diff --git a/chaos/cases/source.go b/chaos/cases/source.go
index 545be2bb01..46e2f11780 100644
--- a/chaos/cases/source.go
+++ b/chaos/cases/source.go
@@ -45,16 +45,16 @@ func createSources(ctx context.Context, cli pb.MasterClient, cfg *config) error
 		return err
 	}
 
-	cfg1 := config2.NewSourceConfig()
-	cfg2 := config2.NewSourceConfig()
-	cfg3 := config2.NewSourceConfig()
-	if err = cfg1.ParseYaml(string(s1Content)); err != nil {
+	cfg1, err := config2.ParseYaml(string(s1Content))
+	if err != nil {
 		return err
 	}
-	if err = cfg2.ParseYaml(string(s2Content)); err != nil {
+	cfg2, err := config2.ParseYaml(string(s2Content))
+	if err != nil {
 		return err
 	}
-	if err = cfg3.ParseYaml(string(s3Content)); err != nil {
+	cfg3, err := config2.ParseYaml(string(s3Content))
+	if err != nil {
 		return err
 	}
 
diff --git a/dm/config/source_config.go b/dm/config/source_config.go
index f603fba8bb..f6e7027b25 100644
--- a/dm/config/source_config.go
+++ b/dm/config/source_config.go
@@ -82,6 +82,13 @@ type SourceConfig struct {
 
 // NewSourceConfig creates a new base config for upstream MySQL/MariaDB source.
 func NewSourceConfig() *SourceConfig {
+	c := newSourceConfig()
+	c.adjust()
+	return c
+}
+
+// NewSourceConfig creates a new base config without adjust
+func newSourceConfig() *SourceConfig {
 	c := &SourceConfig{
 		Purge: PurgeConfig{
 			Interval:    60 * 60,
@@ -94,7 +101,6 @@ func NewSourceConfig() *SourceConfig {
 			BackoffMax:      Duration{DefaultBackoffMax},
 		},
 	}
-	c.adjust()
 	return c
 }
 
@@ -140,12 +146,13 @@ func (c *SourceConfig) Parse(content string) error {
 }
 
 // ParseYaml parses flag definitions from the argument list, content should be yaml format.
-func (c *SourceConfig) ParseYaml(content string) error {
-	if err := yaml.Unmarshal([]byte(content), c); err != nil {
-		return terror.ErrConfigYamlTransform.Delegate(err, "decode source config")
+func ParseYaml(content string) (*SourceConfig, error) {
+	c := newSourceConfig()
+	if err := yaml.UnmarshalStrict([]byte(content), c); err != nil {
+		return nil, terror.ErrConfigYamlTransform.Delegate(err, "decode source config")
 	}
 	c.adjust()
-	return nil
+	return c, nil
 }
 
 // EncodeToml encodes config.
@@ -311,16 +318,20 @@ func (c *SourceConfig) AdjustServerID(ctx context.Context, db *sql.DB) error {
 }
 
 // LoadFromFile loads config from file.
-func (c *SourceConfig) LoadFromFile(path string) error {
+func LoadFromFile(path string) (*SourceConfig, error) {
+	c := newSourceConfig()
 	content, err := ioutil.ReadFile(path)
 	if err != nil {
-		return terror.ErrConfigReadCfgFromFile.Delegate(err, path)
+		return nil, terror.ErrConfigReadCfgFromFile.Delegate(err, path)
 	}
 	if err := yaml.UnmarshalStrict(content, c); err != nil {
-		return terror.ErrConfigYamlTransform.Delegate(err, "decode source config")
+		return nil, terror.ErrConfigYamlTransform.Delegate(err, "decode source config")
 	}
 	c.adjust()
-	return c.Verify()
+	if err = c.Verify(); err != nil {
+		return nil, err
+	}
+	return c, nil
 }
 
