)
+		return
+	}
+
+	client, err := createClient(*pdAddr)
+	if err != nil {
+		log.Panic("Failed to create client", zap.String("pd", *pdAddr), zap.Error(err))
+	}
+
+	switch *runMode {
+	case "rand-gen":
+		err = randGenWithDuration(client, startKey, endKey, *keyMaxLen, *concurrency, *duration)
+	case "checksum":
+		err = checksum(client, startKey, endKey)
+	case "delete":
+		err = deleteRange(client, startKey, endKey)
+	}
+
+	if err != nil {
+		log.Panic("Error", zap.Error(err))
+	}
+}
+
+func randGenWithDuration(client *txnkv.Client, startKey, endKey []byte,
+	maxLen int, concurrency int, duration int) error {
+	var err error
+	ok := make(chan struct{})
+	go func() {
+		err = randGen(client, startKey, endKey, maxLen, concurrency)
+		ok <- struct{}{}
+	}()
+	select {
+	case <-time.After(time.Second * time.Duration(duration)):
+	case <-ok:
+	}
+	return errors.Trace(err)
+}
+
+func randGen(client *txnkv.Client, startKey, endKey []byte, maxLen int, concurrency int) error {
+	log.Info("Start rand-gen", zap.Int("maxlen", maxLen),
+		zap.String("startkey", hex.EncodeToString(startKey)), zap.String("endkey", hex.EncodeToString(endKey)))
+	log.Info("Rand-gen will keep running. Please Ctrl+C to stop manually.")
+
+	// Cannot generate shorter key than commonPrefix
+	commonPrefixLen := 0
+	for ; commonPrefixLen < len(startKey) && commonPrefixLen < len(endKey) &&
+		startKey[commonPrefixLen] == endKey[commonPrefixLen]; commonPrefixLen++ {
+		continue
+	}
+
+	if maxLen < commonPrefixLen {
+		return errors.Errorf("maxLen (%v) < commonPrefixLen (%v)", maxLen, commonPrefixLen)
+	}
+
+	const batchSize = 32
+
+	errCh := make(chan error, concurrency)
+	for i := maxLen; i <= maxLen+concurrency; i++ {
+		go func(i int) {
+			for {
+				txn, err := client.Begin()
+				if err != nil {
+					errCh <- errors.Trace(err)
+				}
+				for j := 0; j < batchSize; j++ {
+					key := randKey(startKey, endKey, i)
+					// append index to avoid write conflict
+					key = appendIndex(key, i)
+					value := randValue()
+					err = txn.Set(key, value)
+					if err != nil {
+						errCh <- errors.Trace(err)
+					}
+				}
+				err = txn.Commit(context.TODO())
+				if err != nil {
+					errCh <- errors.Trace(err)
+				}
+			}
+		}(i)
+	}
+
+	err := <-errCh
+	if err != nil {
+		return errors.Trace(err)
+	}
+
+	return nil
+}
+
+func testRandKey(startKey, endKey []byte, maxLen int) {
+	for {
+		k := randKey(startKey, endKey, maxLen)
+		if bytes.Compare(k, startKey) < 0 || bytes.Compare(k, endKey) >= 0 {
+			panic(hex.EncodeToString(k))
+		}
+	}
+}
+
+//nolint:gosec
+func randKey(startKey, endKey []byte, maxLen int) []byte {
+Retry:
+	for { // Regenerate on fail
+		result := make([]byte, 0, maxLen)
+
+		upperUnbounded := false
+		lowerUnbounded := false
+
+		for i := 0; i < maxLen; i++ {
+			upperBound := 256
+			if !upperUnbounded {
+				if i >= len(endKey) {
+					// The generated key is the same as endKey which is invalid. Regenerate it.
+					continue Retry
+				}
+				upperBound = int(endKey[i]) + 1
+			}
+
+			lowerBound := 0
+			if !lowerUnbounded {
+				if i >= len(startKey) {
+					lowerUnbounded = true
+				} else {
+					lowerBound = int(startKey[i])
+				}
+			}
+
+			if lowerUnbounded {
+				if rand.Intn(257) == 0 {
+					return result
+				}
+			}
+
+			value := rand.Intn(upperBound - lowerBound)
+			value += lowerBound
+
+			if value < upperBound-1 {
+				upperUnbounded = true
+			}
+			if value > lowerBound {
+				lowerUnbounded = true
+			}
+
+			result = append(result, uint8(value))
+		}
+
+		return result
+	}
+}
+
+//nolint:gosec
+func appendIndex(key []byte, i int) []byte {
+	return append(key, uint8(i))
+}
+
+//nolint:gosec
+func randValue() []byte {
+	result := make([]byte, 0, 512)
+	for i := 0; i < 512; i++ {
+		value := rand.Intn(257)
+		if value == 256 {
+			if i > 0 {
+				return result
+			}
+			value--
+		}
+		result = append(result, uint8(value))
+	}
+	return result
+}
+
+func checksum(client *txnkv.Client, startKey, endKey []byte) error {
+	log.Info("Start checkcum on range",
+		zap.String("startkey", hex.EncodeToString(startKey)), zap.String("endkey", hex.EncodeToString(endKey)))
+
+	txn, err := client.Begin()
+	if err != nil {
+		return errors.Trace(err)
+	}
+	iter, err := txn.Iter(startKey, endKey)
+	if err != nil {
+		return errors.Trace(err)
+	}
+
+	digest := crc64.New(crc64.MakeTable(crc64.ECMA))
+
+	var res uint64
+
+	for iter.Valid() {
+		err := iter.Next()
+		if err != nil {
+			return errors.Trace(err)
+		}
+		if len(iter.Key()) == 0 {
+			break
+		}
+		_, _ = digest.Write(iter.Key())
+		_, _ = digest.Write(iter.Value())
+		res ^= digest.Sum64()
+	}
+	_ = txn.Commit(context.TODO())
+
+	log.Info("Checksum result", zap.Uint64("checksum", res))
+	fmt.Printf("Checksum result: %016x\n", res)
+	return nil
+}
+
+func deleteRange(client *txnkv.Client, startKey, endKey []byte) error {
+	log.Info("Start delete data in range",
+		zap.String("startkey", hex.EncodeToString(startKey)), zap.String("endkey", hex.EncodeToString(endKey)))
+	_, err := client.DeleteRange(context.TODO(), startKey, endKey, *concurrency)
+	return err
+}