diff --git a/internal/distributed/indexnode/client/client.go b/internal/distributed/indexnode/client/client.go
index dd4072b3a1..de6fe23e1a 100644
--- a/internal/distributed/indexnode/client/client.go
+++ b/internal/distributed/indexnode/client/client.go
@@ -33,6 +33,7 @@ import (
 	"github.com/milvus-io/milvus/internal/proto/internalpb"
 )
 
+// Client is the grpc client of IndexNode.
 type Client struct {
 	ctx    context.Context
 	cancel context.CancelFunc
@@ -86,6 +87,7 @@ func (c *Client) resetConnection() {
 	c.grpcClient = nil
 }
 
+// NewClient creates a new IndexNode client.
 func NewClient(ctx context.Context, addr string) (*Client, error) {
 	if addr == "" {
 		return nil, fmt.Errorf("address is empty")
@@ -102,6 +104,7 @@ func NewClient(ctx context.Context, addr string) (*Client, error) {
 	return client, nil
 }
 
+// Init initializes IndexNode's grpc client.
 func (c *Client) Init() error {
 	Params.Init()
 	return nil
@@ -171,10 +174,12 @@ func (c *Client) recall(caller func() (interface{}, error)) (interface{}, error)
 	return ret, err
 }
 
+// Start starts IndexNode's client service. But it does nothing here.
 func (c *Client) Start() error {
 	return nil
 }
 
+// Stop stops IndexNode's grpc client.
 func (c *Client) Stop() error {
 	c.cancel()
 	c.grpcClientMtx.Lock()
@@ -190,6 +195,7 @@ func (c *Client) Register() error {
 	return nil
 }
 
+// GetComponentStates gets the component states of IndexNode.
 func (c *Client) GetComponentStates(ctx context.Context) (*internalpb.ComponentStates, error) {
 	ret, err := c.recall(func() (interface{}, error) {
 		client, err := c.getGrpcClient()
@@ -205,6 +211,7 @@ func (c *Client) GetComponentStates(ctx context.Context) (*internalpb.ComponentS
 	return ret.(*internalpb.ComponentStates), err
 }
 
+// GetTimeTickChannel gets the time tick channel of IndexNode.
 func (c *Client) GetTimeTickChannel(ctx context.Context) (*milvuspb.StringResponse, error) {
 	ret, err := c.recall(func() (interface{}, error) {
 		client, err := c.getGrpcClient()
@@ -220,6 +227,7 @@ func (c *Client) GetTimeTickChannel(ctx context.Context) (*milvuspb.StringRespon
 	return ret.(*milvuspb.StringResponse), err
 }
 
+// GetStatisticsChannel gets the statistics channel of IndexNode.
 func (c *Client) GetStatisticsChannel(ctx context.Context) (*milvuspb.StringResponse, error) {
 	ret, err := c.recall(func() (interface{}, error) {
 		client, err := c.getGrpcClient()
@@ -235,6 +243,7 @@ func (c *Client) GetStatisticsChannel(ctx context.Context) (*milvuspb.StringResp
 	return ret.(*milvuspb.StringResponse), err
 }
 
+// CreateIndex sends the build index request to IndexNode.
 func (c *Client) CreateIndex(ctx context.Context, req *indexpb.CreateIndexRequest) (*commonpb.Status, error) {
 	ret, err := c.recall(func() (interface{}, error) {
 		client, err := c.getGrpcClient()
@@ -250,6 +259,7 @@ func (c *Client) CreateIndex(ctx context.Context, req *indexpb.CreateIndexReques
 	return ret.(*commonpb.Status), err
 }
 
+// GetMetrics gets the metrics info of IndexNode.
 func (c *Client) GetMetrics(ctx context.Context, req *milvuspb.GetMetricsRequest) (*milvuspb.GetMetricsResponse, error) {
 	ret, err := c.recall(func() (interface{}, error) {
 		client, err := c.getGrpcClient()