 func (c *SourceConfig) check(metaData *toml.MetaData, err error) error {
diff --git a/dm/config/source_config_test.go b/dm/config/source_config_test.go
index d33580133d..a59523a931 100644
--- a/dm/config/source_config_test.go
+++ b/dm/config/source_config_test.go
@@ -32,9 +32,8 @@ import (
 const sourceSampleFile = "../worker/source.yaml"
 
 func (t *testConfig) TestConfig(c *C) {
-	cfg := NewSourceConfig()
-
-	c.Assert(cfg.LoadFromFile(sourceSampleFile), IsNil)
+	cfg, err := LoadFromFile(sourceSampleFile)
+	c.Assert(err, IsNil)
 	cfg.RelayDir = "./xx"
 	c.Assert(cfg.RelayDir, Equals, "./xx")
 	c.Assert(cfg.ServerID, Equals, uint32(101))
@@ -63,8 +62,8 @@ func (t *testConfig) TestConfig(c *C) {
 	// test update config file and reload
 	c.Assert(cfg.Parse(tomlStr), IsNil)
 	c.Assert(cfg.ServerID, Equals, uint32(100))
-	var cfg1 SourceConfig
-	c.Assert(cfg1.ParseYaml(yamlStr), IsNil)
+	cfg1, err := ParseYaml(yamlStr)
+	c.Assert(err, IsNil)
 	c.Assert(cfg1.ServerID, Equals, uint32(100))
 	cfg.Filters = []*bf.BinlogEventRule{}
 	cfg.Tracer = map[string]interface{}{}
@@ -73,8 +72,8 @@ func (t *testConfig) TestConfig(c *C) {
 	c.Assert(cfg2.Parse(originCfgStr), IsNil)
 	c.Assert(cfg2.ServerID, Equals, uint32(101))
 
-	var cfg3 SourceConfig
-	c.Assert(cfg3.ParseYaml(originCfgYamlStr), IsNil)
+	cfg3, err := ParseYaml(originCfgYamlStr)
+	c.Assert(err, IsNil)
 	c.Assert(cfg3.ServerID, Equals, uint32(101))
 
 	// test decrypt password
@@ -111,8 +110,8 @@ func (t *testConfig) TestConfig(c *C) {
 	c.Assert(clone4yaml, Matches, "(.|\n)*backoff-rollback: 5m(.|\n)*")
 	c.Assert(clone4yaml, Matches, "(.|\n)*backoff-max: 5m(.|\n)*")
 
-	var clone6 SourceConfig
-	c.Assert(clone6.ParseYaml(clone4yaml), IsNil)
+	clone6, err := ParseYaml(clone4yaml)
+	c.Assert(err, IsNil)
 	c.Assert(clone6, DeepEquals, *clone4)
 
 	// test invalid config
@@ -124,15 +123,15 @@ aaa: xxx
 `)
 	err = ioutil.WriteFile(configFile, configContent, 0o644)
 	c.Assert(err, IsNil)
-	err = cfg.LoadFromFile(configFile)
+	_, err = LoadFromFile(configFile)
 	c.Assert(err, NotNil)
 	c.Assert(err, ErrorMatches, "(.|\n)*field aaa not found in type config.SourceConfig(.|\n)*")
 }
 
 func (t *testConfig) TestConfigVerify(c *C) {
 	newConfig := func() *SourceConfig {
-		cfg := NewSourceConfig()
-		c.Assert(cfg.LoadFromFile(sourceSampleFile), IsNil)
+		cfg, err := LoadFromFile(sourceSampleFile)
+		c.Assert(err, IsNil)
 		cfg.RelayDir = "./xx"
 		return cfg
 	}
@@ -255,12 +254,12 @@ func subtestFlavor(c *C, cfg *SourceConfig, sqlInfo, expectedFlavor, expectedErr
 }
 
 func (t *testConfig) TestAdjustFlavor(c *C) {
-	cfg := NewSourceConfig()
-	c.Assert(cfg.LoadFromFile(sourceSampleFile), IsNil)
+	cfg, err := LoadFromFile(sourceSampleFile)
+	c.Assert(err, IsNil)
 	cfg.RelayDir = "./xx"
 
 	cfg.Flavor = "mariadb"
-	err := cfg.AdjustFlavor(context.Background(), nil)
+	err = cfg.AdjustFlavor(context.Background(), nil)
 	c.Assert(err, IsNil)
 	c.Assert(cfg.Flavor, Equals, mysql.MariaDBFlavor)
 	cfg.Flavor = "MongoDB"
@@ -278,8 +277,8 @@ func (t *testConfig) TestAdjustServerID(c *C) {
 	}()
 	getAllServerIDFunc = getMockServerIDs
 
