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// Copyright 2015 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,
// See the License for the specific language governing permissions and
// limitations under the License.
package executor
import (
"context"
"fmt"
"math"
"runtime/trace"
"strconv"
"strings"
"sync/atomic"
"time"
"github.com/opentracing/opentracing-go"
"github.com/pingcap/errors"
"github.com/pingcap/log"
"github.com/pingcap/parser/ast"
"github.com/pingcap/parser/model"
"github.com/pingcap/parser/mysql"
"github.com/pingcap/parser/terror"
"github.com/pingcap/tidb/config"
"github.com/pingcap/tidb/domain"
"github.com/pingcap/tidb/expression"
"github.com/pingcap/tidb/infoschema"
"github.com/pingcap/tidb/kv"
"github.com/pingcap/tidb/metrics"
"github.com/pingcap/tidb/planner"
plannercore "github.com/pingcap/tidb/planner/core"
"github.com/pingcap/tidb/plugin"
"github.com/pingcap/tidb/sessionctx"
"github.com/pingcap/tidb/sessionctx/variable"
"github.com/pingcap/tidb/store/tikv"
"github.com/pingcap/tidb/types"
"github.com/pingcap/tidb/util/chunk"
"github.com/pingcap/tidb/util/execdetails"
"github.com/pingcap/tidb/util/logutil"
"github.com/pingcap/tidb/util/memory"
"github.com/pingcap/tidb/util/plancodec"
"github.com/pingcap/tidb/util/sqlexec"
"github.com/pingcap/tidb/util/stmtsummary"
"github.com/pingcap/tidb/util/stringutil"
"go.uber.org/zap"
"go.uber.org/zap/zapcore"
)
// processinfoSetter is the interface use to set current running process info.
type processinfoSetter interface {
SetProcessInfo(string, time.Time, byte, uint64)
}
// recordSet wraps an executor, implements sqlexec.RecordSet interface
type recordSet struct {
fields []*ast.ResultField
executor Executor
stmt *ExecStmt
lastErr error
txnStartTS uint64
}
func (a *recordSet) Fields() []*ast.ResultField {
if len(a.fields) == 0 {
a.fields = colNames2ResultFields(a.executor.Schema(), a.stmt.OutputNames, a.stmt.Ctx.GetSessionVars().CurrentDB)
}
return a.fields
}
func colNames2ResultFields(schema *expression.Schema, names []*types.FieldName, defaultDB string) []*ast.ResultField {
rfs := make([]*ast.ResultField, 0, schema.Len())
defaultDBCIStr := model.NewCIStr(defaultDB)
for i := 0; i < schema.Len(); i++ {
dbName := names[i].DBName
if dbName.L == "" && names[i].TblName.L != "" {
dbName = defaultDBCIStr
}
origColName := names[i].OrigColName
if origColName.L == "" {
origColName = names[i].ColName
}
rf := &ast.ResultField{
Column: &model.ColumnInfo{Name: origColName, FieldType: *schema.Columns[i].RetType},
ColumnAsName: names[i].ColName,
Table: &model.TableInfo{Name: names[i].OrigTblName},
TableAsName: names[i].TblName,
DBName: dbName,
}
// This is for compatibility.
// See issue https://github.com/pingcap/tidb/issues/10513 .
if len(rf.ColumnAsName.O) > mysql.MaxAliasIdentifierLen {
rf.ColumnAsName.O = rf.ColumnAsName.O[:mysql.MaxAliasIdentifierLen]
}
// Usually the length of O equals the length of L.
// Add this len judgement to avoid panic.
if len(rf.ColumnAsName.L) > mysql.MaxAliasIdentifierLen {
rf.ColumnAsName.L = rf.ColumnAsName.L[:mysql.MaxAliasIdentifierLen]
}
rfs = append(rfs, rf)
}
return rfs
}
// Next use uses recordSet's executor to get next available chunk for later usage.
// If chunk does not contain any rows, then we update last query found rows in session variable as current found rows.
// The reason we need update is that chunk with 0 rows indicating we already finished current query, we need prepare for
// next query.
// If stmt is not nil and chunk with some rows inside, we simply update last query found rows by the number of row in chunk.
func (a *recordSet) Next(ctx context.Context, req *chunk.Chunk) (err error) {
defer func() {
r := recover()
if r == nil {
return
}
err = errors.Errorf("%v", r)
logutil.Logger(ctx).Error("execute sql panic", zap.String("sql", a.stmt.GetTextToLog()), zap.Stack("stack"))
}()
err = Next(ctx, a.executor, req)
if err != nil {
a.lastErr = err
return err
}
numRows := req.NumRows()
if numRows == 0 {
if a.stmt != nil {
a.stmt.Ctx.GetSessionVars().LastFoundRows = a.stmt.Ctx.GetSessionVars().StmtCtx.FoundRows()
}
return nil
}
if a.stmt != nil {
a.stmt.Ctx.GetSessionVars().StmtCtx.AddFoundRows(uint64(numRows))
}
return nil
}
// NewChunk create a chunk base on top-level executor's newFirstChunk().
func (a *recordSet) NewChunk() *chunk.Chunk {
return newFirstChunk(a.executor)
}
func (a *recordSet) Close() error {
err := a.executor.Close()
a.stmt.CloseRecordSet(a.txnStartTS, a.lastErr)
return err
}
// OnFetchReturned implements commandLifeCycle#OnFetchReturned
func (a *recordSet) OnFetchReturned() {
a.stmt.LogSlowQuery(a.txnStartTS, a.lastErr == nil, true)
}
// ExecStmt implements the sqlexec.Statement interface, it builds a planner.Plan to an sqlexec.Statement.
type ExecStmt struct {
// GoCtx stores parent go context.Context for a stmt.
