session: rename circuit breaker sysvar

pkg/domain/domain_sysvars.go

@@ -47,7 +47,7 @@ func (do *Domain) initDomainSysVars() {
 
 	variable.ChangeSchemaCacheSize = do.isSyncer.ChangeSchemaCacheSize
 
-	variable.ChangePDMetadataCircuitBreakerErrorRateThresholdPct = changePDMetadataCircuitBreakerErrorRateThresholdPct
+	variable.ChangePDMetadataCircuitBreakerErrorRateThresholdRatio = changePDMetadataCircuitBreakerErrorRateThresholdRatio
 }
 
 // setStatsCacheCapacity sets statsCache cap
@@ -149,8 +149,8 @@ func (do *Domain) getExternalTimestamp(ctx context.Context) (uint64, error) {
 	return do.store.GetOracle().GetExternalTimestamp(ctx)
 }
 
-func changePDMetadataCircuitBreakerErrorRateThresholdPct(errorRatePct uint32) {
+func changePDMetadataCircuitBreakerErrorRateThresholdRatio(errorRateRatio uint32) {
 	tikv.ChangePDRegionMetaCircuitBreakerSettings(func(config *circuitbreaker.Settings) {
-		config.ErrorRateThresholdPct = errorRatePct
+		config.ErrorRateThresholdPct = errorRateRatio
 	})
 }

pkg/sessionctx/vardef/tidb_vars.go

@@ -1258,9 +1258,9 @@ const (
 	// TiDBTSOClientRPCMode controls how the TSO client performs the TSO RPC requests. It internally controls the
 	// concurrency of the RPC. This variable provides an approach to tune the latency of getting timestamps from PD.
 	TiDBTSOClientRPCMode = "tidb_tso_client_rpc_mode"
-	// TiDBCircuitBreakerPDMetadataErrorRateThresholdPct variable is used to set percent of errors to trip the circuit breaker for get region calls to PD
+	// TiDBCircuitBreakerPDMetadataErrorRateThresholdRatio variable is used to set ratio of errors to trip the circuit breaker for get region calls to PD
 	// https://github.com/tikv/rfcs/blob/master/text/0115-circuit-breaker.md
-	TiDBCircuitBreakerPDMetadataErrorRateThresholdPct = "tidb_cb_pd_metadata_error_rate_threshold_pct"
+	TiDBCircuitBreakerPDMetadataErrorRateThresholdRatio = "tidb_cb_pd_metadata_error_rate_threshold_ratio"
 
 	// TiDBEnableTSValidation controls whether to enable the timestamp validation in client-go.
 	TiDBEnableTSValidation = "tidb_enable_ts_validation"
@@ -1658,7 +1658,7 @@ const (
 	DefOptEnableProjectionPushDown                    = true
 	DefTiDBEnableSharedLockPromotion                  = false
 	DefTiDBTSOClientRPCMode                           = TSOClientRPCModeDefault
-	DefTiDBCircuitBreakerPDMetaErrorRatePct           = 0.0
+	DefTiDBCircuitBreakerPDMetaErrorRateRatio         = 0.0
 	DefTiDBAccelerateUserCreationUpdate               = false
 	DefTiDBEnableTSValidation                         = true
 	DefTiDBLoadBindingTimeout                         = 200
@@ -1790,7 +1790,7 @@ var (
 	SchemaCacheSizeOriginText    = atomic.NewString(strconv.Itoa(DefTiDBSchemaCacheSize))
 	AccelerateUserCreationUpdate = atomic.NewBool(DefTiDBAccelerateUserCreationUpdate)
 
-	CircuitBreakerPDMetadataErrorRateThresholdPct = atomic.NewFloat64(0.0)
+	CircuitBreakerPDMetadataErrorRateThresholdRatio = atomic.NewFloat64(0.0)
 )
 