-	cfg := NewSourceConfig()
-	c.Assert(cfg.LoadFromFile(sourceSampleFile), IsNil)
+	cfg, err := LoadFromFile(sourceSampleFile)
+	c.Assert(err, IsNil)
 	cfg.RelayDir = "./xx"
 
 	c.Assert(cfg.AdjustServerID(context.Background(), nil), IsNil)
diff --git a/dm/master/bootstrap_test.go b/dm/master/bootstrap_test.go
index 66bf4b0b03..258d9fe3f7 100644
--- a/dm/master/bootstrap_test.go
+++ b/dm/master/bootstrap_test.go
@@ -68,13 +68,12 @@ func (t *testMaster) TestCollectSourceConfigFilesV1Import(c *C) {
 	}
 	password := os.Getenv("MYSQL_PSWD")
 
-	// load a valid source file.
-	cfg1 := config.NewSourceConfig()
+	cfg1, err := config.LoadFromFile("./source.yaml")
+	c.Assert(err, IsNil)
 	// fix empty map after marshal/unmarshal becomes nil
 	cfg1.From.Session = map[string]string{}
 	cfg1.Tracer = map[string]interface{}{}
 	cfg1.Filters = []*filter.BinlogEventRule{}
-	c.Assert(cfg1.LoadFromFile("./source.yaml"), IsNil)
 	cfg1.From.Host = host
 	cfg1.From.Port = port
 	cfg1.From.User = user
@@ -122,8 +121,8 @@ func (t *testMaster) TestWaitWorkersReadyV1Import(c *C) {
 	s.cfg.V1SourcesPath = c.MkDir()
 	c.Assert(s.scheduler.Start(ctx, etcdTestCli), IsNil)
 
-	cfg1 := config.NewSourceConfig()
-	c.Assert(cfg1.LoadFromFile("./source.yaml"), IsNil)
+	cfg1, err := config.LoadFromFile("./source.yaml")
+	c.Assert(err, IsNil)
 	cfg2 := cfg1.Clone()
 	cfg2.SourceID = "mysql-replica-02"
 	cfgs := map[string]config.SourceConfig{
@@ -132,7 +131,7 @@ func (t *testMaster) TestWaitWorkersReadyV1Import(c *C) {
 	}
 
 	// no worker registered, timeout.
-	err := s.waitWorkersReadyV1Import(tctx, cfgs)
+	err = s.waitWorkersReadyV1Import(tctx, cfgs)
 	c.Assert(err, ErrorMatches, ".*wait for DM-worker instances timeout.*")
 
 	// register one worker.
diff --git a/dm/master/scheduler/scheduler.go b/dm/master/scheduler/scheduler.go
index eadedf69c5..0caf2acaad 100644
--- a/dm/master/scheduler/scheduler.go
+++ b/dm/master/scheduler/scheduler.go
@@ -76,7 +76,7 @@ type Scheduler struct {
 	// - recover from etcd (calling `recoverSources`).
 	// delete:
 	// - remove source by user request (calling `RemoveSourceCfg`).
-	sourceCfgs map[string]config.SourceConfig
+	sourceCfgs map[string]*config.SourceConfig
 
