infoschema, executor: Add the deadlock table

executor/builder.go

@@ -1534,7 +1534,9 @@ func (b *executorBuilder) buildMemTable(v *plannercore.PhysicalMemTable) Executo
 			strings.ToLower(infoschema.TableClientErrorsSummaryByUser),
 			strings.ToLower(infoschema.TableClientErrorsSummaryByHost),
 			strings.ToLower(infoschema.TableTiDBTrx),
-			strings.ToLower(infoschema.ClusterTableTiDBTrx):
+			strings.ToLower(infoschema.ClusterTableTiDBTrx),
+			strings.ToLower(infoschema.TableDeadlocks),
+			strings.ToLower(infoschema.ClusterTableDeadlocks):
 			return &MemTableReaderExec{
 				baseExecutor: newBaseExecutor(b.ctx, v.Schema(), v.ID()),
 				table:        v.Table,

executor/executor.go

@@ -49,6 +49,7 @@ import (
 	"github.com/pingcap/tidb/sessionctx/stmtctx"
 	"github.com/pingcap/tidb/sessionctx/variable"
 	"github.com/pingcap/tidb/store/tikv"
+	tikverr "github.com/pingcap/tidb/store/tikv/error"
 	tikvstore "github.com/pingcap/tidb/store/tikv/kv"
 	tikvutil "github.com/pingcap/tidb/store/tikv/util"
 	"github.com/pingcap/tidb/table"
@@ -58,6 +59,7 @@ import (
 	"github.com/pingcap/tidb/util"
 	"github.com/pingcap/tidb/util/admin"
 	"github.com/pingcap/tidb/util/chunk"
+	"github.com/pingcap/tidb/util/deadlockhistory"
 	"github.com/pingcap/tidb/util/disk"
 	"github.com/pingcap/tidb/util/execdetails"
 	"github.com/pingcap/tidb/util/logutil"
@@ -983,6 +985,13 @@ func newLockCtx(seVars *variable.SessionVars, lockWaitTime int64) *tikvstore.Loc
 		LockKeysCount:         &seVars.StmtCtx.LockKeysCount,
 		LockExpired:           &seVars.TxnCtx.LockExpire,
 		ResourceGroupTag:      resourcegrouptag.EncodeResourceGroupTag(sqlDigest),
+		OnDeadlock: func(deadlock *tikverr.ErrDeadlock) {
+			// TODO: Support collecting retryable deadlocks according to the config.
+			if !deadlock.IsRetryable {
+				rec := deadlockhistory.ErrDeadlockToDeadlockRecord(deadlock)
+				deadlockhistory.GlobalDeadlockHistory.Push(rec)
+			}
+		},
 	}
 }
 

executor/executor_test.go

@@ -70,6 +70,7 @@ import (
 	"github.com/pingcap/tidb/types"
 	"github.com/pingcap/tidb/util"
 	"github.com/pingcap/tidb/util/admin"
+	"github.com/pingcap/tidb/util/deadlockhistory"
 	"github.com/pingcap/tidb/util/gcutil"
 	"github.com/pingcap/tidb/util/logutil"
 	"github.com/pingcap/tidb/util/memory"
@@ -8151,7 +8152,71 @@ func (s *testSerialSuite) TestIssue24210(c *C) {
 	c.Assert(err.Error(), Equals, "mock SelectionExec.baseExecutor.Open returned error")
 	err = failpoint.Disable("github.com/pingcap/tidb/executor/mockSelectionExecBaseExecutorOpenReturnedError")
 	c.Assert(err, IsNil)
+}
+
+func (s *testSerialSuite) TestDeadlockTable(c *C) {
+	deadlockhistory.GlobalDeadlockHistory.Clear()
 
