diff --git a/pkg/mcs/metastorage/server/grpc_service.go b/pkg/mcs/metastorage/server/grpc_service.go
index 4f43114ea29..77003c47b17 100644
--- a/pkg/mcs/metastorage/server/grpc_service.go
+++ b/pkg/mcs/metastorage/server/grpc_service.go
@@ -71,9 +71,9 @@ func (s *Service) RegisterGRPCService(g *grpc.Server) {
 }
 
 // RegisterRESTHandler registers the service to REST server.
-func (s *Service) RegisterRESTHandler(userDefineHandlers map[string]http.Handler) error {
-	handler, group := SetUpRestHandler(s)
-	return apiutil.RegisterUserDefinedHandlers(userDefineHandlers, &group, handler)
+func (s *Service) RegisterRESTHandler(_ map[string]http.Handler) error {
+	// restful API is not implemented yet.
+	return nil
 }
 
 func (s *Service) checkServing() error {
diff --git a/tools/pd-api-bench/README.md b/tools/pd-api-bench/README.md
index 019dbd5e6a3..76d568b3787 100644
--- a/tools/pd-api-bench/README.md
+++ b/tools/pd-api-bench/README.md
@@ -66,7 +66,7 @@ The api bench cases we support are as follows:
 You can run shell as follows.
 
 ```shell
-go run main.go -http-cases GetRegionStatus-1+1,GetMinResolvedTS-1+1 -client 1 -debug true
+go run main.go --http-cases GetRegionStatus-1+1,GetMinResolvedTS-1+1 --client 1 --debug true
 ```
 
 ### TLS
@@ -76,7 +76,7 @@ You can use the following command to generate a certificate for testing TLS:
 ```shell
 mkdir cert
 ./cert_opt.sh generate cert
-go run main.go -http-cases GetRegionStatus-1+1,GetMinResolvedTS-1+1 -client 1 -debug true -cacert ./cert/ca.pem -cert ./cert/pd-server.pem  -key ./cert/pd-server-key.pem
+go run main.go --http-cases GetRegionStatus-1+1,GetMinResolvedTS-1+1 --client 1 --debug true --cacert ./cert/ca.pem --cert ./cert/pd-server.pem  --key ./cert/pd-server-key.pem
 ./cert_opt.sh cleanup cert
 rm -rf cert
 ```
diff --git a/tools/pd-simulator/simulator/drive.go b/tools/pd-simulator/simulator/drive.go
index 947d0664755..22d4175ecc6 100644
--- a/tools/pd-simulator/simulator/drive.go
+++ b/tools/pd-simulator/simulator/drive.go
@@ -266,7 +266,6 @@ func (d *Driver) RegionsHeartbeat(ctx context.Context) {
 						healthyNodes[n.Store.GetId()] = true
 					}
 				}
-				report := 0
 				for _, region := range regions {
 					hibernatePercent := d.simConfig.HibernatePercent
 					// using rand(0,100) to meet hibernatePercent
@@ -280,7 +279,6 @@ func (d *Driver) RegionsHeartbeat(ctx context.Context) {
 							continue
 						}
 						nodesChannel[storeID] <- region.Clone()
-						report++
 					}
 				}