 	// all subtask configs, task name -> source ID -> subtask config.
 	// add:
@@ -151,7 +151,7 @@ type Scheduler struct {
 func NewScheduler(pLogger *log.Logger, securityCfg config.Security) *Scheduler {
 	return &Scheduler{
 		logger:              pLogger.WithFields(zap.String("component", "scheduler")),
-		sourceCfgs:          make(map[string]config.SourceConfig),
+		sourceCfgs:          make(map[string]*config.SourceConfig),
 		subTaskCfgs:         make(map[string]map[string]config.SubTaskConfig),
 		workers:             make(map[string]*Worker),
 		bounds:              make(map[string]*Worker),
@@ -255,7 +255,7 @@ func (s *Scheduler) CloseAllWorkers() {
 
 // AddSourceCfg adds the upstream source config to the cluster.
 // NOTE: please verify the config before call this.
-func (s *Scheduler) AddSourceCfg(cfg config.SourceConfig) error {
+func (s *Scheduler) AddSourceCfg(cfg *config.SourceConfig) error {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 
@@ -380,7 +380,7 @@ func (s *Scheduler) GetSourceCfgByID(source string) *config.SourceConfig {
 	if !ok {
 		return nil
 	}
-	clone := cfg
+	clone := *cfg
 	return &clone
 }
 
@@ -1745,7 +1745,7 @@ func (s *Scheduler) updateStatusForUnbound(source string) {
 
 // reset resets the internal status.
 func (s *Scheduler) reset() {
-	s.sourceCfgs = make(map[string]config.SourceConfig)
+	s.sourceCfgs = make(map[string]*config.SourceConfig)
 	s.subTaskCfgs = make(map[string]map[string]config.SubTaskConfig)
 	s.workers = make(map[string]*Worker)
 	s.bounds = make(map[string]*Worker)
diff --git a/dm/master/scheduler/scheduler_test.go b/dm/master/scheduler/scheduler_test.go
index 75581797d4..0db2e17ddd 100644
--- a/dm/master/scheduler/scheduler_test.go
+++ b/dm/master/scheduler/scheduler_test.go
@@ -100,7 +100,6 @@ func (t *testScheduler) testSchedulerProgress(c *C, restart int) {
 		taskName2    = "task-2"
 		workerInfo1  = ha.NewWorkerInfo(workerName1, workerAddr1)
 		workerInfo2  = ha.NewWorkerInfo(workerName2, workerAddr2)
-		sourceCfg1   config.SourceConfig
 		subtaskCfg1  config.SubTaskConfig
 		keepAliveTTL = int64(5) // NOTE: this should be >= minLeaseTTL, in second.
 
@@ -116,7 +115,8 @@ func (t *testScheduler) testSchedulerProgress(c *C, restart int) {
 			}
 		}
 	)
-	c.Assert(sourceCfg1.LoadFromFile(sourceSampleFile), IsNil)
+	sourceCfg1, err := config.LoadFromFile(sourceSampleFile)
+	c.Assert(err, IsNil)
 	sourceCfg1.SourceID = sourceID1
 	sourceCfg1.EnableRelay = true
 	sourceCfg2 := sourceCfg1
@@ -550,7 +550,7 @@ func (t *testScheduler) sourceCfgNotExist(c *C, s *Scheduler, source string) {
 	c.Assert(scm, HasLen, 0)
 }
 
-func (t *testScheduler) sourceCfgExist(c *C, s *Scheduler, expectCfg config.SourceConfig) {
+func (t *testScheduler) sourceCfgExist(c *C, s *Scheduler, expectCfg *config.SourceConfig) {
 	cfgP := s.GetSourceCfgByID(expectCfg.SourceID)
 	c.Assert(cfgP, DeepEquals, &expectCfg)
 	scm, _, err := ha.GetSourceCfg(etcdTestCli, expectCfg.SourceID, 0)
@@ -708,11 +708,11 @@ func (t *testScheduler) TestRestartScheduler(c *C) {
 		workerAddr1  = "127.0.0.1:8262"
 		workerInfo1  = ha.NewWorkerInfo(workerName1, workerAddr1)
 		sourceBound1 = ha.NewSourceBound(sourceID1, workerName1)
-		sourceCfg1   config.SourceConfig
 		wg           sync.WaitGroup
 		keepAliveTTL = int64(2) // NOTE: this should be >= minLeaseTTL, in second.
 	)
-	c.Assert(sourceCfg1.LoadFromFile(sourceSampleFile), IsNil)
+	sourceCfg1, err := config.LoadFromFile(sourceSampleFile)
+	c.Assert(err, IsNil)
 	sourceCfg1.SourceID = sourceID1
 