+	occurTime := time.Date(2021, 5, 10, 1, 2, 3, 456789000, time.UTC)
+	rec := &deadlockhistory.DeadlockRecord{
+		OccurTime:   occurTime,
+		IsRetryable: false,
+		WaitChain: []deadlockhistory.WaitChainItem{
+			{
+				TryLockTxn:     101,
+				SQLDigest:      "aabbccdd",
+				Key:            []byte("k1"),
+				AllSQLs:        nil,
+				TxnHoldingLock: 102,
+			},
+			{
+				TryLockTxn:     102,
+				SQLDigest:      "ddccbbaa",
+				Key:            []byte("k2"),
+				AllSQLs:        []string{"sql1"},
+				TxnHoldingLock: 101,
+			},
+		},
+	}
+	deadlockhistory.GlobalDeadlockHistory.Push(rec)
+
+	occurTime2 := time.Date(2022, 6, 11, 2, 3, 4, 987654000, time.UTC)
+	rec2 := &deadlockhistory.DeadlockRecord{
+		OccurTime:   occurTime2,
+		IsRetryable: true,
+		WaitChain: []deadlockhistory.WaitChainItem{
+			{
+				TryLockTxn:     201,
+				AllSQLs:        []string{},
+				TxnHoldingLock: 202,
+			},
+			{
+				TryLockTxn:     202,
+				AllSQLs:        []string{"sql1", "sql2, sql3"},
+				TxnHoldingLock: 203,
+			},
+			{
+				TryLockTxn:     203,
+				TxnHoldingLock: 201,
+			},
+		},
+	}
+	deadlockhistory.GlobalDeadlockHistory.Push(rec2)
+
+	// `Push` sets the record's ID, and ID in a single DeadlockHistory is monotonically increasing. We must get it here
+	// to know what it is.
+	id1 := strconv.FormatUint(rec.ID, 10)
+	id2 := strconv.FormatUint(rec2.ID, 10)
+
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustQuery("select * from information_schema.deadlocks").Check(
+		testutil.RowsWithSep("/",
+			id1+"/2021-05-10 01:02:03.456789/0/101/aabbccdd/6B31/<nil>/102",
+			id1+"/2021-05-10 01:02:03.456789/0/102/ddccbbaa/6B32/[sql1]/101",
+			id2+"/2022-06-11 02:03:04.987654/1/201/<nil>/<nil>/[]/202",
+			id2+"/2022-06-11 02:03:04.987654/1/202/<nil>/<nil>/[sql1, sql2, sql3]/203",
+			id2+"/2022-06-11 02:03:04.987654/1/203/<nil>/<nil>/<nil>/201",
+		))
 }
 
 func (s testSerialSuite) TestExprBlackListForEnum(c *C) {

executor/infoschema_reader.go

@@ -52,6 +52,7 @@ import (
 	"github.com/pingcap/tidb/util"
 	"github.com/pingcap/tidb/util/chunk"
 	"github.com/pingcap/tidb/util/collate"
+	"github.com/pingcap/tidb/util/deadlockhistory"
 	"github.com/pingcap/tidb/util/pdapi"
 	"github.com/pingcap/tidb/util/sem"
 	"github.com/pingcap/tidb/util/set"
@@ -153,6 +154,10 @@ func (e *memtableRetriever) retrieve(ctx context.Context, sctx sessionctx.Contex
 			e.setDataForTiDBTrx(sctx)
 		case infoschema.ClusterTableTiDBTrx:
 			err = e.setDataForClusterTiDBTrx(sctx)
+		case infoschema.TableDeadlocks:
+			err = e.setDataForDeadlock(sctx)
+		case infoschema.ClusterTableDeadlocks:
+			err = e.setDataForClusterDeadlock(sctx)
 		}
 		if err != nil {
 			return nil, err
@@ -2048,6 +2053,33 @@ func (e *memtableRetriever) setDataForClusterTiDBTrx(ctx sessionctx.Context) err
 	return nil
 }
 
+func (e *memtableRetriever) setDataForDeadlock(ctx sessionctx.Context) error {
+	hasPriv := false
+	if pm := privilege.GetPrivilegeManager(ctx); pm != nil {
+		hasPriv = pm.RequestVerification(ctx.GetSessionVars().ActiveRoles, "", "", "", mysql.ProcessPriv)
+	}
+
+	if !hasPriv {
+		return plannercore.ErrSpecificAccessDenied.GenWithStackByArgs("PROCESS")
+	}
+
+	e.rows = deadlockhistory.GlobalDeadlockHistory.GetAllDatum()
+	return nil
+}
+
+func (e *memtableRetriever) setDataForClusterDeadlock(ctx sessionctx.Context) error {
+	err := e.setDataForDeadlock(ctx)
+	if err != nil {
+		return err
+	}
+	rows, err := infoschema.AppendHostInfoToRows(ctx, e.rows)
+	if err != nil {
+		return err
+	}
+	e.rows = rows
+	return nil
+}
+
 type hugeMemTableRetriever struct {
 	dummyCloser
 	table       *model.TableInfo

