executor: add config EnableCollectExecutionInfo (pingcap#15493)

config/config.go

@@ -132,6 +132,8 @@ type Config struct {
 	// EnableDynamicConfig enables the TiDB to fetch configs from PD and update itself during runtime.
 	// see https://github.com/pingcap/tidb/pull/13660 for more details.
 	EnableDynamicConfig bool `toml:"enable-dynamic-config" json:"enable-dynamic-config"`
+	// EnableCollectExecutionInfo enables the TiDB to collect execution info.
+	EnableCollectExecutionInfo bool `toml:"enable-collect-execution-info" json:"enable-collect-execution-info"`
 }
 
 // UpdateTempStoragePath is to update the `TempStoragePath` if port/statusPort was changed
@@ -665,7 +667,8 @@ var defaultConf = Config{
 		AllowAutoRandom:       false,
 		AllowsExpressionIndex: false,
 	},
-	EnableDynamicConfig: false,
+	EnableDynamicConfig:        false,
+	EnableCollectExecutionInfo: false,
 }
 
 var (

executor/builder.go

@@ -31,6 +31,7 @@ import (
 	"github.com/pingcap/parser/ast"
 	"github.com/pingcap/parser/model"
 	"github.com/pingcap/parser/mysql"
+	"github.com/pingcap/tidb/config"
 	"github.com/pingcap/tidb/distsql"
 	"github.com/pingcap/tidb/domain"
 	"github.com/pingcap/tidb/executor/aggfuncs"
@@ -95,6 +96,9 @@ type MockPhysicalPlan interface {
 }
 
 func (b *executorBuilder) build(p plannercore.Plan) Executor {
+	if config.GetGlobalConfig().EnableCollectExecutionInfo && b.ctx.GetSessionVars().StmtCtx.RuntimeStatsColl == nil {
+		b.ctx.GetSessionVars().StmtCtx.RuntimeStatsColl = execdetails.NewRuntimeStatsColl()
+	}
 	switch v := p.(type) {
 	case nil:
 		return nil
@@ -879,7 +883,9 @@ func (b *executorBuilder) buildExplain(v *plannercore.Explain) Executor {
 		explain:      v,
 	}
 	if v.Analyze {
-		b.ctx.GetSessionVars().StmtCtx.RuntimeStatsColl = execdetails.NewRuntimeStatsColl()
+		if b.ctx.GetSessionVars().StmtCtx.RuntimeStatsColl == nil {
+			b.ctx.GetSessionVars().StmtCtx.RuntimeStatsColl = execdetails.NewRuntimeStatsColl()
+		}
 		explainExec.analyzeExec = b.build(v.TargetPlan)
 	}
 	return explainExec
@@ -1986,6 +1992,10 @@ func (b *executorBuilder) constructDAGReq(plans []plannercore.PhysicalPlan) (dag
 	dagReq = &tipb.DAGRequest{}
 	dagReq.TimeZoneName, dagReq.TimeZoneOffset = timeutil.Zone(b.ctx.GetSessionVars().Location())
 	sc := b.ctx.GetSessionVars().StmtCtx
+	if sc.RuntimeStatsColl != nil {
+		collExec := true
+		dagReq.CollectExecutionSummaries = &collExec
+	}
 	dagReq.Flags = sc.PushDownFlags()
 	dagReq.Executors, streaming, err = constructDistExec(b.ctx, plans)
 
@@ -2656,10 +2666,6 @@ func (builder *dataReaderBuilder) buildTableReaderForIndexJoin(ctx context.Conte
 }
 
 func (builder *dataReaderBuilder) buildTableReaderFromHandles(ctx context.Context, e *TableReaderExecutor, handles []int64) (Executor, error) {
-	if e.runtimeStats != nil && e.dagPB.CollectExecutionSummaries == nil {
-		colExec := true
-		e.dagPB.CollectExecutionSummaries = &colExec
-	}
 	startTS, err := builder.getSnapshotTS()
 	if err != nil {
 		return nil, err

executor/join.go

@@ -139,7 +139,9 @@ func (e *HashJoinExec) Close() error {
 	if e.runtimeStats != nil {
 		concurrency := cap(e.joiners)
 		e.runtimeStats.SetConcurrencyInfo("Concurrency", concurrency)
-		e.runtimeStats.SetAdditionalInfo(e.rowContainer.stat.String())
+		if e.rowContainer != nil {
+			e.runtimeStats.SetAdditionalInfo(e.rowContainer.stat.String())
+		}
 	}
 	err := e.baseExecutor.Close()
 	return err