 	s := NewScheduler(&logger, config.Security{})
@@ -822,10 +822,10 @@ func (t *testScheduler) TestWatchWorkerEventEtcdCompact(c *C) {
 		workerAddr2  = "127.0.0.1:18262"
 		workerAddr3  = "127.0.0.1:18362"
 		workerAddr4  = "127.0.0.1:18462"
-		sourceCfg1   config.SourceConfig
 		keepAliveTTL = int64(2) // NOTE: this should be >= minLeaseTTL, in second.
 	)
-	c.Assert(sourceCfg1.LoadFromFile(sourceSampleFile), IsNil)
+	sourceCfg1, err := config.LoadFromFile(sourceSampleFile)
+	c.Assert(err, IsNil)
 	sourceCfg1.SourceID = sourceID1
 	sourceCfg2 := sourceCfg1
 	sourceCfg2.SourceID = sourceID2
@@ -884,7 +884,7 @@ func (t *testScheduler) TestWatchWorkerEventEtcdCompact(c *C) {
 
 	// step 4: trigger etcd compaction and check whether we can receive it through watcher
 	var startRev int64 = 1
-	_, err := etcdTestCli.Compact(ctx, rev)
+	_, err = etcdTestCli.Compact(ctx, rev)
 	c.Assert(err, IsNil)
 	workerEvCh := make(chan ha.WorkerEvent, 10)
 	workerErrCh := make(chan error, 10)
@@ -962,10 +962,10 @@ func (t *testScheduler) TestLastBound(c *C) {
 		workerName2 = "dm-worker-2"
 		workerName3 = "dm-worker-3"
 		workerName4 = "dm-worker-4"
-		sourceCfg1  config.SourceConfig
 	)
 
-	c.Assert(sourceCfg1.LoadFromFile(sourceSampleFile), IsNil)
+	sourceCfg1, err := config.LoadFromFile(sourceSampleFile)
+	c.Assert(err, IsNil)
 	sourceCfg1.SourceID = sourceID1
 	sourceCfg2 := sourceCfg1
 	sourceCfg2.SourceID = sourceID2
@@ -1052,8 +1052,8 @@ func (t *testScheduler) TestTransferSource(c *C) {
 	s.workers[workerName2] = worker2
 	s.workers[workerName3] = worker3
 	s.workers[workerName4] = worker4
-	s.sourceCfgs[sourceID1] = config.SourceConfig{}
-	s.sourceCfgs[sourceID2] = config.SourceConfig{}
+	s.sourceCfgs[sourceID1] = &config.SourceConfig{}
+	s.sourceCfgs[sourceID2] = &config.SourceConfig{}
 
 	worker1.ToFree()
 	c.Assert(s.boundSourceToWorker(sourceID1, worker1), IsNil)
@@ -1075,7 +1075,7 @@ func (t *testScheduler) TestTransferSource(c *C) {
 	c.Assert(worker1.Stage(), Equals, WorkerFree)
 
 	// test valid transfer: source -> worker = unbound -> free
-	s.sourceCfgs[sourceID3] = config.SourceConfig{}
+	s.sourceCfgs[sourceID3] = &config.SourceConfig{}
 	s.unbounds[sourceID3] = struct{}{}
 	c.Assert(s.TransferSource(sourceID3, workerName3), IsNil)
 	c.Assert(s.bounds[sourceID3], DeepEquals, worker3)
@@ -1095,7 +1095,7 @@ func (t *testScheduler) TestTransferSource(c *C) {
 	c.Assert(s.bounds[sourceID1], DeepEquals, worker4)
 