infoschema/cluster.go

@@ -39,6 +39,8 @@ const (
 	ClusterTableStatementsSummaryHistory = "CLUSTER_STATEMENTS_SUMMARY_HISTORY"
 	// ClusterTableTiDBTrx is the string constant of cluster transaction running table.
 	ClusterTableTiDBTrx = "CLUSTER_TIDB_TRX"
+	// ClusterTableDeadlocks is the string constant of cluster dead lock table.
+	ClusterTableDeadlocks = "CLUSTER_DEADLOCKS"
 )
 
 // memTableToClusterTables means add memory table to cluster table.
@@ -48,6 +50,7 @@ var memTableToClusterTables = map[string]string{
 	TableStatementsSummary:        ClusterTableStatementsSummary,
 	TableStatementsSummaryHistory: ClusterTableStatementsSummaryHistory,
 	TableTiDBTrx:                  ClusterTableTiDBTrx,
+	TableDeadlocks:                ClusterTableDeadlocks,
 }
 
 func init() {

infoschema/tables.go

@@ -165,6 +165,8 @@ const (
 	TableClientErrorsSummaryByHost = "CLIENT_ERRORS_SUMMARY_BY_HOST"
 	// TableTiDBTrx is current running transaction status table.
 	TableTiDBTrx = "TIDB_TRX"
+	// TableDeadlocks is the string constatnt of deadlock table.
+	TableDeadlocks = "DEADLOCKS"
 )
 
 var tableIDMap = map[string]int64{
@@ -239,6 +241,8 @@ var tableIDMap = map[string]int64{
 	TableClientErrorsSummaryByHost:          autoid.InformationSchemaDBID + 69,
 	TableTiDBTrx:                            autoid.InformationSchemaDBID + 70,
 	ClusterTableTiDBTrx:                     autoid.InformationSchemaDBID + 71,
+	TableDeadlocks:                          autoid.InformationSchemaDBID + 72,
+	ClusterTableDeadlocks:                   autoid.InformationSchemaDBID + 73,
 }
 
 type columnInfo struct {
@@ -1353,6 +1357,17 @@ var tableTiDBTrxCols = []columnInfo{
 	{name: "DB", tp: mysql.TypeVarchar, size: 64, comment: "The schema this transaction works on"},
 }
 
+var tableDeadlocksCols = []columnInfo{
+	{name: "DEADLOCK_ID", tp: mysql.TypeLonglong, size: 21, flag: mysql.NotNullFlag, comment: "The ID to dinstinguish different deadlock events"},
+	{name: "OCCUR_TIME", tp: mysql.TypeTimestamp, decimal: 6, size: 26, comment: "The physical time when the deadlock occurs"},
+	{name: "RETRYABLE", tp: mysql.TypeTiny, size: 1, flag: mysql.NotNullFlag, comment: "Whether the deadlock is retryable. Retryable deadlocks are usually not reported to the client"},
+	{name: "TRY_LOCK_TRX_ID", tp: mysql.TypeLonglong, size: 21, flag: mysql.NotNullFlag, comment: "The transaction ID (start ts) of the transaction that's trying to acquire the lock"},
+	{name: "CURRENT_SQL_DIGEST", tp: mysql.TypeVarchar, size: 64, comment: "The digest of the SQL that's being blocked"},
+	{name: "KEY", tp: mysql.TypeBlob, size: types.UnspecifiedLength, comment: "The key on which a transaction is waiting for another"},
+	{name: "ALL_SQLS", tp: mysql.TypeBlob, size: types.UnspecifiedLength, comment: "A list of the digests of SQL statements that the transaction has executed"},
+	{name: "TRX_HOLDING_LOCK", tp: mysql.TypeLonglong, size: 21, flag: mysql.NotNullFlag, comment: "The transaction ID (start ts) of the transaction that's currently holding the lock"},
+}
+
 // GetShardingInfo returns a nil or description string for the sharding information of given TableInfo.
 // The returned description string may be:
 //  - "NOT_SHARDED": for tables that SHARD_ROW_ID_BITS is not specified.
@@ -1723,6 +1738,7 @@ var tableNameToColumns = map[string][]columnInfo{
 	TableClientErrorsSummaryByUser:          tableClientErrorsSummaryByUserCols,
 	TableClientErrorsSummaryByHost:          tableClientErrorsSummaryByHostCols,
 	TableTiDBTrx:                            tableTiDBTrxCols,
+	TableDeadlocks:                          tableDeadlocksCols,
 }
 