GoCtx context.Context
// InfoSchema stores a reference to the schema information.
InfoSchema infoschema.InfoSchema
// Plan stores a reference to the final physical plan.
Plan plannercore.Plan
// Text represents the origin query text.
Text string
StmtNode ast.StmtNode
Ctx sessionctx.Context
// LowerPriority represents whether to lower the execution priority of a query.
LowerPriority bool
isPreparedStmt bool
isSelectForUpdate bool
retryCount uint
retryStartTime time.Time
// OutputNames will be set if using cached plan
OutputNames []*types.FieldName
PsStmt *plannercore.CachedPrepareStmt
}
// PointGet short path for point exec directly from plan, keep only necessary steps
func (a *ExecStmt) PointGet(ctx context.Context, is infoschema.InfoSchema) (*recordSet, error) {
if span := opentracing.SpanFromContext(ctx); span != nil && span.Tracer() != nil {
span1 := span.Tracer().StartSpan("ExecStmt.PointGet", opentracing.ChildOf(span.Context()))
span1.LogKV("sql", a.OriginText())
defer span1.Finish()
ctx = opentracing.ContextWithSpan(ctx, span1)
}
startTs := uint64(math.MaxUint64)
err := a.Ctx.InitTxnWithStartTS(startTs)
if err != nil {
return nil, err
}
a.Ctx.GetSessionVars().StmtCtx.Priority = kv.PriorityHigh
// try to reuse point get executor
if a.PsStmt.Executor != nil {
exec, ok := a.PsStmt.Executor.(*PointGetExecutor)
if !ok {
logutil.Logger(ctx).Error("invalid executor type, not PointGetExecutor for point get path")
a.PsStmt.Executor = nil
} else {
// CachedPlan type is already checked in last step
pointGetPlan := a.PsStmt.PreparedAst.CachedPlan.(*plannercore.PointGetPlan)
exec.Init(pointGetPlan, startTs)
a.PsStmt.Executor = exec
}
}
if a.PsStmt.Executor == nil {
b := newExecutorBuilder(a.Ctx, is)
newExecutor := b.build(a.Plan)
if b.err != nil {
return nil, b.err
}
a.PsStmt.Executor = newExecutor
}
pointExecutor := a.PsStmt.Executor.(*PointGetExecutor)
if err = pointExecutor.Open(ctx); err != nil {
terror.Call(pointExecutor.Close)
return nil, err
}
return &recordSet{
executor: pointExecutor,
stmt: a,
txnStartTS: startTs,
}, nil
}
// OriginText returns original statement as a string.
func (a *ExecStmt) OriginText() string {
return a.Text
}
// IsPrepared returns true if stmt is a prepare statement.
func (a *ExecStmt) IsPrepared() bool {
return a.isPreparedStmt
}
// IsReadOnly returns true if a statement is read only.
// If current StmtNode is an ExecuteStmt, we can get its prepared stmt,
// then using ast.IsReadOnly function to determine a statement is read only or not.
func (a *ExecStmt) IsReadOnly(vars *variable.SessionVars) bool {
return planner.IsReadOnly(a.StmtNode, vars)
}
// RebuildPlan rebuilds current execute statement plan.
// It returns the current information schema version that 'a' is using.
func (a *ExecStmt) RebuildPlan(ctx context.Context) (int64, error) {
is := infoschema.GetInfoSchema(a.Ctx)
a.InfoSchema = is
if err := plannercore.Preprocess(a.Ctx, a.StmtNode, is, plannercore.InTxnRetry); err != nil {
return 0, err
}
p, names, err := planner.Optimize(ctx, a.Ctx, a.StmtNode, is)
if err != nil {
return 0, err
}
a.OutputNames = names
a.Plan = p
return is.SchemaMetaVersion(), nil
}
// Exec builds an Executor from a plan. If the Executor doesn't return result,
// like the INSERT, UPDATE statements, it executes in this function, if the Executor returns
// result, execution is done after this function returns, in the returned sqlexec.RecordSet Next method.