 	// test invalid transfer: source -> worker = unbound -> bound
-	s.sourceCfgs[sourceID4] = config.SourceConfig{}
+	s.sourceCfgs[sourceID4] = &config.SourceConfig{}
 	s.unbounds[sourceID4] = struct{}{}
 	c.Assert(s.TransferSource(sourceID4, workerName3), NotNil)
 	c.Assert(s.bounds[sourceID3], DeepEquals, worker3)
@@ -1147,8 +1147,8 @@ func (t *testScheduler) TestStartStopSource(c *C) {
 	s.workers[workerName2] = worker2
 	s.workers[workerName3] = worker3
 	s.workers[workerName4] = worker4
-	s.sourceCfgs[sourceID1] = config.SourceConfig{}
-	s.sourceCfgs[sourceID2] = config.SourceConfig{}
+	s.sourceCfgs[sourceID1] = &config.SourceConfig{}
+	s.sourceCfgs[sourceID2] = &config.SourceConfig{}
 
 	worker1.ToFree()
 	c.Assert(s.boundSourceToWorker(sourceID1, worker1), IsNil)
diff --git a/dm/master/server.go b/dm/master/server.go
index d4c5e7f743..08c4d673a3 100644
--- a/dm/master/server.go
+++ b/dm/master/server.go
@@ -1079,10 +1079,11 @@ func (s *Server) CheckTask(ctx context.Context, req *pb.CheckTaskRequest) (*pb.C
 func parseAndAdjustSourceConfig(ctx context.Context, contents []string) ([]*config.SourceConfig, error) {
 	cfgs := make([]*config.SourceConfig, len(contents))
 	for i, content := range contents {
-		cfg := config.NewSourceConfig()
-		if err := cfg.ParseYaml(content); err != nil {
+		cfg, err := config.ParseYaml(content)
+		if err != nil {
 			return cfgs, err
 		}
+		cfg.From.Adjust()
 
 		dbConfig := cfg.GenerateDBConfig()
 
@@ -1112,8 +1113,8 @@ func parseAndAdjustSourceConfig(ctx context.Context, contents []string) ([]*conf
 func parseSourceConfig(contents []string) ([]*config.SourceConfig, error) {
 	cfgs := make([]*config.SourceConfig, len(contents))
 	for i, content := range contents {
-		cfg := config.NewSourceConfig()
-		if err := cfg.ParseYaml(content); err != nil {
+		cfg, err := config.ParseYaml(content)
+		if err != nil {
 			return cfgs, err
 		}
 		cfgs[i] = cfg
diff --git a/dm/master/server_test.go b/dm/master/server_test.go
index c81c0c3e0f..85021c28ee 100644
--- a/dm/master/server_test.go
+++ b/dm/master/server_test.go
@@ -1468,8 +1468,8 @@ func (t *testMaster) TestOperateSource(c *check.C) {
 	s1.leader.Store(oneselfLeader)
 	c.Assert(s1.Start(ctx), check.IsNil)
 	defer s1.Close()
-	mysqlCfg := config.NewSourceConfig()
-	c.Assert(mysqlCfg.LoadFromFile("./source.yaml"), check.IsNil)
+	mysqlCfg, err := config.LoadFromFile("./source.yaml")
+	c.Assert(err, check.IsNil)
 	mysqlCfg.From.Password = os.Getenv("MYSQL_PSWD")
 	task, err := mysqlCfg.Yaml()
 	c.Assert(err, check.IsNil)
diff --git a/dm/worker/relay_test.go b/dm/worker/relay_test.go
index 4b31463567..4bbec4a6b9 100644
--- a/dm/worker/relay_test.go
+++ b/dm/worker/relay_test.go
@@ -145,7 +145,7 @@ func (t *testRelay) TestRelay(c *C) {
 	cfg.RelayDir = dir
 	cfg.MetaDir = dir
 