sessionctx/variable/session.go

@@ -1272,6 +1272,13 @@ func (s *SessionVars) SetSystemVar(name string, val string) error {
 		} else {
 			s.StmtCtx.AppendWarning(errors.Errorf("cannot update %s when enabling dynamic configs", TiDBCheckMb4ValueInUTF8))
 		}
+	case TiDBEnableCollectExecutionInfo:
+		conf := config.GetGlobalConfig()
+		if !conf.EnableDynamicConfig {
+			config.GetGlobalConfig().EnableCollectExecutionInfo = TiDBOptOn(val)
+		} else {
+			s.StmtCtx.AppendWarning(errors.Errorf("cannot update %s when enabling dynamic configs", TiDBEnableCollectExecutionInfo))
+		}
 	}
 	s.systems[name] = val
 	return nil

sessionctx/variable/sysvar.go

@@ -718,6 +718,7 @@ var defaultSysVars = []*SysVar{
 	{ScopeSession, TiDBEnableSlowLog, BoolToIntStr(logutil.DefaultTiDBEnableSlowLog)},
 	{ScopeSession, TiDBQueryLogMaxLen, strconv.Itoa(logutil.DefaultQueryLogMaxLen)},
 	{ScopeSession, TiDBCheckMb4ValueInUTF8, BoolToIntStr(config.GetGlobalConfig().CheckMb4ValueInUTF8)},
+	{ScopeSession, TiDBEnableCollectExecutionInfo, BoolToIntStr(logutil.DefaultTiDBEnableSlowLog)},
 }
 
 // SynonymsSysVariables is synonyms of system variables.

sessionctx/variable/tidb_vars.go

@@ -388,6 +388,9 @@ const (
 
 	// TiDBMetricSchemaRangeDuration indicates the range duration when query metric schema.
 	TiDBMetricSchemaRangeDuration = "tidb_metric_query_range_duration"
+
+	// TiDBEnableCollectExecutionInfo indicates that whether execution info is collected.
+	TiDBEnableCollectExecutionInfo = "tidb_enable_collect_execution_info"
 )
 
 // Default TiDB system variable values.
@@ -481,6 +484,7 @@ const (
 	DefTiDBStoreLimit                  = 0
 	DefTiDBMetricSchemaStep            = 60 // 60s
 	DefTiDBMetricSchemaRangeDuration   = 60 // 60s
+	DefTidbEnableCollectExecutionInfo  = false
 )
 
 // Process global variables.

sessionctx/variable/varsutil.go

@@ -152,6 +152,8 @@ func GetSessionOnlySysVars(s *SessionVars, key string) (string, bool, error) {
 		return BoolToIntStr(config.GetGlobalConfig().CheckMb4ValueInUTF8), true, nil
 	case TiDBCapturePlanBaseline:
 		return CapturePlanBaseline.GetVal(), true, nil
+	case TiDBEnableCollectExecutionInfo:
+		return BoolToIntStr(config.GetGlobalConfig().EnableCollectExecutionInfo), true, nil
 	}
 	sVal, ok := s.GetSystemVar(key)
 	if ok {
@@ -417,7 +419,8 @@ func ValidateSetSystemVar(vars *SessionVars, name string, value string) (string,
 		TiDBBatchDelete, TiDBBatchCommit, TiDBEnableCascadesPlanner, TiDBEnableWindowFunction, TiDBPProfSQLCPU,
 		TiDBLowResolutionTSO, TiDBEnableIndexMerge, TiDBEnableNoopFuncs,
 		TiDBCheckMb4ValueInUTF8, TiDBEnableSlowLog, TiDBRecordPlanInSlowLog,
-		TiDBScatterRegion, TiDBGeneralLog, TiDBConstraintCheckInPlace, TiDBEnableVectorizedExpression:
+		TiDBScatterRegion, TiDBGeneralLog, TiDBConstraintCheckInPlace, TiDBEnableVectorizedExpression,
+		TiDBEnableCollectExecutionInfo:
 		fallthrough
 	case GeneralLog, AvoidTemporalUpgrade, BigTables, CheckProxyUsers, LogBin,
 		CoreFile, EndMakersInJSON, SQLLogBin, OfflineMode, PseudoSlaveMode, LowPriorityUpdates,