func (a *ExecStmt) Exec(ctx context.Context) (_ sqlexec.RecordSet, err error) {
defer func() {
r := recover()
if r == nil {
if a.retryCount > 0 {
metrics.StatementPessimisticRetryCount.Observe(float64(a.retryCount))
}
lockKeysCnt := a.Ctx.GetSessionVars().StmtCtx.LockKeysCount
if lockKeysCnt > 0 {
metrics.StatementLockKeysCount.Observe(float64(lockKeysCnt))
}
return
}
if str, ok := r.(string); !ok || !strings.HasPrefix(str, memory.PanicMemoryExceed) {
panic(r)
}
err = errors.Errorf("%v", r)
logutil.Logger(ctx).Error("execute sql panic", zap.String("sql", a.GetTextToLog()), zap.Stack("stack"))
}()
sctx := a.Ctx
ctx = sessionctx.SetCommitCtx(ctx, sctx)
if _, ok := a.Plan.(*plannercore.Analyze); ok && sctx.GetSessionVars().InRestrictedSQL {
oriStats, _ := sctx.GetSessionVars().GetSystemVar(variable.TiDBBuildStatsConcurrency)
oriScan := sctx.GetSessionVars().DistSQLScanConcurrency
oriIndex := sctx.GetSessionVars().IndexSerialScanConcurrency
oriIso, _ := sctx.GetSessionVars().GetSystemVar(variable.TxnIsolation)
terror.Log(sctx.GetSessionVars().SetSystemVar(variable.TiDBBuildStatsConcurrency, "1"))
sctx.GetSessionVars().DistSQLScanConcurrency = 1
sctx.GetSessionVars().IndexSerialScanConcurrency = 1
terror.Log(sctx.GetSessionVars().SetSystemVar(variable.TxnIsolation, ast.ReadCommitted))
defer func() {
terror.Log(sctx.GetSessionVars().SetSystemVar(variable.TiDBBuildStatsConcurrency, oriStats))
sctx.GetSessionVars().DistSQLScanConcurrency = oriScan
sctx.GetSessionVars().IndexSerialScanConcurrency = oriIndex
terror.Log(sctx.GetSessionVars().SetSystemVar(variable.TxnIsolation, oriIso))
}()
}
if sctx.GetSessionVars().StmtCtx.HasMemQuotaHint {
sctx.GetSessionVars().StmtCtx.MemTracker.SetBytesLimit(sctx.GetSessionVars().StmtCtx.MemQuotaQuery)
}
e, err := a.buildExecutor()
if err != nil {
return nil, err
}
if err = e.Open(ctx); err != nil {
terror.Call(e.Close)
return nil, err
}
cmd32 := atomic.LoadUint32(&sctx.GetSessionVars().CommandValue)
cmd := byte(cmd32)
var pi processinfoSetter
if raw, ok := sctx.(processinfoSetter); ok {
pi = raw
sql := a.OriginText()
if simple, ok := a.Plan.(*plannercore.Simple); ok && simple.Statement != nil {
if ss, ok := simple.Statement.(ast.SensitiveStmtNode); ok {
// Use SecureText to avoid leak password information.
sql = ss.SecureText()
}
}
maxExecutionTime := getMaxExecutionTime(sctx)
// Update processinfo, ShowProcess() will use it.
pi.SetProcessInfo(sql, time.Now(), cmd, maxExecutionTime)
if a.Ctx.GetSessionVars().StmtCtx.StmtType == "" {
a.Ctx.GetSessionVars().StmtCtx.StmtType = GetStmtLabel(a.StmtNode)
}
}
isPessimistic := sctx.GetSessionVars().TxnCtx.IsPessimistic
// Special handle for "select for update statement" in pessimistic transaction.
if isPessimistic && a.isSelectForUpdate {
return a.handlePessimisticSelectForUpdate(ctx, e)
}
if handled, result, err := a.handleNoDelay(ctx, e, isPessimistic); handled {
return result, err
}
var txnStartTS uint64
txn, err := sctx.Txn(false)
if err != nil {
return nil, err
}
if txn.Valid() {
txnStartTS = txn.StartTS()
}
return &recordSet{
executor: e,
stmt: a,
txnStartTS: txnStartTS,
}, nil
}
func (a *ExecStmt) handleNoDelay(ctx context.Context, e Executor, isPessimistic bool) (handled bool, rs sqlexec.RecordSet, err error) {
sc := a.Ctx.GetSessionVars().StmtCtx
defer func() {
// If the stmt have no rs like `insert`, The session tracker detachment will be directly
// done in the `defer` function. If the rs is not nil, the detachment will be done in
// `rs.Close` in `handleStmt`
if sc != nil && rs == nil {
if sc.DiskTracker != nil {
sc.DiskTracker.DetachFromGlobalTracker()
}
}
}()
toCheck := e
isExplainAnalyze := false
if explain, ok := e.(*ExplainExec); ok {
if analyze := explain.getAnalyzeExecToExecutedNoDelay(); analyze != nil {
toCheck = analyze
isExplainAnalyze = true
}
}
// If the executor doesn't return any result to the client, we execute it without delay.
if toCheck.Schema().Len() == 0 {
handled = !isExplainAnalyze
if isPessimistic {
return handled, nil, a.handlePessimisticDML(ctx, toCheck)
}
r, err := a.handleNoDelayExecutor(ctx, toCheck)
return handled, r, err
} else if proj, ok := toCheck.(*ProjectionExec); ok && proj.calculateNoDelay {
// Currently this is only for the "DO" statement. Take "DO 1, @a=2;" as an example:
// the Projection has two expressions and two columns in the schema, but we should
// not return the result of the two expressions.
r, err := a.handleNoDelayExecutor(ctx, e)
return true, r, err
}
return false, nil, nil
}
// getMaxExecutionTime get the max execution timeout value.