-	relayHolder := NewRealRelayHolder(&cfg)
+	relayHolder := NewRealRelayHolder(cfg)
 	c.Assert(relayHolder, NotNil)
 
 	holder, ok := relayHolder.(*realRelayHolder)
diff --git a/dm/worker/server_test.go b/dm/worker/server_test.go
index 1d078a3b88..2b44f379f2 100644
--- a/dm/worker/server_test.go
+++ b/dm/worker/server_test.go
@@ -386,7 +386,7 @@ func (t *testServer) TestWatchSourceBoundEtcdCompact(c *C) {
 	rev, err := ha.DeleteSourceBound(etcdCli, cfg.Name)
 	c.Assert(err, IsNil)
 	// step 2: start source at this worker
-	w, err := s.getOrStartWorker(&sourceCfg, true)
+	w, err := s.getOrStartWorker(sourceCfg, true)
 	c.Assert(err, IsNil)
 	c.Assert(w.EnableHandleSubtasks(), IsNil)
 	// step 3: trigger etcd compaction and check whether we can receive it through watcher
@@ -633,9 +633,8 @@ func checkRelayStatus(cli pb.WorkerClient, expect pb.Stage) bool {
 	return status.SourceStatus.RelayStatus.Stage == expect
 }
 
-func loadSourceConfigWithoutPassword(c *C) config.SourceConfig {
-	var sourceCfg config.SourceConfig
-	err := sourceCfg.LoadFromFile(sourceSampleFile)
+func loadSourceConfigWithoutPassword(c *C) *config.SourceConfig {
+	sourceCfg, err := config.LoadFromFile(sourceSampleFile)
 	c.Assert(err, IsNil)
 	sourceCfg.From.Password = "" // no password set
 	return sourceCfg
diff --git a/pkg/ha/bound_test.go b/pkg/ha/bound_test.go
index fa95f6c0b7..9dd8f714d2 100644
--- a/pkg/ha/bound_test.go
+++ b/pkg/ha/bound_test.go
@@ -128,10 +128,10 @@ func (t *testForEtcd) TestGetSourceBoundConfigEtcd(c *C) {
 		worker   = "dm-worker-1"
 		source   = "mysql-replica-1"
 		bound    = NewSourceBound(source, worker)
-		cfg      config.SourceConfig
 		emptyCfg config.SourceConfig
 	)
-	c.Assert(cfg.LoadFromFile(sourceSampleFile), IsNil)
+	cfg, err := config.LoadFromFile(sourceSampleFile)
+	c.Assert(err, IsNil)
 	cfg.SourceID = source
 	// no source bound and config
 	bound1, cfg1, rev1, err := GetSourceBoundConfig(etcdTestCli, worker)
diff --git a/pkg/ha/ops_test.go b/pkg/ha/ops_test.go
index 3ad51caaff..80f129ae54 100644
--- a/pkg/ha/ops_test.go
+++ b/pkg/ha/ops_test.go
@@ -34,11 +34,11 @@ func (t *testForEtcd) TestOpsEtcd(c *C) {
 		bound         = NewSourceBound(source, worker)
 
 		emptyStage  Stage
-		sourceCfg   config.SourceConfig
 		subtaskCfg1 config.SubTaskConfig
 	)
 
