feat(backend): Add switching logic for Spider Slave nodes. issue: #15620

Author: XH-2019

dbm-services/common/dbha-v2/internal/analysis/switcher/mysql.go

@@ -120,8 +120,12 @@ func (m *Mysql) Switch(ctx context.Context, req *Request) *Response {
 		swInst.SetSwitchLogger(switchLoggers)
 
 		logger.Info("start to switch the single mysql instance: %s", instKey)
-		if swErr := SwitchSingleInstance(swInst); swErr != nil {
-			logger.Warn("failed to switch the single mysql instance: %s, errmsg: %s", instKey, swErr)
+		if switchSuccess, swErr := SwitchSingleInstance(swInst); !switchSuccess {
+			errStr := "nil"
+			if swErr != nil {
+				errStr = swErr.Error()
+			}
+			logger.Warn("failed to switch the single mysql instance: %s, errmsg: %s", instKey, errStr)
 			rsp.MySqlFailureInsts[instKey] = inst
 			continue
 		}

dbm-services/common/dbha-v2/internal/analysis/switcher/switchable_instance.go

@@ -77,12 +77,12 @@ type SwitchableInstance interface {
 }
 
 // SwitchSingleInstance executes the standardized switching procedure for a single database instance.
-func SwitchSingleInstance(ins SwitchableInstance) (retErr error) {
+func SwitchSingleInstance(ins SwitchableInstance) (switchSuccess bool, retErr error) {
 	ins.ReportLogf(SwitchInfo, "start to switch single instance: %s", ins.GetInstanceInfo())
 
 	// rollback when error occurs
 	defer func() {
-		if retErr == nil {
+		if switchSuccess {
 			ins.ReportLogf(SwitchSuccess, "successfully switch single instance: %s", ins.GetInstanceInfo())
 			return
 		}
@@ -98,14 +98,14 @@ func SwitchSingleInstance(ins SwitchableInstance) (retErr error) {
 	if (ins.GetStatus() != dbm.Running) && (ins.GetStatus() != dbm.Available) {
 		retErr = gerrors.Newf(gerrors.Failure, "pre-status check unpass for wrong status:%s", ins.GetStatus())
 		ins.ReportLogf(SwitchFail, "%s", retErr.Error())
-		return
+		return false, retErr
 	}
 	ins.ReportLogf(SwitchInfo, "pre-status check pass with status:%s", ins.GetStatus())
 
 	if err := ins.SetInstanceUnavailable(); err != nil {
 		retErr = gerrors.Newf(gerrors.Failure, "failed to set instance unavailable: %s", err.Error())
 		ins.ReportLogf(SwitchFail, "%s", retErr.Error())
-		return
+		return false, retErr
 	}
 	ins.ReportLogf(SwitchInfo, "successfully set instance unavailable")
 
@@ -115,36 +115,38 @@ func SwitchSingleInstance(ins SwitchableInstance) (retErr error) {
 		ins.ReportLogf(SwitchInfo, "check result before switch: switch required")
 	case SwitchNotNeeded:
 		ins.ReportLogf(SwitchInfo, "check result before switch: no need to switch")
-		return
+		return true, nil
 	default:
 		errMsg := "check result before switch: check unpass"
 		if checkErr != nil {
 			errMsg += fmt.Sprintf(", errmsg: %s", checkErr.Error())
 		}
+
+		retErr = gerrors.Newf(gerrors.Failure, "%s", errMsg)
 		ins.ReportLogf(SwitchFail, "%s", errMsg)
-		return
+		return false, retErr
 	}
 
 	if err := ins.DoSwitch(); err != nil {
 		retErr = gerrors.Newf(gerrors.Failure, "failed to do switch: %s", err.Error())
 		ins.ReportLogf(SwitchFail, "%s", retErr.Error())
-		return
+		return false, retErr
 	}
 	ins.ReportLogf(SwitchInfo, "successfully do switch")
 
 	if err := ins.UpdateMetaInfo(); err != nil {
 		retErr = gerrors.Newf(gerrors.Failure, "failed to update meta info: %s", err.Error())
 		ins.ReportLogf(SwitchFail, "%s", retErr.Error())
-		return
+		return false, retErr
 	}
 	ins.ReportLogf(SwitchInfo, "successfully update meta info")
 
 	if err := ins.DoFinal(); err != nil {
 		retErr = gerrors.Newf(gerrors.Failure, "failed to do final step: %s", err.Error())
 		ins.ReportLogf(SwitchFail, "%s", retErr.Error())
-		return
+		return false, retErr
 	}
 	ins.ReportLogf(SwitchInfo, "successfully do final step")
 
-	return
+	return true, nil
 }

dbm-services/common/dbha-v2/internal/analysis/switcher/tendbcluster_switch_instance.go

@@ -588,6 +588,21 @@ func (sw *TenDBClusterSpiderSwitchInstance) UnmarshalTdbctlReplInfo(replicationI
 	return replInfo, nil
 }
 
+// CheckBeforeSwitch check slave before switch
+func (sw *TenDBClusterSpiderSwitchInstance) CheckBeforeSwitch() (SwitchCheckCode, error) {
+	switch sw.SpiderRole {
+	case dbm.TenDBClusterSpiderMaster:
+		return SwitchRequired, nil
+	case dbm.TenDBClusterSpiderSlave:
+		sw.ReportLogf(SwitchInfo, "this is a spider slave node, no need to check")
+		return SwitchNotNeeded, nil
+	default:
+		err := gerrors.Newf(gerrors.Failure, "invalid instance role: %s", sw.SpiderRole)
+		sw.ReportLogf(SwitchWarn, "%s", err.Error())
+		return SwitchCheckUnpass, err
+	}
+}
+
 // TdbctlEnablePrimary connect tdbctl and execute TDBCTL ENABLE PRIMARY [FORCE]
 func (sw *TenDBClusterSpiderSwitchInstance) TdbctlEnablePrimary(tdbctlHost string, tdbctlPort int, force bool) error {
 	tdbctlDB, connErr := sw.ConnectTdbctlNode(tdbctlHost, tdbctlPort)