func getMaxExecutionTime(sctx sessionctx.Context) uint64 {
if sctx.GetSessionVars().StmtCtx.HasMaxExecutionTime {
return sctx.GetSessionVars().StmtCtx.MaxExecutionTime
}
return sctx.GetSessionVars().MaxExecutionTime
}
type chunkRowRecordSet struct {
rows []chunk.Row
idx int
fields []*ast.ResultField
e Executor
execStmt *ExecStmt
}
func (c *chunkRowRecordSet) Fields() []*ast.ResultField {
return c.fields
}
func (c *chunkRowRecordSet) Next(ctx context.Context, chk *chunk.Chunk) error {
chk.Reset()
for !chk.IsFull() && c.idx < len(c.rows) {
chk.AppendRow(c.rows[c.idx])
c.idx++
}
return nil
}
func (c *chunkRowRecordSet) NewChunk() *chunk.Chunk {
return newFirstChunk(c.e)
}
func (c *chunkRowRecordSet) Close() error {
c.execStmt.CloseRecordSet(c.execStmt.Ctx.GetSessionVars().TxnCtx.StartTS, nil)
return nil
}
func (a *ExecStmt) handlePessimisticSelectForUpdate(ctx context.Context, e Executor) (sqlexec.RecordSet, error) {
for {
rs, err := a.runPessimisticSelectForUpdate(ctx, e)
e, err = a.handlePessimisticLockError(ctx, err)
if err != nil {
return nil, err
}
if e == nil {
return rs, nil
}
}
}
func (a *ExecStmt) runPessimisticSelectForUpdate(ctx context.Context, e Executor) (sqlexec.RecordSet, error) {
defer func() {
terror.Log(e.Close())
}()
var rows []chunk.Row
var err error
req := newFirstChunk(e)
for {
err = Next(ctx, e, req)
if err != nil {
// Handle 'write conflict' error.
break
}
if req.NumRows() == 0 {
fields := colNames2ResultFields(e.Schema(), a.OutputNames, a.Ctx.GetSessionVars().CurrentDB)
return &chunkRowRecordSet{rows: rows, fields: fields, e: e, execStmt: a}, nil
}
iter := chunk.NewIterator4Chunk(req)
for r := iter.Begin(); r != iter.End(); r = iter.Next() {
rows = append(rows, r)
}
req = chunk.Renew(req, a.Ctx.GetSessionVars().MaxChunkSize)
}
return nil, err
}
func (a *ExecStmt) handleNoDelayExecutor(ctx context.Context, e Executor) (sqlexec.RecordSet, error) {
sctx := a.Ctx
if span := opentracing.SpanFromContext(ctx); span != nil && span.Tracer() != nil {
span1 := span.Tracer().StartSpan("executor.handleNoDelayExecutor", opentracing.ChildOf(span.Context()))
defer span1.Finish()
ctx = opentracing.ContextWithSpan(ctx, span1)
}
// Check if "tidb_snapshot" is set for the write executors.
// In history read mode, we can not do write operations.
switch e.(type) {
case *DeleteExec, *InsertExec, *UpdateExec, *ReplaceExec, *LoadDataExec, *DDLExec:
snapshotTS := sctx.GetSessionVars().SnapshotTS
if snapshotTS != 0 {
return nil, errors.New("can not execute write statement when 'tidb_snapshot' is set")
}
lowResolutionTSO := sctx.GetSessionVars().LowResolutionTSO
if lowResolutionTSO {
return nil, errors.New("can not execute write statement when 'tidb_low_resolution_tso' is set")
}
}
var err error
defer func() {
terror.Log(e.Close())
a.logAudit()
}()
err = Next(ctx, e, newFirstChunk(e))
if err != nil {
return nil, err
}
return nil, err
}
func (a *ExecStmt) handlePessimisticDML(ctx context.Context, e Executor) error {
sctx := a.Ctx
// Do not active the transaction here.
// When autocommit = 0 and transaction in pessimistic mode,
// statements like set xxx = xxx; should not active the transaction.
txn, err := sctx.Txn(false)
if err != nil {
return err
}
txnCtx := sctx.GetSessionVars().TxnCtx
for {
startPointGetLocking := time.Now()
_, err = a.handleNoDelayExecutor(ctx, e)
if !txn.Valid() {
return err
}
if err != nil {
// It is possible the DML has point get plan that locks the key.
e, err = a.handlePessimisticLockError(ctx, err)
if err != nil {
if ErrDeadlock.Equal(err) {
metrics.StatementDeadlockDetectDuration.Observe(time.Since(startPointGetLocking).Seconds())
}
return err
}
continue
}
keys, err1 := txn.(pessimisticTxn).KeysNeedToLock()
if err1 != nil {
return err1
}
keys = txnCtx.CollectUnchangedRowKeys(keys)
if len(keys) == 0 {
return nil
}
seVars := sctx.GetSessionVars()
lockCtx := newLockCtx(seVars, seVars.LockWaitTimeout)
var lockKeyStats *execdetails.LockKeysDetails
ctx = context.WithValue(ctx, execdetails.LockKeysDetailCtxKey, &lockKeyStats)
startLocking := time.Now()
err = txn.LockKeys(ctx, lockCtx, keys...)
if lockKeyStats != nil {
seVars.StmtCtx.MergeLockKeysExecDetails(lockKeyStats)
}
if err == nil {
return nil
}
e, err = a.handlePessimisticLockError(ctx, err)
if err != nil {
if ErrDeadlock.Equal(err) {
metrics.StatementDeadlockDetectDuration.Observe(time.Since(startLocking).Seconds())
}
return err
}
}
}
// UpdateForUpdateTS updates the ForUpdateTS, if newForUpdateTS is 0, it obtain a new TS from PD.
