diff --git a/core/load/sheddergroup.go b/core/load/sheddergroup.go
index 6937ea55..12fcf6d6 100644
--- a/core/load/sheddergroup.go
+++ b/core/load/sheddergroup.go
@@ -6,11 +6,13 @@ import (
 	"github.com/tal-tech/go-zero/core/syncx"
 )
 
+// A ShedderGroup is a manager to manage key based shedders.
 type ShedderGroup struct {
 	options []ShedderOption
 	manager *syncx.ResourceManager
 }
 
+// NewShedderGroup returns a ShedderGroup.
 func NewShedderGroup(opts ...ShedderOption) *ShedderGroup {
 	return &ShedderGroup{
 		options: opts,
@@ -18,6 +20,7 @@ func NewShedderGroup(opts ...ShedderOption) *ShedderGroup {
 	}
 }
 
+// GetShedder gets the Shedder for the given key.
 func (g *ShedderGroup) GetShedder(key string) Shedder {
 	shedder, _ := g.manager.GetResource(key, func() (closer io.Closer, e error) {
 		return nopCloser{
diff --git a/core/load/sheddingstat.go b/core/load/sheddingstat.go
index 7755d693..2a12d969 100644
--- a/core/load/sheddingstat.go
+++ b/core/load/sheddingstat.go
@@ -9,6 +9,7 @@ import (
 )
 
 type (
+	// A SheddingStat is used to store the statistics for load shedding.
 	SheddingStat struct {
 		name  string
 		total int64
@@ -23,6 +24,7 @@ type (
 	}
 )
 
+// NewSheddingStat returns a SheddingStat.
 func NewSheddingStat(name string) *SheddingStat {
 	st := &SheddingStat{
 		name: name,
@@ -31,14 +33,17 @@ func NewSheddingStat(name string) *SheddingStat {
 	return st
 }
 
+// IncrementTotal increments the total requests.
 func (s *SheddingStat) IncrementTotal() {
 	atomic.AddInt64(&s.total, 1)
 }
 
+// IncrementPass increments the passed requests.
 func (s *SheddingStat) IncrementPass() {
 	atomic.AddInt64(&s.pass, 1)
 }
 
+// IncrementDrop increments the dropped requests.
 func (s *SheddingStat) IncrementDrop() {
 	atomic.AddInt64(&s.drop, 1)
 }