 func serverMemoryLimitDefaultValue() string {

pkg/sessionctx/variable/sysvar.go

@@ -3563,19 +3563,19 @@ var defaultSysVars = []*SysVar{
 			return (*SetPDClientDynamicOption.Load())(vardef.TiDBTSOClientRPCMode, val)
 		},
 	},
-	{Scope: vardef.ScopeGlobal, Name: vardef.TiDBCircuitBreakerPDMetadataErrorRateThresholdPct, Value: strconv.FormatFloat(vardef.DefTiDBCircuitBreakerPDMetaErrorRatePct, 'f', -1, 64),
+	{Scope: vardef.ScopeGlobal, Name: vardef.TiDBCircuitBreakerPDMetadataErrorRateThresholdRatio, Value: strconv.FormatFloat(vardef.DefTiDBCircuitBreakerPDMetaErrorRateRatio, 'f', -1, 64),
 		Type: vardef.TypeFloat, MinValue: 0, MaxValue: 1,
 		GetGlobal: func(_ context.Context, s *SessionVars) (string, error) {
-			return strconv.FormatFloat(vardef.CircuitBreakerPDMetadataErrorRateThresholdPct.Load(), 'f', -1, 64), nil
+			return strconv.FormatFloat(vardef.CircuitBreakerPDMetadataErrorRateThresholdRatio.Load(), 'f', -1, 64), nil
 		},
 		SetGlobal: func(_ context.Context, s *SessionVars, val string) error {
-			v := tidbOptFloat64(val, vardef.DefTiDBCircuitBreakerPDMetaErrorRatePct)
+			v := tidbOptFloat64(val, vardef.DefTiDBCircuitBreakerPDMetaErrorRateRatio)
 			if v < 0 || v > 1 {
-				return errors.Errorf("invalid tidb_cb_pd_metadata_error_rate_threshold_pct value %s", val)
+				return errors.Errorf("invalid tidb_cb_pd_metadata_error_rate_threshold_ratio value %s", val)
 			}
-			vardef.CircuitBreakerPDMetadataErrorRateThresholdPct.Store(v)
-			if ChangePDMetadataCircuitBreakerErrorRateThresholdPct != nil {
-				ChangePDMetadataCircuitBreakerErrorRateThresholdPct(uint32(v * 100))
+			vardef.CircuitBreakerPDMetadataErrorRateThresholdRatio.Store(v)
+			if ChangePDMetadataCircuitBreakerErrorRateThresholdRatio != nil {
+				ChangePDMetadataCircuitBreakerErrorRateThresholdRatio(uint32(v * 100))
 			}
 			return nil
 		},

pkg/sessionctx/variable/sysvar_test.go

@@ -1761,23 +1761,23 @@ func TestTiDBSchemaCacheSize(t *testing.T) {
 	require.Error(t, err)
 }
 
-func TestTiDBCircuitBreakerPDMetadataErrorRateThresholdPct(t *testing.T) {
-	sv := GetSysVar(vardef.TiDBCircuitBreakerPDMetadataErrorRateThresholdPct)
+func TestTiDBCircuitBreakerPDMetadataErrorRateThresholdRatio(t *testing.T) {
+	sv := GetSysVar(vardef.TiDBCircuitBreakerPDMetadataErrorRateThresholdRatio)
 	vars := NewSessionVars(nil)
 
 	// Too low, will get raised to the min value
 	val, err := sv.Validate(vars, "-1", vardef.ScopeGlobal)
 	require.NoError(t, err)
-	require.Equal(t, strconv.FormatInt(GetSysVar(vardef.TiDBCircuitBreakerPDMetadataErrorRateThresholdPct).MinValue, 10), val)
+	require.Equal(t, strconv.FormatInt(GetSysVar(vardef.TiDBCircuitBreakerPDMetadataErrorRateThresholdRatio).MinValue, 10), val)
 	warn := vars.StmtCtx.GetWarnings()[0].Err
-	require.Equal(t, "[variable:1292]Truncated incorrect tidb_cb_pd_metadata_error_rate_threshold_pct value: '-1'", warn.Error())
+	require.Equal(t, "[variable:1292]Truncated incorrect tidb_cb_pd_metadata_error_rate_threshold_ratio value: '-1'", warn.Error())
 
 	// Too high, will get lowered to the max value
 	val, err = sv.Validate(vars, "1.1", vardef.ScopeGlobal)
 	require.NoError(t, err)
-	require.Equal(t, strconv.FormatUint(GetSysVar(vardef.TiDBCircuitBreakerPDMetadataErrorRateThresholdPct).MaxValue, 10), val)
+	require.Equal(t, strconv.FormatUint(GetSysVar(vardef.TiDBCircuitBreakerPDMetadataErrorRateThresholdRatio).MaxValue, 10), val)
 	warn = vars.StmtCtx.GetWarnings()[1].Err
-	require.Equal(t, "[variable:1292]Truncated incorrect tidb_cb_pd_metadata_error_rate_threshold_pct value: '1.1'", warn.Error())
+	require.Equal(t, "[variable:1292]Truncated incorrect tidb_cb_pd_metadata_error_rate_threshold_ratio value: '1.1'", warn.Error())
 
 	// valid
 	val, err = sv.Validate(vars, "0.9", vardef.ScopeGlobal)

pkg/sessionctx/variable/tidb_vars.go

@@ -54,8 +54,8 @@ var (
 	EnableStatsOwner func() error = nil
 	// DisableStatsOwner is the func registered by stats to disable running stats in this instance.
 	DisableStatsOwner func() error = nil
-	// ChangePDMetadataCircuitBreakerErrorRateThresholdPct changes the error rate threshold of the PD metadata circuit breaker.
-	ChangePDMetadataCircuitBreakerErrorRateThresholdPct func(uint32) = nil
+	// ChangePDMetadataCircuitBreakerErrorRateThresholdRatio changes the error rate threshold of the PD metadata circuit breaker.
+	ChangePDMetadataCircuitBreakerErrorRateThresholdRatio func(uint32) = nil
 )
 
 // Hooks functions for Cluster Resource Control.