func UpdateForUpdateTS(seCtx sessionctx.Context, newForUpdateTS uint64) error {
txn, err := seCtx.Txn(false)
if err != nil {
return err
}
if !txn.Valid() {
return errors.Trace(kv.ErrInvalidTxn)
}
if newForUpdateTS == 0 {
version, err := seCtx.GetStore().CurrentVersion()
if err != nil {
return err
}
newForUpdateTS = version.Ver
}
seCtx.GetSessionVars().TxnCtx.SetForUpdateTS(newForUpdateTS)
txn.SetOption(kv.SnapshotTS, seCtx.GetSessionVars().TxnCtx.GetForUpdateTS())
return nil
}
// handlePessimisticLockError updates TS and rebuild executor if the err is write conflict.
func (a *ExecStmt) handlePessimisticLockError(ctx context.Context, err error) (Executor, error) {
txnCtx := a.Ctx.GetSessionVars().TxnCtx
var newForUpdateTS uint64
if deadlock, ok := errors.Cause(err).(*tikv.ErrDeadlock); ok {
if !deadlock.IsRetryable {
return nil, ErrDeadlock
}
logutil.Logger(ctx).Info("single statement deadlock, retry statement",
zap.Uint64("txn", txnCtx.StartTS),
zap.Uint64("lockTS", deadlock.LockTs),
zap.Stringer("lockKey", kv.Key(deadlock.LockKey)),
zap.Uint64("deadlockKeyHash", deadlock.DeadlockKeyHash))
} else if terror.ErrorEqual(kv.ErrWriteConflict, err) {
errStr := err.Error()
conflictCommitTS := extractConflictCommitTS(errStr)
forUpdateTS := txnCtx.GetForUpdateTS()
logutil.Logger(ctx).Info("pessimistic write conflict, retry statement",
zap.Uint64("txn", txnCtx.StartTS),
zap.Uint64("forUpdateTS", forUpdateTS),
zap.String("err", errStr))
if conflictCommitTS > forUpdateTS {
newForUpdateTS = conflictCommitTS
}
} else {
// this branch if err not nil, always update forUpdateTS to avoid problem described below
// for nowait, when ErrLock happened, ErrLockAcquireFailAndNoWaitSet will be returned, and in the same txn
// the select for updateTs must be updated, otherwise there maybe rollback problem.
// begin; select for update key1(here ErrLocked or other errors(or max_execution_time like util),
// key1 lock not get and async rollback key1 is raised)
// select for update key1 again(this time lock succ(maybe lock released by others))
// the async rollback operation rollbacked the lock just acquired
if err != nil {
tsErr := UpdateForUpdateTS(a.Ctx, 0)
if tsErr != nil {
logutil.Logger(ctx).Warn("UpdateForUpdateTS failed", zap.Error(tsErr))
}
}
return nil, err
}
if a.retryCount >= config.GetGlobalConfig().PessimisticTxn.MaxRetryCount {
return nil, errors.New("pessimistic lock retry limit reached")
}
a.retryCount++
a.retryStartTime = time.Now()
err = UpdateForUpdateTS(a.Ctx, newForUpdateTS)
if err != nil {
return nil, err
}
e, err := a.buildExecutor()
if err != nil {
return nil, err
}
// Rollback the statement change before retry it.
a.Ctx.StmtRollback()
a.Ctx.GetSessionVars().StmtCtx.ResetForRetry()
a.Ctx.GetSessionVars().RetryInfo.ResetOffset()
if err = e.Open(ctx); err != nil {
return nil, err
}
return e, nil
}
func extractConflictCommitTS(errStr string) uint64 {
strs := strings.Split(errStr, "conflictCommitTS=")
if len(strs) != 2 {
return 0
}
tsPart := strs[1]
length := strings.IndexByte(tsPart, ',')
if length < 0 {
return 0
}
tsStr := tsPart[:length]
ts, err := strconv.ParseUint(tsStr, 10, 64)
if err != nil {
return 0
}
return ts
}
type pessimisticTxn interface {
kv.Transaction
// KeysNeedToLock returns the keys need to be locked.
KeysNeedToLock() ([]kv.Key, error)
}
// buildExecutor build a executor from plan, prepared statement may need additional procedure.
func (a *ExecStmt) buildExecutor() (Executor, error) {
ctx := a.Ctx
stmtCtx := ctx.GetSessionVars().StmtCtx
if _, ok := a.Plan.(*plannercore.Execute); !ok {
// Do not sync transaction for Execute statement, because the real optimization work is done in
// "ExecuteExec.Build".
useMaxTS, err := plannercore.IsPointGetWithPKOrUniqueKeyByAutoCommit(ctx, a.Plan)
if err != nil {
return nil, err
}
if useMaxTS {
logutil.BgLogger().Debug("init txnStartTS with MaxUint64", zap.Uint64("conn", ctx.GetSessionVars().ConnectionID), zap.String("text", a.Text))
err = ctx.InitTxnWithStartTS(math.MaxUint64)
} else if ctx.GetSessionVars().SnapshotTS != 0 {
if _, ok := a.Plan.(*plannercore.CheckTable); ok {
err = ctx.InitTxnWithStartTS(ctx.GetSessionVars().SnapshotTS)
}
}
if err != nil {
return nil, err
}
if stmtPri := stmtCtx.Priority; stmtPri == mysql.NoPriority {
switch {
case useMaxTS:
stmtCtx.Priority = kv.PriorityHigh
case a.LowerPriority:
stmtCtx.Priority = kv.PriorityLow
}
}
}
if _, ok := a.Plan.(*plannercore.Analyze); ok && ctx.GetSessionVars().InRestrictedSQL {
ctx.GetSessionVars().StmtCtx.Priority = kv.PriorityLow
}
b := newExecutorBuilder(ctx, a.InfoSchema)
e := b.build(a.Plan)
if b.err != nil {
return nil, errors.Trace(b.err)
}
// ExecuteExec is not a real Executor, we only use it to build another Executor from a prepared statement.
