txn: distinguish write conflict reasons (#37735)

close #37734

DEPS.bzl

@@ -2796,8 +2796,8 @@ def go_deps():
         name = "com_github_pingcap_kvproto",
         build_file_proto_mode = "disable_global",
         importpath = "github.com/pingcap/kvproto",
-        sum = "h1:5q7Ns0R7q6Uj+fpa3lDTijrcqgId4lNdGa2AG7izB5c=",
-        version = "v0.0.0-20220906053631-2e37953b2b43",
+        sum = "h1:HfAWnlVF7P1nNJvXP4ew1Lcnng/BnAVQ40AsUHKR5EA=",
+        version = "v0.0.0-20220908075542-7c004f4daf21",
     )
     go_repository(
         name = "com_github_pingcap_log",
@@ -3400,8 +3400,8 @@ def go_deps():
         name = "com_github_tikv_client_go_v2",
         build_file_proto_mode = "disable_global",
         importpath = "github.com/tikv/client-go/v2",
-        sum = "h1:wjRWmUl4QmJF7V0aUskjT8EjjpfWxi5o9SQR5S1nNWA=",
-        version = "v2.0.1-0.20220906094532-f867f498456f",
+        sum = "h1:p8XInTnkUlLabBT7bDS3aZCeemO6tJ/7b5mHN8WbSIE=",
+        version = "v2.0.1-0.20220913051514-ffaaf7131a8d",
     )
     go_repository(
         name = "com_github_tikv_pd_client",

errno/errname.go

@@ -1097,7 +1097,7 @@ var MySQLErrName = map[uint16]*mysql.ErrMessage{
 	ErrResolveLockTimeout:        mysql.Message("Resolve lock timeout", nil),
 	ErrRegionUnavailable:         mysql.Message("Region is unavailable", nil),
 	ErrGCTooEarly:                mysql.Message("GC life time is shorter than transaction duration, transaction starts at %v, GC safe point is %v", nil),
-	ErrWriteConflict:             mysql.Message("Write conflict, txnStartTS=%d, conflictStartTS=%d, conflictCommitTS=%d, key=%s", []int{3}),
+	ErrWriteConflict:             mysql.Message("Write conflict, txnStartTS=%d, conflictStartTS=%d, conflictCommitTS=%d, key=%s, reason=%s", []int{3}),
 	ErrTiKVStoreLimit:            mysql.Message("Store token is up to the limit, store id = %d", nil),
 	ErrPrometheusAddrIsNotSet:    mysql.Message("Prometheus address is not set in PD and etcd", nil),
 	ErrTiKVStaleCommand:          mysql.Message("TiKV server reports stale command", nil),

errors.toml

@@ -1688,7 +1688,7 @@ not implemented
 
 ["kv:9007"]
 error = '''
-Write conflict, txnStartTS=%d, conflictStartTS=%d, conflictCommitTS=%d, key=%s [try again later]
+Write conflict, txnStartTS=%d, conflictStartTS=%d, conflictCommitTS=%d, key=%s, reason=%s [try again later]
 '''
 
 ["meta:1007"]

go.mod

@@ -63,7 +63,7 @@ require (
 	github.com/pingcap/errors v0.11.5-0.20211224045212-9687c2b0f87c
 	github.com/pingcap/failpoint v0.0.0-20220423142525-ae43b7f4e5c3
 	github.com/pingcap/fn v0.0.0-20200306044125-d5540d389059
-	github.com/pingcap/kvproto v0.0.0-20220906053631-2e37953b2b43
+	github.com/pingcap/kvproto v0.0.0-20220908075542-7c004f4daf21
 	github.com/pingcap/log v1.1.0
 	github.com/pingcap/sysutil v0.0.0-20220114020952-ea68d2dbf5b4
 	github.com/pingcap/tidb/parser v0.0.0-20211011031125-9b13dc409c5e
@@ -81,7 +81,7 @@ require (
 	github.com/stretchr/testify v1.8.0
 	github.com/tdakkota/asciicheck v0.1.1
 	github.com/tiancaiamao/appdash v0.0.0-20181126055449-889f96f722a2
-	github.com/tikv/client-go/v2 v2.0.1-0.20220906094532-f867f498456f
+	github.com/tikv/client-go/v2 v2.0.1-0.20220913051514-ffaaf7131a8d
 	github.com/tikv/pd/client v0.0.0-20220725055910-7187a7ab72db
 	github.com/timakin/bodyclose v0.0.0-20210704033933-f49887972144
 	github.com/twmb/murmur3 v1.1.3

