diff --git a/server/grpc_gateway_test.go b/server/grpc_gateway_test.go
new file mode 100644
index 0000000..72b36ee
--- /dev/null
+++ b/server/grpc_gateway_test.go
@@ -0,0 +1,38 @@
+package server
+
+import (
+	"fmt"
+	"testing"
+	"time"
+
+	"github.com/mosuka/blast/log"
+	"github.com/mosuka/blast/util"
+)
+
+func Test_GRPCGateway_Start_Stop(t *testing.T) {
+	httpAddress := fmt.Sprintf(":%d", util.TmpPort())
+	grpcAddress := fmt.Sprintf(":%d", util.TmpPort())
+	certificateFile := ""
+	KeyFile := ""
+	commonName := ""
+	corsAllowedMethods := make([]string, 0)
+	corsAllowedOrigins := make([]string, 0)
+	corsAllowedHeaders := make([]string, 0)
+	logger := log.NewLogger("WARN", "", 500, 3, 30, false)
+
+	grpcGateway, err := NewGRPCGateway(httpAddress, grpcAddress, certificateFile, KeyFile, commonName, corsAllowedMethods, corsAllowedOrigins, corsAllowedHeaders, logger)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	defer func() {
+		if err := grpcGateway.Stop(); err != nil {
+			t.Fatalf("%v", err)
+		}
+	}()
+
+	if err := grpcGateway.Start(); err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	time.Sleep(3 * time.Second)
+}
diff --git a/server/grpc_server_test.go b/server/grpc_server_test.go
new file mode 100644
index 0000000..67596d8
--- /dev/null
+++ b/server/grpc_server_test.go
@@ -0,0 +1,72 @@
+package server
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/mosuka/blast/log"
+	"github.com/mosuka/blast/mapping"
+	"github.com/mosuka/blast/util"
+)
+
+func Test_GRPCServer_Start_Stop(t *testing.T) {
+	curDir, err := os.Getwd()
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	tmpDir := util.TmpDir()
+	defer func() {
+		_ = os.RemoveAll(tmpDir)
+	}()
+
+	logger := log.NewLogger("WARN", "", 500, 3, 30, false)
+
+	// Raft server
+	rafAddress := fmt.Sprintf(":%d", util.TmpPort())
+	dir := util.TmpDir()
+	defer func() {
+		_ = os.RemoveAll(dir)
+	}()
+	indexMapping, err := mapping.NewIndexMappingFromFile(filepath.Join(curDir, "../examples/example_mapping.json"))
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	raftServer, err := NewRaftServer("node1", rafAddress, dir, indexMapping, true, logger)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	defer func() {
+		if err := raftServer.Stop(); err != nil {
+			t.Fatalf("%v", err)
+		}
+	}()
+	if err := raftServer.Start(); err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	// gRPC server
+	grpcAddress := fmt.Sprintf(":%d", util.TmpPort())
+	certificateFile := ""
+	keyFile := ""
+	commonName := ""
+
+	grpcServer, err := NewGRPCServer(grpcAddress, raftServer, certificateFile, keyFile, commonName, logger)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	defer func() {
+		if err := grpcServer.Stop(); err != nil {
+			t.Fatalf("%v", err)
+		}
+	}()
+
+	if err := grpcServer.Start(); err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	time.Sleep(3 * time.Second)
+}
diff --git a/server/grpc_service_test.go b/server/grpc_service_test.go
new file mode 100644
index 0000000..105841f
--- /dev/null
+++ b/server/grpc_service_test.go
@@ -0,0 +1,811 @@
+package server
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/hashicorp/raft"
+
+	"github.com/mosuka/blast/protobuf"
+
+	"github.com/golang/protobuf/ptypes/empty"
+	"github.com/mosuka/blast/log"
+	"github.com/mosuka/blast/mapping"
+	"github.com/mosuka/blast/util"
+)
+
+func Test_GRPCService_Start_Stop(t *testing.T) {
+	curDir, err := os.Getwd()
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	tmpDir := util.TmpDir()
+	defer func() {
+		_ = os.RemoveAll(tmpDir)
+	}()
+
+	logger := log.NewLogger("WARN", "", 500, 3, 30, false)
+
+	// Raft server
+	rafAddress := fmt.Sprintf(":%d", util.TmpPort())
+	dir := util.TmpDir()
+	defer func() {
+		_ = os.RemoveAll(dir)
+	}()
+	indexMapping, err := mapping.NewIndexMappingFromFile(filepath.Join(curDir, "../examples/example_mapping.json"))
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	raftServer, err := NewRaftServer("node1", rafAddress, dir, indexMapping, true, logger)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	defer func() {
+		if err := raftServer.Stop(); err != nil {
+			t.Fatalf("%v", err)