if executorExec, ok := e.(*ExecuteExec); ok {
err := executorExec.Build(b)
if err != nil {
return nil, err
}
a.Ctx.SetValue(sessionctx.QueryString, executorExec.stmt.Text())
a.OutputNames = executorExec.outputNames
a.isPreparedStmt = true
a.Plan = executorExec.plan
if executorExec.lowerPriority {
ctx.GetSessionVars().StmtCtx.Priority = kv.PriorityLow
}
e = executorExec.stmtExec
}
a.isSelectForUpdate = b.hasLock && (!stmtCtx.InDeleteStmt && !stmtCtx.InUpdateStmt && !stmtCtx.InInsertStmt)
return e, nil
}
// QueryReplacer replaces new line and tab for grep result including query string.
var QueryReplacer = strings.NewReplacer("\r", " ", "\n", " ", "\t", " ")
func (a *ExecStmt) logAudit() {
sessVars := a.Ctx.GetSessionVars()
if sessVars.InRestrictedSQL {
return
}
err := plugin.ForeachPlugin(plugin.Audit, func(p *plugin.Plugin) error {
audit := plugin.DeclareAuditManifest(p.Manifest)
if audit.OnGeneralEvent != nil {
cmd := mysql.Command2Str[byte(atomic.LoadUint32(&a.Ctx.GetSessionVars().CommandValue))]
ctx := context.WithValue(context.Background(), plugin.ExecStartTimeCtxKey, a.Ctx.GetSessionVars().StartTime)
audit.OnGeneralEvent(ctx, sessVars, plugin.Log, cmd)
}
return nil
})
if err != nil {
log.Error("log audit log failure", zap.Error(err))
}
}
// FormatSQL is used to format the original SQL, e.g. truncating long SQL, appending prepared arguments.
func FormatSQL(sql string, pps variable.PreparedParams) stringutil.StringerFunc {
return func() string {
cfg := config.GetGlobalConfig()
length := len(sql)
if maxQueryLen := atomic.LoadUint64(&cfg.Log.QueryLogMaxLen); uint64(length) > maxQueryLen {
sql = fmt.Sprintf("%.*q(len:%d)", maxQueryLen, sql, length)
}
return QueryReplacer.Replace(sql) + pps.String()
}
}
var (
sessionExecuteRunDurationInternal = metrics.SessionExecuteRunDuration.WithLabelValues(metrics.LblInternal)
sessionExecuteRunDurationGeneral = metrics.SessionExecuteRunDuration.WithLabelValues(metrics.LblGeneral)
)
// CloseRecordSet will finish the execution of current statement and do some record work
func (a *ExecStmt) CloseRecordSet(txnStartTS uint64, lastErr error) {
a.FinishExecuteStmt(txnStartTS, lastErr == nil, false)
a.logAudit()
// Detach the disk tracker from GlobalDiskUsageTracker after every execution
if stmtCtx := a.Ctx.GetSessionVars().StmtCtx; stmtCtx != nil && stmtCtx.DiskTracker != nil {
stmtCtx.DiskTracker.DetachFromGlobalTracker()
}
}
// FinishExecuteStmt is used to record some information after `ExecStmt` execution finished:
// 1. record slow log if needed.
// 2. record summary statement.
// 3. record execute duration metric.
// 4. update the `PrevStmt` in session variable.
func (a *ExecStmt) FinishExecuteStmt(txnTS uint64, succ bool, hasMoreResults bool) {
sessVars := a.Ctx.GetSessionVars()
execDetail := sessVars.StmtCtx.GetExecDetails()
// Attach commit/lockKeys runtime stats to executor runtime stats.
if (execDetail.CommitDetail != nil || execDetail.LockKeysDetail != nil) && sessVars.StmtCtx.RuntimeStatsColl != nil {
statsWithCommit := &execdetails.RuntimeStatsWithCommit{
Commit: execDetail.CommitDetail,
LockKeys: execDetail.LockKeysDetail,
}
sessVars.StmtCtx.RuntimeStatsColl.RegisterStats(a.Plan.ID(), statsWithCommit)
}
// `LowSlowQuery` and `SummaryStmt` must be called before recording `PrevStmt`.
a.LogSlowQuery(txnTS, succ, hasMoreResults)
a.SummaryStmt(succ)
prevStmt := a.GetTextToLog()
if sessVars.EnableRedactLog {
sessVars.PrevStmt = FormatSQL(prevStmt, nil)
} else {
pps := types.CloneRow(sessVars.PreparedParams)
sessVars.PrevStmt = FormatSQL(prevStmt, pps)
}
executeDuration := time.Since(sessVars.StartTime) - sessVars.DurationCompile
if sessVars.InRestrictedSQL {
sessionExecuteRunDurationInternal.Observe(executeDuration.Seconds())
} else {
sessionExecuteRunDurationGeneral.Observe(executeDuration.Seconds())
}
}
// LogSlowQuery is used to print the slow query in the log files.