go.sum

@@ -758,8 +758,8 @@ github.com/pingcap/goleveldb v0.0.0-20191226122134-f82aafb29989 h1:surzm05a8C9dN
 github.com/pingcap/goleveldb v0.0.0-20191226122134-f82aafb29989/go.mod h1:O17XtbryoCJhkKGbT62+L2OlrniwqiGLSqrmdHCMzZw=
 github.com/pingcap/kvproto v0.0.0-20191211054548-3c6b38ea5107/go.mod h1:WWLmULLO7l8IOcQG+t+ItJ3fEcrL5FxF0Wu+HrMy26w=
 github.com/pingcap/kvproto v0.0.0-20220510035547-0e2f26c0a46a/go.mod h1:OYtxs0786qojVTmkVeufx93xe+jUgm56GUYRIKnmaGI=
-github.com/pingcap/kvproto v0.0.0-20220906053631-2e37953b2b43 h1:5q7Ns0R7q6Uj+fpa3lDTijrcqgId4lNdGa2AG7izB5c=
-github.com/pingcap/kvproto v0.0.0-20220906053631-2e37953b2b43/go.mod h1:OYtxs0786qojVTmkVeufx93xe+jUgm56GUYRIKnmaGI=
+github.com/pingcap/kvproto v0.0.0-20220908075542-7c004f4daf21 h1:HfAWnlVF7P1nNJvXP4ew1Lcnng/BnAVQ40AsUHKR5EA=
+github.com/pingcap/kvproto v0.0.0-20220908075542-7c004f4daf21/go.mod h1:OYtxs0786qojVTmkVeufx93xe+jUgm56GUYRIKnmaGI=
 github.com/pingcap/log v0.0.0-20191012051959-b742a5d432e9/go.mod h1:4rbK1p9ILyIfb6hU7OG2CiWSqMXnp3JMbiaVJ6mvoY8=
 github.com/pingcap/log v0.0.0-20200511115504-543df19646ad/go.mod h1:4rbK1p9ILyIfb6hU7OG2CiWSqMXnp3JMbiaVJ6mvoY8=
 github.com/pingcap/log v0.0.0-20210625125904-98ed8e2eb1c7/go.mod h1:8AanEdAHATuRurdGxZXBz0At+9avep+ub7U1AGYLIMM=
@@ -912,8 +912,8 @@ github.com/tenntenn/text/transform v0.0.0-20200319021203-7eef512accb3 h1:f+jULpR
 github.com/tenntenn/text/transform v0.0.0-20200319021203-7eef512accb3/go.mod h1:ON8b8w4BN/kE1EOhwT0o+d62W65a6aPw1nouo9LMgyY=
 github.com/tiancaiamao/appdash v0.0.0-20181126055449-889f96f722a2 h1:mbAskLJ0oJfDRtkanvQPiooDH8HvJ2FBh+iKT/OmiQQ=
 github.com/tiancaiamao/appdash v0.0.0-20181126055449-889f96f722a2/go.mod h1:2PfKggNGDuadAa0LElHrByyrz4JPZ9fFx6Gs7nx7ZZU=
-github.com/tikv/client-go/v2 v2.0.1-0.20220906094532-f867f498456f h1:wjRWmUl4QmJF7V0aUskjT8EjjpfWxi5o9SQR5S1nNWA=
-github.com/tikv/client-go/v2 v2.0.1-0.20220906094532-f867f498456f/go.mod h1:tkKDJ88lryb16v7FfCh8pvvfwwCkh4aGeSOqHviPaaE=
+github.com/tikv/client-go/v2 v2.0.1-0.20220913051514-ffaaf7131a8d h1:p8XInTnkUlLabBT7bDS3aZCeemO6tJ/7b5mHN8WbSIE=
+github.com/tikv/client-go/v2 v2.0.1-0.20220913051514-ffaaf7131a8d/go.mod h1:6pedLz7wiINLHXwCT1+yMZmzuG42+ubtBkkfcwoukIo=
 github.com/tikv/pd/client v0.0.0-20220725055910-7187a7ab72db h1:r1eMh9Rny3hfWuBuxOnbsCRrR4FhthiNxLQ5rAUtaww=
 github.com/tikv/pd/client v0.0.0-20220725055910-7187a7ab72db/go.mod h1:ew8kS0yIcEaSetuuywkTLIUBR+sz3J5XvAYRae11qwc=
 github.com/timakin/bodyclose v0.0.0-20210704033933-f49887972144 h1:kl4KhGNsJIbDHS9/4U9yQo1UcPQM0kOMJHn29EoH/Ro=