 func createInfoSchemaTable(_ autoid.Allocators, meta *model.TableInfo) (table.Table, error) {

infoschema/tables_test.go

@@ -1531,3 +1531,24 @@ func (s *testTableSuite) TestTrx(c *C) {
 		testkit.Rows("424768545227014155 2021-05-07 12:56:48 " + digest + " Normal <nil> 1 19 2 root test"),
 	)
 }
+
+func (s *testTableSuite) TestInfoschemaDeadlockPrivilege(c *C) {
+	tk := s.newTestKitWithRoot(c)
+	tk.MustExec("create user 'testuser'@'localhost'")
+	c.Assert(tk.Se.Auth(&auth.UserIdentity{
+		Username: "testuser",
+		Hostname: "localhost",
+	}, nil, nil), IsTrue)
+	err := tk.QueryToErr("select * from information_schema.deadlocks")
+	c.Assert(err, NotNil)
+	c.Assert(err.Error(), Equals, "[planner:1227]Access denied; you need (at least one of) the PROCESS privilege(s) for this operation")
+
+	tk = s.newTestKitWithRoot(c)
+	tk.MustExec("create user 'testuser2'@'localhost'")
+	tk.MustExec("grant process on *.* to 'testuser2'@'localhost'")
+	c.Assert(tk.Se.Auth(&auth.UserIdentity{
+		Username: "testuser2",
+		Hostname: "localhost",
+	}, nil, nil), IsTrue)
+	_ = tk.MustQuery("select * from information_schema.deadlocks")
+}

session/pessimistic_test.go

@@ -16,6 +16,7 @@ package session_test
 import (
 	"context"
 	"fmt"
+	"strconv"
 	"strings"
 	"sync"
 	"sync/atomic"
@@ -24,6 +25,7 @@ import (
 	. "github.com/pingcap/check"
 	"github.com/pingcap/errors"
 	"github.com/pingcap/failpoint"
+	"github.com/pingcap/parser"
 	"github.com/pingcap/parser/mysql"
 	"github.com/pingcap/parser/terror"
 	"github.com/pingcap/tidb/config"
@@ -37,6 +39,7 @@ import (
 	"github.com/pingcap/tidb/tablecodec"
 	"github.com/pingcap/tidb/types"
 	"github.com/pingcap/tidb/util/codec"
+	"github.com/pingcap/tidb/util/deadlockhistory"
 	"github.com/pingcap/tidb/util/testkit"
 )
 
@@ -171,27 +174,33 @@ func (s *testPessimisticSuite) TestTxnMode(c *C) {
 }
 
 func (s *testPessimisticSuite) TestDeadlock(c *C) {
-	tk := testkit.NewTestKitWithInit(c, s.store)
-	tk.MustExec("drop table if exists deadlock")
-	tk.MustExec("create table deadlock (k int primary key, v int)")
-	tk.MustExec("insert into deadlock values (1, 1), (2, 1)")
+	deadlockhistory.GlobalDeadlockHistory.Clear()
+
+	tk1 := testkit.NewTestKitWithInit(c, s.store)
+	tk1.MustExec("drop table if exists deadlock")
+	tk1.MustExec("create table deadlock (k int primary key, v int)")
+	tk1.MustExec("insert into deadlock values (1, 1), (2, 1)")
+	tk1.MustExec("begin pessimistic")
+	tk1.MustExec("update deadlock set v = v + 1 where k = 1")
+	ts1, err := strconv.ParseUint(tk1.MustQuery("select @@tidb_current_ts").Rows()[0][0].(string), 10, 64)
+	c.Assert(err, IsNil)
+
+	tk2 := testkit.NewTestKitWithInit(c, s.store)
+	tk2.MustExec("begin pessimistic")
+	ts2, err := strconv.ParseUint(tk2.MustQuery("select @@tidb_current_ts").Rows()[0][0].(string), 10, 64)
+	c.Assert(err, IsNil)
 
