diff --git a/server/controller/prometheus/encoder/label.go b/server/controller/prometheus/encoder/label.go
index cc8cf8834e3..636bfaf9950 100644
--- a/server/controller/prometheus/encoder/label.go
+++ b/server/controller/prometheus/encoder/label.go
@@ -52,7 +52,7 @@ func newLabel(org *common.ORG, ln *labelName, lv *labelValue) *label {
 
 func (l *label) store(item *metadbmodel.PrometheusLabel) {
 	nameID, ok1 := l.labelName.getID(item.Name)
-	valueID, ok2 := l.labelValue.getID(item.Value)
+	valueID, ok2 := l.labelValue.getIDSafe(item.Value)
 	if !ok1 || !ok2 {
 		return
 	}
@@ -107,7 +107,7 @@ func (l *label) refresh(args ...interface{}) error {
 			return scanErr
 		}
 		nameID, ok1 := l.labelName.getID(name)
-		valueID, ok2 := l.labelValue.getID(value)
+		valueID, ok2 := l.labelValue.getIDSafe(value)
 		if ok1 && ok2 {
 			newMap[cache.IDLabelKey{NameID: nameID, ValueID: valueID}] = id
 		}
@@ -129,15 +129,13 @@ func (l *label) refresh(args ...interface{}) error {
 
 func (l *label) encode(toAdd []*controller.PrometheusLabelRequest) ([]*controller.PrometheusLabel, error) {
 	l.lock.Lock()
-	defer l.lock.Unlock()
-
 	resp := make([]*controller.PrometheusLabel, 0)
 	var dbToAdd []*metadbmodel.PrometheusLabel
 	for _, item := range toAdd {
 		n := item.GetName()
 		v := item.GetValue()
 		nameID, ok1 := l.labelName.getID(n)
-		valueID, ok2 := l.labelValue.getID(v)
+		valueID, ok2 := l.labelValue.getIDSafe(v)
 		if ok1 && ok2 {
 			if id, ok := l.getID(cache.IDLabelKey{NameID: nameID, ValueID: valueID}); ok {
 				resp = append(resp, &controller.PrometheusLabel{
@@ -153,12 +151,19 @@ func (l *label) encode(toAdd []*controller.PrometheusLabelRequest) ([]*controlle
 			Value: v,
 		})
 	}
+	l.lock.Unlock()
+
+	if len(dbToAdd) == 0 {
+		return resp, nil
+	}
 
 	err := addBatch(l.org.DB, dbToAdd, l.resourceType)
 	if err != nil {
 		log.Errorf("add %s error: %s", l.resourceType, err.Error(), l.org.LogPrefix)
 		return nil, err
 	}
+
+	l.lock.Lock()
 	for _, item := range dbToAdd {
 		l.store(item)
 		resp = append(resp, &controller.PrometheusLabel{
@@ -166,7 +171,7 @@ func (l *label) encode(toAdd []*controller.PrometheusLabelRequest) ([]*controlle
 			Value: &item.Value,
 			Id:    proto.Uint32(uint32(item.ID)),
 		})
-
 	}
+	l.lock.Unlock()
 	return resp, nil
 }
diff --git a/server/controller/prometheus/encoder/label_value.go b/server/controller/prometheus/encoder/label_value.go
index fdc757419cf..9cbb72c648b 100644
--- a/server/controller/prometheus/encoder/label_value.go
+++ b/server/controller/prometheus/encoder/label_value.go
@@ -102,8 +102,6 @@ func (lv *labelValue) refresh(args ...interface{}) error {
 
 func (lv *labelValue) encode(strs []string) ([]*controller.PrometheusLabelValue, error) {
 	lv.lock.Lock()
-	defer lv.lock.Unlock()
-
 	resp := make([]*controller.PrometheusLabelValue, 0)
 	dbToAdd := make([]*metadbmodel.PrometheusLabelValue, 0)
 	for i := range strs {
@@ -114,6 +112,8 @@ func (lv *labelValue) encode(strs []string) ([]*controller.PrometheusLabelValue,
 		}
 		dbToAdd = append(dbToAdd, &metadbmodel.PrometheusLabelValue{Value: str})
 	}
+	lv.lock.Unlock()
+
 	if len(dbToAdd) == 0 {
 		return resp, nil
 	}
@@ -123,10 +123,13 @@ func (lv *labelValue) encode(strs []string) ([]*controller.PrometheusLabelValue,
 		log.Errorf("add %s error: %s", lv.resourceType, err.Error(), lv.org.LogPrefix)
 		return nil, err
 	}
+
+	lv.lock.Lock()
 	for i := range dbToAdd {
 		lv.store(dbToAdd[i])
 		resp = append(resp, &controller.PrometheusLabelValue{Value: &dbToAdd[i].Value, Id: proto.Uint32(uint32(dbToAdd[i].ID))})
 	}
+	lv.lock.Unlock()
 	return resp, nil
 }
 
@@ -135,6 +138,13 @@ func (lv *labelValue) getID(str string) (int, bool) {
 	return id, ok
 }
 
+// getIDSafe is a thread-safe variant for callers that do not already hold lv.lock.
+func (lv *labelValue) getIDSafe(str string) (int, bool) {
+	lv.lock.Lock()
+	defer lv.lock.Unlock()
+	return lv.getID(str)
+}
+
 func (lv *labelValue) store(item *metadbmodel.PrometheusLabelValue) {
 	lv.strToID[item.Value] = item.ID
 
diff --git a/server/controller/prometheus/label.go b/server/controller/prometheus/label.go
index 14a9630b7d5..07d1f273f70 100644
--- a/server/controller/prometheus/label.go
+++ b/server/controller/prometheus/label.go
@@ -329,10 +329,10 @@ func (s *LabelSynchronizer) assembleMetricLabel(mls []*trident.MetricLabelReques
 		log.Errorf("metric name id not found, name to request count: %+v", nonMetricNameToCount, s.org.LogPrefix)
 	}
 	if nonLabelNames.Cardinality() > 0 {
-		log.Errorf("label name id not found, names: %v", nonLabelNames.ToSlice(), s.org.LogPrefix)
+		log.Errorf("label name id not found, %s", logNotFoundDetail(nonLabelNames.ToSlice()), s.org.LogPrefix)
 	}
 	if nonLabelValues.Cardinality() > 0 {
-		log.Errorf("label value id not found, values: %v", nonLabelValues.ToSlice(), s.org.LogPrefix)
+		log.Errorf("label value id not found, %s", logNotFoundDetail(nonLabelValues.ToSlice()), s.org.LogPrefix)
 	}
 	return respMLs, nil
 }