store/driver/txn/driver_test.go

@@ -36,12 +36,13 @@ func TestWriteConflictPrettyFormat(t *testing.T) {
 		ConflictCommitTs: 399402937719455773,
 		Key:              []byte{116, 128, 0, 0, 0, 0, 0, 1, 155, 95, 105, 128, 0, 0, 0, 0, 0, 0, 1, 1, 82, 87, 48, 49, 0, 0, 0, 0, 251, 1, 55, 54, 56, 50, 50, 49, 49, 48, 255, 57, 0, 0, 0, 0, 0, 0, 0, 248, 1, 0, 0, 0, 0, 0, 0, 0, 0, 247},
 		Primary:          []byte{116, 128, 0, 0, 0, 0, 0, 1, 155, 95, 105, 128, 0, 0, 0, 0, 0, 0, 1, 1, 82, 87, 48, 49, 0, 0, 0, 0, 251, 1, 55, 54, 56, 50, 50, 49, 49, 48, 255, 57, 0, 0, 0, 0, 0, 0, 0, 248, 1, 0, 0, 0, 0, 0, 0, 0, 0, 247},
+		Reason:           kvrpcpb.WriteConflict_Unknown,
 	}
 
 	expectedStr := "[kv:9007]Write conflict, " +
 		"txnStartTS=399402937522847774, conflictStartTS=399402937719455772, conflictCommitTS=399402937719455773, " +
 		"key={tableID=411, indexID=1, indexValues={RW01, 768221109, , }} " +
-		"primary={tableID=411, indexID=1, indexValues={RW01, 768221109, , }} " +
+		"primary={tableID=411, indexID=1, indexValues={RW01, 768221109, , }}, reason=Unknown " +
 		kv.TxnRetryableMark
 	require.EqualError(t, newWriteConflictError(conflict), expectedStr)
 
@@ -51,11 +52,12 @@ func TestWriteConflictPrettyFormat(t *testing.T) {
 		ConflictCommitTs: 399402937719455773,
 		Key:              []byte{0x6d, 0x44, 0x42, 0x3a, 0x35, 0x36, 0x0, 0x0, 0x0, 0xfc, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x68, 0x54, 0x49, 0x44, 0x3a, 0x31, 0x30, 0x38, 0x0, 0xfe},
 		Primary:          []byte{0x6d, 0x44, 0x42, 0x3a, 0x35, 0x36, 0x0, 0x0, 0x0, 0xfc, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x68, 0x54, 0x49, 0x44, 0x3a, 0x31, 0x30, 0x38, 0x0, 0xfe},
+		Reason:           kvrpcpb.WriteConflict_Optimistic,
 	}
 	expectedStr = "[kv:9007]Write conflict, " +
 		"txnStartTS=399402937522847774, conflictStartTS=399402937719455772, conflictCommitTS=399402937719455773, " +
 		"key={metaKey=true, key=DB:56, field=TID:108} " +
-		"primary={metaKey=true, key=DB:56, field=TID:108} " +
+		"primary={metaKey=true, key=DB:56, field=TID:108}, reason=Optimistic " +
 		kv.TxnRetryableMark
 	require.EqualError(t, newWriteConflictError(conflict), expectedStr)
 }