 	syncCh := make(chan error)
 	go func() {
-		tk1 := testkit.NewTestKitWithInit(c, s.store)
-		tk1.MustExec("begin pessimistic")
-		tk1.MustExec("update deadlock set v = v + 1 where k = 2")
+		tk2.MustExec("update deadlock set v = v + 1 where k = 2")
 		syncCh <- nil
-		_, err := tk1.Exec("update deadlock set v = v + 1 where k = 1")
+		_, err := tk2.Exec("update deadlock set v = v + 1 where k = 1")
 		syncCh <- err
 	}()
-	tk.MustExec("begin pessimistic")
-	tk.MustExec("update deadlock set v = v + 1 where k = 1")
 	<-syncCh
-	_, err1 := tk.Exec("update deadlock set v = v + 1 where k = 2")
+	_, err1 := tk1.Exec("update deadlock set v = v + 1 where k = 2")
 	err2 := <-syncCh
 	// Either err1 or err2 is deadlock error.
-	var err error
 	if err1 != nil {
 		c.Assert(err2, IsNil)
 		err = err1
@@ -201,6 +210,21 @@ func (s *testPessimisticSuite) TestDeadlock(c *C) {
 	e, ok := errors.Cause(err).(*terror.Error)
 	c.Assert(ok, IsTrue)
 	c.Assert(int(e.Code()), Equals, mysql.ErrLockDeadlock)
+
+	_, digest := parser.NormalizeDigest("update deadlock set v = v + 1 where k = 1")
+
+	expectedDeadlockInfo := []string{
+		fmt.Sprintf("%v %v %v", ts1, ts2, digest),
+		fmt.Sprintf("%v %v %v", ts2, ts1, digest),
+	}
+	// The last one is the transaction that encountered the deadlock error.
+	if err1 != nil {
+		// Swap the two to match the correct order.
+		expectedDeadlockInfo[0], expectedDeadlockInfo[1] = expectedDeadlockInfo[1], expectedDeadlockInfo[0]
+	}
+	res := tk1.MustQuery("select deadlock_id, try_lock_trx_id, trx_holding_lock, current_sql_digest from information_schema.deadlocks")
+	res.CheckAt([]int{1, 2, 3}, testkit.Rows(expectedDeadlockInfo...))
+	c.Assert(res.Rows()[0][0], Equals, res.Rows()[1][0])
 }
 
 func (s *testPessimisticSuite) TestSingleStatementRollback(c *C) {

store/tikv/kv/kv.go

@@ -4,6 +4,7 @@ import (
 	"sync"
 	"time"
 
+	tikverr "github.com/pingcap/tidb/store/tikv/error"
 	"github.com/pingcap/tidb/store/tikv/util"
 )
 
@@ -28,4 +29,5 @@ type LockCtx struct {
 	LockExpired           *uint32
 	Stats                 *util.LockKeysDetails
 	ResourceGroupTag      []byte
+	OnDeadlock            func(*tikverr.ErrDeadlock)
 }

store/tikv/txn.go

@@ -642,8 +642,13 @@ func (txn *KVTxn) LockKeys(ctx context.Context, lockCtx *tikv.LockCtx, keysInput
 			keyMayBeLocked := !(tikverr.IsErrWriteConflict(err) || tikverr.IsErrKeyExist(err))
 			// If there is only 1 key and lock fails, no need to do pessimistic rollback.
 			if len(keys) > 1 || keyMayBeLocked {
+				dl, ok := errors.Cause(err).(*tikverr.ErrDeadlock)
+				if ok && lockCtx.OnDeadlock != nil {
+					// Call OnDeadlock before pessimistic rollback.
+					lockCtx.OnDeadlock(dl)
+				}
 				wg := txn.asyncPessimisticRollback(ctx, keys)
-				if dl, ok := errors.Cause(err).(*tikverr.ErrDeadlock); ok {
+				if ok {
 					logutil.Logger(ctx).Debug("deadlock error received", zap.Uint64("startTS", txn.startTS), zap.Stringer("deadlockInfo", dl))
 					if hashInKeys(dl.DeadlockKeyHash, keys) {
 						dl.IsRetryable = true