func (a *ExecStmt) LogSlowQuery(txnTS uint64, succ bool, hasMoreResults bool) {
sessVars := a.Ctx.GetSessionVars()
level := log.GetLevel()
cfg := config.GetGlobalConfig()
costTime := time.Since(sessVars.StartTime) + sessVars.DurationParse
threshold := time.Duration(atomic.LoadUint64(&cfg.Log.SlowThreshold)) * time.Millisecond
enable := cfg.Log.EnableSlowLog
// if the level is Debug, or trace is enabled, print slow logs anyway
force := level <= zapcore.DebugLevel || trace.IsEnabled()
if (!enable || costTime < threshold) && !force {
return
}
var sql stringutil.StringerFunc
normalizedSQL, digest := sessVars.StmtCtx.SQLDigest()
if sessVars.EnableRedactLog {
sql = FormatSQL(normalizedSQL, nil)
} else if sensitiveStmt, ok := a.StmtNode.(ast.SensitiveStmtNode); ok {
sql = FormatSQL(sensitiveStmt.SecureText(), nil)
} else {
sql = FormatSQL(a.Text, sessVars.PreparedParams)
}
var tableIDs, indexNames string
if len(sessVars.StmtCtx.TableIDs) > 0 {
tableIDs = strings.Replace(fmt.Sprintf("%v", sessVars.StmtCtx.TableIDs), " ", ",", -1)
}
if len(sessVars.StmtCtx.IndexNames) > 0 {
indexNames = strings.Replace(fmt.Sprintf("%v", sessVars.StmtCtx.IndexNames), " ", ",", -1)
}
var stmtDetail execdetails.StmtExecDetails
stmtDetailRaw := a.GoCtx.Value(execdetails.StmtExecDetailKey)
if stmtDetailRaw != nil {
stmtDetail = *(stmtDetailRaw.(*execdetails.StmtExecDetails))
}
execDetail := sessVars.StmtCtx.GetExecDetails()
copTaskInfo := sessVars.StmtCtx.CopTasksDetails()
statsInfos := plannercore.GetStatsInfo(a.Plan)
memMax := sessVars.StmtCtx.MemTracker.MaxConsumed()
diskMax := sessVars.StmtCtx.DiskTracker.MaxConsumed()
_, planDigest := getPlanDigest(a.Ctx, a.Plan)
slowItems := &variable.SlowQueryLogItems{
TxnTS: txnTS,
SQL: sql.String(),
Digest: digest,
TimeTotal: costTime,
TimeParse: sessVars.DurationParse,
TimeCompile: sessVars.DurationCompile,
IndexNames: indexNames,
StatsInfos: statsInfos,
CopTasks: copTaskInfo,
ExecDetail: execDetail,
MemMax: memMax,
DiskMax: diskMax,
Succ: succ,
Plan: getPlanTree(a.Ctx, a.Plan),
PlanDigest: planDigest,
Prepared: a.isPreparedStmt,
HasMoreResults: hasMoreResults,
PlanFromCache: sessVars.FoundInPlanCache,
KVTotal: time.Duration(atomic.LoadInt64(&stmtDetail.WaitKVRespDuration)),
PDTotal: time.Duration(atomic.LoadInt64(&stmtDetail.WaitPDRespDuration)),
BackoffTotal: time.Duration(atomic.LoadInt64(&stmtDetail.BackoffDuration)),
WriteSQLRespTotal: stmtDetail.WriteSQLRespDuration,
RewriteInfo: sessVars.RewritePhaseInfo,
ExecRetryCount: a.retryCount,
}
if a.retryCount > 0 {
slowItems.ExecRetryTime = costTime - sessVars.DurationParse - sessVars.DurationCompile - time.Since(a.retryStartTime)
}
if _, ok := a.StmtNode.(*ast.CommitStmt); ok {
slowItems.PrevStmt = sessVars.PrevStmt.String()
}
if trace.IsEnabled() {
trace.Log(a.GoCtx, "details", sessVars.SlowLogFormat(slowItems))
}
if costTime < threshold {
logutil.SlowQueryLogger.Debug(sessVars.SlowLogFormat(slowItems))
} else {
logutil.SlowQueryLogger.Warn(sessVars.SlowLogFormat(slowItems))
metrics.TotalQueryProcHistogram.Observe(costTime.Seconds())
metrics.TotalCopProcHistogram.Observe(execDetail.ProcessTime.Seconds())
metrics.TotalCopWaitHistogram.Observe(execDetail.WaitTime.Seconds())
var userString string
if sessVars.User != nil {
userString = sessVars.User.String()
}
domain.GetDomain(a.Ctx).LogSlowQuery(&domain.SlowQueryInfo{
SQL: sql.String(),
Digest: digest,
Start: sessVars.StartTime,
Duration: costTime,
Detail: sessVars.StmtCtx.GetExecDetails(),
Succ: succ,
ConnID: sessVars.ConnectionID,
TxnTS: txnTS,
User: userString,
DB: sessVars.CurrentDB,
TableIDs: tableIDs,
IndexNames: indexNames,
Internal: sessVars.InRestrictedSQL,
})
}
}
// getPlanTree will try to get the select plan tree if the plan is select or the select plan of delete/update/insert statement.
func getPlanTree(sctx sessionctx.Context, p plannercore.Plan) string {
cfg := config.GetGlobalConfig()
if atomic.LoadUint32(&cfg.Log.RecordPlanInSlowLog) == 0 {
return ""
}
planTree := getEncodedPlan(sctx, p)
if len(planTree) == 0 {
return planTree
}
return variable.SlowLogPlanPrefix + planTree + variable.SlowLogPlanSuffix
}
// getPlanDigest will try to get the select plan tree if the plan is select or the select plan of delete/update/insert statement.