store/driver/txn/error.go

@@ -162,7 +162,7 @@ func newWriteConflictError(conflict *kvrpcpb.WriteConflict) error {
 	prettyWriteKey(&buf, conflict.Key)
 	buf.WriteString(" primary=")
 	prettyWriteKey(&buf, conflict.Primary)
-	return kv.ErrWriteConflict.FastGenByArgs(conflict.StartTs, conflict.ConflictTs, conflict.ConflictCommitTs, buf.String())
+	return kv.ErrWriteConflict.FastGenByArgs(conflict.StartTs, conflict.ConflictTs, conflict.ConflictCommitTs, buf.String(), conflict.Reason.String())
 }
 
 func prettyWriteKey(buf *bytes.Buffer, key []byte) {

store/mockstore/unistore/tikv/dbreader/db_reader.go

@@ -332,6 +332,7 @@ func (r *DBReader) CheckWriteItemForRcCheckTSRead(readTS uint64, item *badger.It
 			StartTS:          readTS,
 			ConflictTS:       userMeta.StartTS(),
 			ConflictCommitTS: userMeta.CommitTS(),
+			Reason:           kvrpcpb.WriteConflict_RcCheckTs,
 		}
 	}
 	return nil

store/mockstore/unistore/tikv/kverrors/errors.go

@@ -106,6 +106,7 @@ type ErrConflict struct {
 	ConflictTS       uint64
 	ConflictCommitTS uint64
 	Key              []byte
+	Reason           kvrpcpb.WriteConflict_Reason
 }
 
 func (*ErrConflict) Error() string {

store/mockstore/unistore/tikv/mvcc.go

@@ -580,6 +580,7 @@ func (store *MVCCStore) buildPessimisticLock(m *kvrpcpb.Mutation, item *badger.I
 					ConflictTS:       userMeta.StartTS(),
 					ConflictCommitTS: userMeta.CommitTS(),
 					Key:              item.KeyCopy(nil),
+					Reason:           kvrpcpb.WriteConflict_PessimisticRetry,
 				}
 			}
 		}
@@ -668,6 +669,7 @@ func (store *MVCCStore) prewriteOptimistic(reqCtx *requestCtx, mutations []*kvrp
 					ConflictTS:       userMeta.StartTS(),
 					ConflictCommitTS: userMeta.CommitTS(),
 					Key:              item.KeyCopy(nil),
+					Reason:           kvrpcpb.WriteConflict_Optimistic,
 				}
 			}
 		}
@@ -729,6 +731,7 @@ func (store *MVCCStore) prewritePessimistic(reqCtx *requestCtx, mutations []*kvr
 						ConflictTS:       userMeta.StartTS(),
 						ConflictCommitTS: userMeta.CommitTS(),
 						Key:              item.KeyCopy(nil),
+						Reason:           kvrpcpb.WriteConflict_LazyUniquenessCheck,
 					}
 				}
 			}
@@ -1200,6 +1203,7 @@ func checkLockForRcCheckTS(lock mvcc.Lock, key []byte, startTS uint64, resolved
 		StartTS:    startTS,
 		ConflictTS: lock.StartTS,
 		Key:        safeCopy(key),
+		Reason:     kvrpcpb.WriteConflict_RcCheckTs,
 	}
 }
 

store/mockstore/unistore/tikv/server.go

@@ -1036,6 +1036,7 @@ func convertToKeyError(err error) *kvrpcpb.KeyError {
 				ConflictTs:       x.ConflictTS,
 				ConflictCommitTs: x.ConflictCommitTS,
 				Key:              x.Key,
+				Reason:           x.Reason,
 			},
 		}
 	case *kverrors.ErrDeadlock:

tests/realtikvtest/pessimistictest/pessimistic_test.go

@@ -3155,8 +3155,7 @@ func TestLazyUniquenessCheckForSimpleInserts(t *testing.T) {
 	tk2.MustExec("insert into t values (1, 1)")
 	tk2.MustExec("commit")
 	_, err := tk.Exec("commit")
-	require.NotNil(t, err)
-	require.Contains(t, err.Error(), "[kv:9007]Write conflict")
+	require.ErrorContains(t, err, "[kv:9007]Write conflict")
 	tk.MustQuery("select * from t").Check(testkit.Rows("1 1"))
 	tk.MustExec("admin check table t")
 
