*: add global variable tidb_slow_log_masking to control masking slow log query (#17637)

executor/adapter.go

@@ -811,7 +811,13 @@ func (a *ExecStmt) LogSlowQuery(txnTS uint64, succ bool, hasMoreResults bool) {
 	if (!enable || costTime < threshold) && level > zapcore.DebugLevel {
 		return
 	}
-	sql := FormatSQL(a.Text, sessVars.PreparedParams)
+	var sql stringutil.StringerFunc
+	normalizedSQL, digest := sessVars.StmtCtx.SQLDigest()
+	if sessVars.EnableSlowLogMasking {
+		sql = FormatSQL(normalizedSQL, nil)
+	} else {
+		sql = FormatSQL(a.Text, sessVars.PreparedParams)
+	}
 
 	var tableIDs, indexNames string
 	if len(sessVars.StmtCtx.TableIDs) > 0 {
@@ -824,7 +830,6 @@ func (a *ExecStmt) LogSlowQuery(txnTS uint64, succ bool, hasMoreResults bool) {
 	copTaskInfo := sessVars.StmtCtx.CopTasksDetails()
 	statsInfos := plannercore.GetStatsInfo(a.Plan)
 	memMax := sessVars.StmtCtx.MemTracker.MaxConsumed()
-	_, digest := sessVars.StmtCtx.SQLDigest()
 	_, planDigest := getPlanDigest(a.Ctx, a.Plan)
 	slowItems := &variable.SlowQueryLogItems{
 		TxnTS:          txnTS,

executor/set_test.go

@@ -416,6 +416,17 @@ func (s *testSuite5) TestSetVar(c *C) {
 	c.Assert(err, NotNil)
 	c.Assert(err.Error(), Equals, "tidb_metric_query_range_duration(9) cannot be smaller than 10 or larger than 216000")
 	tk.MustQuery("select @@session.tidb_metric_query_range_duration;").Check(testkit.Rows("120"))
+
+	// test for tidb_slow_log_masking
+	tk.MustQuery(`select @@global.tidb_slow_log_masking;`).Check(testkit.Rows("0"))
+	tk.MustExec("set global tidb_slow_log_masking = 1")
+	tk.MustQuery(`select @@global.tidb_slow_log_masking;`).Check(testkit.Rows("1"))
+	tk.MustExec("set global tidb_slow_log_masking = 0")
+	tk.MustQuery(`select @@global.tidb_slow_log_masking;`).Check(testkit.Rows("0"))
+	_, err = tk.Exec("set session tidb_slow_log_masking = 0")
+	c.Assert(err, NotNil)
+	_, err = tk.Exec(`select @@session.tidb_slow_log_masking;`)
+	c.Assert(err, NotNil)
 }
 
 func (s *testSuite5) TestSetCharset(c *C) {

session/session.go

@@ -1959,6 +1959,7 @@ var builtinGlobalVariable = []string{
 	variable.TiDBEvolvePlanBaselines,
 	variable.TiDBIsolationReadEngines,
 	variable.TiDBStoreLimit,
+	variable.TiDBSlowLogMasking,
 }
 
 var (

sessionctx/variable/session.go

@@ -602,6 +602,9 @@ type SessionVars struct {
 
 	// SelectLimit limits the max counts of select statement's output
 	SelectLimit uint64
+
+	// EnableSlowLogMasking indicates that whether masking the query data when log slow query.
+	EnableSlowLogMasking bool
 }
 
 // PreparedParams contains the parameters of the current prepared statement when executing it.
@@ -690,6 +693,7 @@ func NewSessionVars() *SessionVars {
 		PrevFoundInPlanCache:        DefTiDBFoundInPlanCache,
 		FoundInPlanCache:            DefTiDBFoundInPlanCache,
 		SelectLimit:                 math.MaxUint64,
+		EnableSlowLogMasking:        DefTiDBSlowLogMasking,
 	}
 	vars.KVVars = kv.NewVariables(&vars.Killed)
 	vars.Concurrency = Concurrency{
@@ -1276,6 +1280,8 @@ func (s *SessionVars) SetSystemVar(name string, val string) error {
 			return errors.Trace(err)
 		}
 		s.SelectLimit = result
+	case TiDBSlowLogMasking:
+		s.EnableSlowLogMasking = TiDBOptOn(val)
 	}
 	s.systems[name] = val
 	return nil

sessionctx/variable/sysvar.go

@@ -720,6 +720,7 @@ var defaultSysVars = []*SysVar{
 	{ScopeSession, TiDBQueryLogMaxLen, strconv.Itoa(logutil.DefaultQueryLogMaxLen)},
 	{ScopeSession, TiDBCheckMb4ValueInUTF8, BoolToIntStr(config.GetGlobalConfig().CheckMb4ValueInUTF8)},
 	{ScopeSession, TiDBFoundInPlanCache, BoolToIntStr(DefTiDBFoundInPlanCache)},
+	{ScopeGlobal, TiDBSlowLogMasking, BoolToIntStr(DefTiDBSlowLogMasking)},
 }
 
 // SynonymsSysVariables is synonyms of system variables.

sessionctx/variable/tidb_vars.go

@@ -390,6 +390,9 @@ const (
 
 	// TiDBMetricSchemaRangeDuration indicates the range duration when query metric schema.
 	TiDBMetricSchemaRangeDuration = "tidb_metric_query_range_duration"
+
+	// TiDBSlowLogMasking indicates that whether masking the query data when log slow query.
+	TiDBSlowLogMasking = "tidb_slow_log_masking"
 )
 
 // Default TiDB system variable values.
@@ -483,6 +486,7 @@ const (
 	DefTiDBMetricSchemaStep            = 60 // 60s
 	DefTiDBMetricSchemaRangeDuration   = 60 // 60s
 	DefTiDBFoundInPlanCache            = false
+	DefTiDBSlowLogMasking              = false
 )
 
 // Process global variables.