config: completely remove the deprecated field from the PD server config

server/config/config.go

@@ -18,7 +18,6 @@
 	"crypto/tls"
 	"encoding/json"
 	"fmt"
-	"math"
 	"net/url"
 	"os"
 	"path/filepath"
@@ -507,9 +506,6 @@
 	MetricStorage string `toml:"metric-storage" json:"metric-storage"`
 	// There are some values supported: "auto", "none", or a specific address, default: "auto"
 	DashboardAddress string `toml:"dashboard-address" json:"dashboard-address"`
-	// TraceRegionFlow the option to update flow information of regions.
-	// WARN: TraceRegionFlow is deprecated.
-	TraceRegionFlow bool `toml:"trace-region-flow" json:"trace-region-flow,string,omitempty"`
 	// FlowRoundByDigit used to discretization processing flow information.
 	FlowRoundByDigit int `toml:"flow-round-by-digit" json:"flow-round-by-digit"`
 	// MinResolvedTSPersistenceInterval is the interval to save the min resolved ts.
@@ -573,37 +569,23 @@
 	} else if c.GCTunerThreshold > maxGCTunerThreshold {
 		c.GCTunerThreshold = maxGCTunerThreshold
 	}
-	if err := c.migrateConfigurationFromFile(meta); err != nil {
+	if err := migrateConfigurationFromFile(meta); err != nil {
 		return err
 	}
 	return c.Validate()
 }
 
-func (c *PDServerConfig) migrateConfigurationFromFile(meta *configutil.ConfigMetaData) error {
+func migrateConfigurationFromFile(meta *configutil.ConfigMetaData) error {
 	oldName, newName := "trace-region-flow", "flow-round-by-digit"
-	defineOld, defineNew := meta.IsDefined(oldName), meta.IsDefined(newName)
+	defineOld := meta.IsDefined(oldName)
 	switch {
-	case defineOld && defineNew:
-		if c.TraceRegionFlow && (c.FlowRoundByDigit == defaultFlowRoundByDigit) {
-			return errors.Errorf("config item %s and %s(deprecated) are conflict", newName, oldName)
-		}
-	case defineOld && !defineNew:
-		if !c.TraceRegionFlow {
-			c.FlowRoundByDigit = math.MaxInt8
-		}
+	case defineOld:
+		return errors.Errorf("config item %s and %s(deprecated) are conflict", newName, oldName)
+	default:
 	}
 	return nil
 }
 
-// MigrateDeprecatedFlags updates new flags according to deprecated flags.
-func (c *PDServerConfig) MigrateDeprecatedFlags() {
-	if !c.TraceRegionFlow {
-		c.FlowRoundByDigit = math.MaxInt8
-	}
-	// json omity the false. next time will not persist to the kv.
-	c.TraceRegionFlow = false
-}
-
 // Clone returns a cloned PD server config.
 func (c *PDServerConfig) Clone() *PDServerConfig {
 	runtimeServices := append(c.RuntimeServices[:0:0], c.RuntimeServices...)

server/config/config_test.go

@@ -277,7 +277,7 @@ func TestMigrateFlags(t *testing.T) {
 	}
 	cfg, err := load(`
 [pd-server]
-trace-region-flow = false
+flow-round-by-digit = 127
 [schedule]
 disable-remove-down-replica = true
 enable-make-up-replica = false

server/config/persist_options.go

@@ -817,7 +817,6 @@ func (o *PersistOptions) Reload(storage endpoint.ConfigStorage) error {
 	adjustScheduleCfg(&cfg.Schedule)
 	// Some fields may not be stored in the storage, we need to calculate them manually.
 	cfg.StoreConfig.Adjust()
-	cfg.PDServerCfg.MigrateDeprecatedFlags()
 	if isExist {
 		o.schedule.Store(&cfg.Schedule)
 		o.replication.Store(&cfg.Replication)

tools/pd-ctl/tests/config/config_test.go

@@ -150,7 +150,6 @@ func (suite *configTestSuite) checkConfig(cluster *pdTests.TestCluster) {
 	args = []string{"-u", pdAddr, "config", "set", "trace-region-flow", "false"}
 	_, err = tests.ExecuteCommand(cmd, args...)
 	re.NoError(err)
-	re.False(svr.GetPDServerConfig().TraceRegionFlow)
 
 	origin := svr.GetPDServerConfig().FlowRoundByDigit
 	args = []string{"-u", pdAddr, "config", "set", "flow-round-by-digit", "10"}