@@ -3168,8 +3167,7 @@ func TestLazyUniquenessCheckForSimpleInserts(t *testing.T) {
 	tk2.MustExec("insert into t2 values (2, 0)")
 	tk2.MustExec("commit")
 	_, err = tk.Exec("commit")
-	require.NotNil(t, err)
-	require.Contains(t, err.Error(), "[kv:9007]Write conflict")
+	require.ErrorContains(t, err, "[kv:9007]Write conflict")
 	tk.MustQuery("select * from t2").Check(testkit.Rows("2 0"))
 	tk.MustExec("admin check table t2")
 }
@@ -3205,22 +3203,8 @@ func TestLazyUniquenessCheck(t *testing.T) {
 	tk.MustExec("commit")
 	tk.MustExec("admin check table t")
 
-	// case: constraint check failure
-	tk.MustExec("create table t2 (id int primary key, uk int, unique key i1(uk))")
-	tk.MustExec("insert into t2 values (1, 1)")
-	tk.MustExec("begin pessimistic")
-	tk.MustExec("insert into t2 values (2, 1), (3, 3)")
-	// NOTE: this read breaks constraint, but we are not able to return an error here.
-	// We can only guarantee the txn should not commit
-	tk.MustQuery("select * from t2 use index(primary) for update").Check(testkit.Rows("1 1", "2 1", "3 3"))
-	err := tk.ExecToErr("commit")
-	require.Error(t, err)
-	require.Contains(t, err.Error(), "Duplicate entry '1' for key 'i1'")
-	tk.MustQuery("select * from t2 use index(primary)").Check(testkit.Rows("1 1"))
-	tk.MustExec("admin check table t2")
-
 	// case: a modification of a lazy-checked key will compensate the lock
-	tk.MustExec("truncate table t2")
+	tk.MustExec("create table t2 (id int primary key, uk int, unique key i1(uk))")
 	tk.MustExec("begin pessimistic")
 	tk.MustExec("insert into t2 values (1, 1)") // skip lock
 	tk.MustExec("update t2 set uk = uk + 1")    // compensate the lock
@@ -3232,19 +3216,19 @@ func TestLazyUniquenessCheck(t *testing.T) {
 	}()
 	time.Sleep(500 * time.Millisecond)
 	tk.MustExec("commit")
-	err = <-ch
+	err := <-ch
 	require.NoError(t, err)
 	tk.MustQuery("select * from t2").Check(testkit.Rows("1 12"))
 	tk.MustExec("admin check table t")
 
-	// case: conflict check failure
+	// case: conflict check failure, it doesn't commit in the optimistic way though there is no lock acquired in the txn
 	tk.MustExec("create table t3 (id int primary key, sk int, key i1(sk))")
 	tk.MustExec("begin pessimistic")
 	tk.MustExec("insert into t3 values (1, 1)")
 	tk2.MustExec("insert into t3 values (1, 2)")
 	err = tk.ExecToErr("commit")
-	require.Error(t, err)
-	require.Contains(t, err.Error(), "[kv:9007]Write conflict")
+	require.ErrorContains(t, err, "[kv:9007]Write conflict")
+	require.ErrorContains(t, err, "reason=LazyUniquenessCheck")
 