-	c.Assert(sourceCfg.LoadFromFile(sourceSampleFile), IsNil)
+	sourceCfg, err := config.LoadFromFile(sourceSampleFile)
+	c.Assert(err, IsNil)
 	sourceCfg.SourceID = source
 	c.Assert(subtaskCfg1.DecodeFile(subTaskSampleFile, true), IsNil)
 	subtaskCfg1.SourceID = source
diff --git a/pkg/ha/relay_test.go b/pkg/ha/relay_test.go
index 08d62aca46..05d7f9bb45 100644
--- a/pkg/ha/relay_test.go
+++ b/pkg/ha/relay_test.go
@@ -25,9 +25,9 @@ func (t *testForEtcd) TestGetRelayConfigEtcd(c *C) {
 	var (
 		worker = "dm-worker-1"
 		source = "mysql-replica-1"
-		cfg    config.SourceConfig
 	)
-	c.Assert(cfg.LoadFromFile(sourceSampleFile), IsNil)
+	cfg, err := config.LoadFromFile(sourceSampleFile)
+	c.Assert(err, IsNil)
 	cfg.SourceID = source
 	// no relay source and config
 	cfg1, rev1, err := GetRelayConfig(etcdTestCli, worker)
diff --git a/pkg/ha/source.go b/pkg/ha/source.go
index de0d7c661f..bb9cc49684 100644
--- a/pkg/ha/source.go
+++ b/pkg/ha/source.go
@@ -27,7 +27,7 @@ import (
 
 // PutSourceCfg puts the config of the upstream source into etcd.
 // k/v: sourceID -> source config.
-func PutSourceCfg(cli *clientv3.Client, cfg config.SourceConfig) (int64, error) {
+func PutSourceCfg(cli *clientv3.Client, cfg *config.SourceConfig) (int64, error) {
 	value, err := cfg.Toml()
 	if err != nil {
 		return 0, err
@@ -42,12 +42,12 @@ func PutSourceCfg(cli *clientv3.Client, cfg config.SourceConfig) (int64, error)
 // if the source config for the sourceID not exist, return with `err == nil`.
 // if the source name is "", it will return all source configs as a map{sourceID: config}.
 // if the source name is given, it will return a map{sourceID: config} whose length is 1.
-func GetSourceCfg(cli *clientv3.Client, source string, rev int64) (map[string]config.SourceConfig, int64, error) {
+func GetSourceCfg(cli *clientv3.Client, source string, rev int64) (map[string]*config.SourceConfig, int64, error) {
 	ctx, cancel := context.WithTimeout(cli.Ctx(), etcdutil.DefaultRequestTimeout)
 	defer cancel()
 
 	var (
-		scm  = make(map[string]config.SourceConfig)
+		scm  = make(map[string]*config.SourceConfig)
 		resp *clientv3.GetResponse
 		err  error
 	)
@@ -77,8 +77,8 @@ func deleteSourceCfgOp(source string) clientv3.Op {
 	return clientv3.OpDelete(common.UpstreamConfigKeyAdapter.Encode(source))
 }
 
-func sourceCfgFromResp(source string, resp *clientv3.GetResponse) (map[string]config.SourceConfig, error) {
-	scm := make(map[string]config.SourceConfig)
+func sourceCfgFromResp(source string, resp *clientv3.GetResponse) (map[string]*config.SourceConfig, error) {
+	scm := make(map[string]*config.SourceConfig)
 	if resp.Count == 0 {
 		return scm, nil
 	} else if source != "" && resp.Count > 1 {
@@ -92,7 +92,7 @@ func sourceCfgFromResp(source string, resp *clientv3.GetResponse) (map[string]co
 		if err != nil {
 			return scm, terror.ErrConfigEtcdParse.Delegate(err, kv.Key)
 		}
-		scm[cfg.SourceID] = cfg
+		scm[cfg.SourceID] = &cfg
 	}
 	return scm, nil
 }
diff --git a/pkg/ha/source_test.go b/pkg/ha/source_test.go
index af7568c1e3..44d4da4704 100644
--- a/pkg/ha/source_test.go
+++ b/pkg/ha/source_test.go
@@ -52,9 +52,8 @@ var _ = Suite(&testForEtcd{})
 func (t *testForEtcd) TestSourceEtcd(c *C) {
 	defer clearTestInfoOperation(c)
 
-	var cfg config.SourceConfig
-
-	c.Assert(cfg.LoadFromFile(sourceSampleFile), IsNil)
+	cfg, err := config.LoadFromFile(sourceSampleFile)
+	c.Assert(err, IsNil)
 	source := cfg.SourceID
 	cfgExtra := cfg
 	cfgExtra.SourceID = "mysql-replica-2"