func getPlanDigest(sctx sessionctx.Context, p plannercore.Plan) (normalized, planDigest string) {
normalized, planDigest = sctx.GetSessionVars().StmtCtx.GetPlanDigest()
if len(normalized) > 0 {
return
}
normalized, planDigest = plannercore.NormalizePlan(p)
sctx.GetSessionVars().StmtCtx.SetPlanDigest(normalized, planDigest)
return
}
// getEncodedPlan uses to get encoded plan.
func getEncodedPlan(sctx sessionctx.Context, p plannercore.Plan) (encodedPlan string) {
encodedPlan = sctx.GetSessionVars().StmtCtx.GetEncodedPlan()
if len(encodedPlan) > 0 {
return
}
encodedPlan = plannercore.EncodePlan(p)
sctx.GetSessionVars().StmtCtx.SetEncodedPlan(encodedPlan)
return
}
// SummaryStmt collects statements for information_schema.statements_summary
func (a *ExecStmt) SummaryStmt(succ bool) {
sessVars := a.Ctx.GetSessionVars()
var userString string
if sessVars.User != nil {
userString = sessVars.User.Username
}
// Internal SQLs must also be recorded to keep the consistency of `PrevStmt` and `PrevStmtDigest`.
if !stmtsummary.StmtSummaryByDigestMap.Enabled() || ((sessVars.InRestrictedSQL || len(userString) == 0) && !stmtsummary.StmtSummaryByDigestMap.EnabledInternal()) {
sessVars.SetPrevStmtDigest("")
return
}
// Ignore `PREPARE` statements, but record `EXECUTE` statements.
if _, ok := a.StmtNode.(*ast.PrepareStmt); ok {
return
}
stmtCtx := sessVars.StmtCtx
normalizedSQL, digest := stmtCtx.SQLDigest()
costTime := time.Since(sessVars.StartTime) + sessVars.DurationParse
var prevSQL, prevSQLDigest string
if _, ok := a.StmtNode.(*ast.CommitStmt); ok {
// If prevSQLDigest is not recorded, it means this `commit` is the first SQL once stmt summary is enabled,
// so it's OK just to ignore it.
if prevSQLDigest = sessVars.GetPrevStmtDigest(); len(prevSQLDigest) == 0 {
return
}
prevSQL = sessVars.PrevStmt.String()
}
sessVars.SetPrevStmtDigest(digest)
// No need to encode every time, so encode lazily.
planGenerator := func() string {
return getEncodedPlan(a.Ctx, a.Plan)
}
// Generating plan digest is slow, only generate it once if it's 'Point_Get'.
// If it's a point get, different SQLs leads to different plans, so SQL digest
// is enough to distinguish different plans in this case.
var planDigest string
var planDigestGen func() string
if a.Plan.TP() == plancodec.TypePointGet {
planDigestGen = func() string {
_, planDigest := getPlanDigest(a.Ctx, a.Plan)
return planDigest
}
} else {
_, planDigest = getPlanDigest(a.Ctx, a.Plan)
}
execDetail := stmtCtx.GetExecDetails()
copTaskInfo := stmtCtx.CopTasksDetails()
memMax := stmtCtx.MemTracker.MaxConsumed()
diskMax := stmtCtx.DiskTracker.MaxConsumed()
sql := a.GetTextToLog()
var stmtDetail execdetails.StmtExecDetails
stmtDetailRaw := a.GoCtx.Value(execdetails.StmtExecDetailKey)
if stmtDetailRaw != nil {
stmtDetail = *(stmtDetailRaw.(*execdetails.StmtExecDetails))
}
stmtExecInfo := &stmtsummary.StmtExecInfo{
SchemaName: strings.ToLower(sessVars.CurrentDB),
OriginalSQL: sql,
NormalizedSQL: normalizedSQL,
Digest: digest,
PrevSQL: prevSQL,
PrevSQLDigest: prevSQLDigest,
PlanGenerator: planGenerator,
PlanDigest: planDigest,
PlanDigestGen: planDigestGen,
User: userString,
TotalLatency: costTime,
ParseLatency: sessVars.DurationParse,
CompileLatency: sessVars.DurationCompile,
StmtCtx: stmtCtx,
CopTasks: copTaskInfo,
ExecDetail: &execDetail,
MemMax: memMax,
DiskMax: diskMax,
StartTime: sessVars.StartTime,
IsInternal: sessVars.InRestrictedSQL,
Succeed: succ,
PlanInCache: sessVars.FoundInPlanCache,
ExecRetryCount: a.retryCount,
StmtExecDetails: stmtDetail,
Prepared: a.isPreparedStmt,
}
if a.retryCount > 0 {
stmtExecInfo.ExecRetryTime = costTime - sessVars.DurationParse - sessVars.DurationCompile - time.Since(a.retryStartTime)
}
stmtsummary.StmtSummaryByDigestMap.AddStatement(stmtExecInfo)
}
// GetTextToLog return the query text to log.
func (a *ExecStmt) GetTextToLog() string {
var sql string
if a.Ctx.GetSessionVars().EnableRedactLog {
sql, _ = a.Ctx.GetSessionVars().StmtCtx.SQLDigest()
} else if sensitiveStmt, ok := a.StmtNode.(ast.SensitiveStmtNode); ok {
sql = sensitiveStmt.SecureText()
} else {
sql = a.Text
}
return sql
}