 	// case: DML returns error => abort txn
 	tk.MustExec("create table t4 (id int primary key, v int, key i1(v))")
@@ -3253,8 +3237,7 @@ func TestLazyUniquenessCheck(t *testing.T) {
 	tk.MustExec("insert into t4 values (1, 2), (2, 2)")
 	tk.MustQuery("select * from t4 order by id").Check(testkit.Rows("1 2", "2 2"))
 	err = tk.ExecToErr("delete from t4 where id = 1")
-	require.Error(t, err)
-	require.Contains(t, err.Error(), "transaction aborted because lazy uniqueness check is enabled and an error occurred: [kv:1062]Duplicate entry '1' for key 'PRIMARY'")
+	require.ErrorContains(t, err, "transaction aborted because lazy uniqueness check is enabled and an error occurred: [kv:1062]Duplicate entry '1' for key 'PRIMARY'")
 	tk.MustExec("commit")
 	tk.MustExec("admin check table t4")
 	tk.MustQuery("select * from t4 order by id").Check(testkit.Rows("1 1"))
@@ -3267,16 +3250,15 @@ func TestLazyUniquenessCheck(t *testing.T) {
 	tk2.MustExec("delete from t5 where uk = 2")
 	tk.MustExec("select * from t5 for update")
 	err = tk.ExecToErr("commit")
-	require.Contains(t, err.Error(), "[kv:9007]Write conflict")
+	require.ErrorContains(t, err, "[kv:9007]Write conflict")
 
 	// case: delete your own insert that should've returned error
 	tk.MustExec("truncate table t5")
 	tk.MustExec("insert into t5 values (1, 1)")
 	tk.MustExec("begin pessimistic")
 	tk.MustExec("insert into t5 values (2, 1)")
 	err = tk.ExecToErr("delete from t5")
-	require.Error(t, err)
-	require.Contains(t, err.Error(), "transaction aborted because lazy uniqueness check is enabled and an error occurred: [kv:1062]Duplicate entry '1' for key 'i1'")
+	require.ErrorContains(t, err, "transaction aborted because lazy uniqueness check is enabled and an error occurred: [kv:1062]Duplicate entry '1' for key 'i1'")
 	require.False(t, tk.Session().GetSessionVars().InTxn())
 
 	// case: update unique key, but conflict exists before the txn
@@ -3285,8 +3267,7 @@ func TestLazyUniquenessCheck(t *testing.T) {
 	tk.MustExec("begin pessimistic")
 	tk.MustExec("update t5 set uk = 3 where id = 1")
 	err = tk.ExecToErr("commit")
-	require.Error(t, err)
-	require.Contains(t, err.Error(), "Duplicate entry '3' for key 'i1'")
+	require.ErrorContains(t, err, "Duplicate entry '3' for key 'i1'")
 	tk.MustExec("admin check table t5")
 
 	// case: update unique key, but conflict with concurrent write
@@ -3296,8 +3277,7 @@ func TestLazyUniquenessCheck(t *testing.T) {
 	tk.MustExec("update t5 set uk = 3 where id = 1")
 	tk2.MustExec("insert into t5 values (2, 3)")
 	err = tk.ExecToErr("commit")
-	require.Error(t, err)
-	require.Contains(t, err.Error(), "[kv:9007]Write conflict")
+	require.ErrorContains(t, err, "[kv:9007]Write conflict")
 	tk.MustExec("admin check table t5")
 
 	// case: insert on duplicate update unique key, but conflict exists before the txn
@@ -3306,8 +3286,7 @@ func TestLazyUniquenessCheck(t *testing.T) {
 	tk.MustExec("begin pessimistic")
 	tk.MustExec("insert into t5 values (3, 1) on duplicate key update uk = 3")
 	err = tk.ExecToErr("commit")
-	require.Error(t, err)
-	require.Contains(t, err.Error(), "Duplicate entry '3' for key 'i1'")
+	require.ErrorContains(t, err, "Duplicate entry '3' for key 'i1'")
 	tk.MustExec("admin check table t5")
 
 	// case: insert on duplicate update unique key, but conflict with concurrent write
@@ -3317,12 +3296,12 @@ func TestLazyUniquenessCheck(t *testing.T) {
 	tk.MustExec("insert into t5 values (3, 1) on duplicate key update uk = 3")
 	tk2.MustExec("insert into t5 values (2, 3)")
 	err = tk.ExecToErr("commit")
-	require.Error(t, err)
-	require.Contains(t, err.Error(), "[kv:9007]Write conflict")
+	require.ErrorContains(t, err, "[kv:9007]Write conflict")
 	tk.MustExec("admin check table t5")
 }
 
 func TestLazyUniquenessCheckForInsertIgnore(t *testing.T) {
+	// lazy uniqueness check doesn't affect INSERT IGNORE
 	store := realtikvtest.CreateMockStoreAndSetup(t)
 	tk := testkit.NewTestKit(t, store)
 	tk.MustExec("use test")
@@ -3364,8 +3343,8 @@ func TestLazyUniquenessCheckWithStatementRetry(t *testing.T) {
 	tk.MustExec("insert into t5 values (3, 3)") // skip handle=3, uk=3
 	tk2.MustExec("insert into t5 values (2, 3)")
 	err := tk.ExecToErr("update t5 set id = 10 where uk = 3") // write conflict -> unset PresumeKNE -> retry
-	require.Error(t, err)
-	require.Contains(t, err.Error(), "Duplicate entry '3' for key 'i1'")
+	require.ErrorContains(t, err, "transaction aborted because lazy uniqueness")
+	require.ErrorContains(t, err, "Duplicate entry '3' for key 'i1'")
 	require.False(t, tk.Session().GetSessionVars().InTxn())
 	tk.MustExec("admin check table t5")
 
@@ -3376,8 +3355,42 @@ func TestLazyUniquenessCheckWithStatementRetry(t *testing.T) {
 	tk.MustExec("insert into t5 values (3, 3)") // skip handle=3, uk=3
 	tk2.MustExec("insert into t5 values (2, 3)")
 	err = tk.ExecToErr("update t5 set id = id + 10") // write conflict -> unset PresumeKNE -> retry
-	require.Error(t, err)
-	require.Contains(t, err.Error(), "Duplicate entry '3' for key 'i1'")
+	require.ErrorContains(t, err, "Duplicate entry '3' for key 'i1'")
 	require.False(t, tk.Session().GetSessionVars().InTxn())
 	tk.MustExec("admin check table t5")
 }
+
+func TestLazyUniquenessCheckWithInconsistentReadResult(t *testing.T) {
+	// If any read breaks constraint, we guarantee the txn cannot commit
+	store := realtikvtest.CreateMockStoreAndSetup(t)
+	tk := testkit.NewTestKit(t, store)
+	tk2 := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+	tk2.MustExec("use test")
+	tk.MustExec("set @@tidb_constraint_check_in_place_pessimistic=0")
+	// TiKV will perform a constraint check before reporting assertion failure.
+	// And constraint violation precedes assertion failure.
+	if !*realtikvtest.WithRealTiKV {
+		tk.MustExec("set @@tidb_txn_assertion_level=off")
+	}
+
+	// case: conflict data has been there before current txn
+	tk.MustExec("create table t2 (id int primary key, uk int, unique key i1(uk))")
+	tk.MustExec("insert into t2 values (1, 1)")
+	tk.MustExec("begin pessimistic")
+	tk.MustExec("insert into t2 values (2, 1), (3, 3)")
+	tk.MustQuery("select * from t2 use index(primary) for update").Check(testkit.Rows("1 1", "2 1", "3 3"))
+	err := tk.ExecToErr("commit")
+	require.ErrorContains(t, err, "Duplicate entry '1' for key 'i1'")
+	tk.MustQuery("select * from t2 use index(primary)").Check(testkit.Rows("1 1"))
+	tk.MustExec("admin check table t2")
+
+	// case: conflict data is written concurrently
+	tk.MustExec("truncate table t2")
+	tk.MustExec("begin pessimistic")
+	tk.MustExec("insert into t2 values (1, 1)")
+	tk2.MustExec("insert into t2 values (2, 1)")
+	tk.MustQuery("select * from t2 use index(primary) for update").Check(testkit.Rows("1 1", "2 1"))
+	err = tk.ExecToErr("commit")
+	require.ErrorContains(t, err, "reason=LazyUniquenessCheck")
+}