+		}
+	}()
+	if err := raftServer.Start(); err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	// gRPC service
+	certificateFile := ""
+	commonName := ""
+
+	grpcService, err := NewGRPCService(raftServer, certificateFile, commonName, logger)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	defer func() {
+		if err := grpcService.Stop(); err != nil {
+			t.Fatalf("%v", err)
+		}
+	}()
+
+	if err := grpcService.Start(); err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	time.Sleep(3 * time.Second)
+}
+
+func Test_GRPCService_LivenessCheck(t *testing.T) {
+	curDir, err := os.Getwd()
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	tmpDir := util.TmpDir()
+	defer func() {
+		_ = os.RemoveAll(tmpDir)
+	}()
+
+	logger := log.NewLogger("WARN", "", 500, 3, 30, false)
+
+	// Raft server
+	rafAddress := fmt.Sprintf(":%d", util.TmpPort())
+	dir := util.TmpDir()
+	defer func() {
+		_ = os.RemoveAll(dir)
+	}()
+	indexMapping, err := mapping.NewIndexMappingFromFile(filepath.Join(curDir, "../examples/example_mapping.json"))
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	raftServer, err := NewRaftServer("node1", rafAddress, dir, indexMapping, true, logger)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	defer func() {
+		if err := raftServer.Stop(); err != nil {
+			t.Fatalf("%v", err)
+		}
+	}()
+	if err := raftServer.Start(); err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	// gRPC service
+	certificateFile := ""
+	commonName := ""
+
+	grpcService, err := NewGRPCService(raftServer, certificateFile, commonName, logger)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	defer func() {
+		if err := grpcService.Stop(); err != nil {
+			t.Fatalf("%v", err)
+		}
+	}()
+
+	if err := grpcService.Start(); err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	time.Sleep(3 * time.Second)
+
+	ctx := context.Background()
+	req := &empty.Empty{}
+
+	resp, err := grpcService.LivenessCheck(ctx, req)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	if !resp.Alive {
+		t.Fatalf("expected content to see %v, saw %v", true, resp.Alive)
+	}
+}
+
+func Test_GRPCService_ReadinessCheck(t *testing.T) {
+	curDir, err := os.Getwd()
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	tmpDir := util.TmpDir()
+	defer func() {
+		_ = os.RemoveAll(tmpDir)
+	}()
+
+	logger := log.NewLogger("WARN", "", 500, 3, 30, false)
+
+	// Raft server
+	rafAddress := fmt.Sprintf(":%d", util.TmpPort())
+	dir := util.TmpDir()
+	defer func() {
+		_ = os.RemoveAll(dir)
+	}()
+	indexMapping, err := mapping.NewIndexMappingFromFile(filepath.Join(curDir, "../examples/example_mapping.json"))
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	raftServer, err := NewRaftServer("node1", rafAddress, dir, indexMapping, true, logger)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	defer func() {
+		if err := raftServer.Stop(); err != nil {
+			t.Fatalf("%v", err)
+		}
+	}()
+	if err := raftServer.Start(); err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	// gRPC service
+	certificateFile := ""
+	commonName := ""
+
+	grpcService, err := NewGRPCService(raftServer, certificateFile, commonName, logger)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	defer func() {
+		if err := grpcService.Stop(); err != nil {
+			t.Fatalf("%v", err)
+		}
+	}()
+
+	if err := grpcService.Start(); err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	time.Sleep(3 * time.Second)
+
+	ctx := context.Background()
+	req := &empty.Empty{}
+
+	resp, err := grpcService.ReadinessCheck(ctx, req)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	if !resp.Ready {
+		t.Fatalf("expected content to see %v, saw %v", true, resp.Ready)
+	}
+}
+
+func Test_GRPCService_Join(t *testing.T) {
+	curDir, err := os.Getwd()
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	tmpDir := util.TmpDir()
+	defer func() {
+		_ = os.RemoveAll(tmpDir)
+	}()
+
+	logger := log.NewLogger("WARN", "", 500, 3, 30, false)
+
+	// Raft server
+	raftAddress := fmt.Sprintf(":%d", util.TmpPort())
+	dir := util.TmpDir()
+	defer func() {
+		_ = os.RemoveAll(dir)
+	}()
+	indexMapping, err := mapping.NewIndexMappingFromFile(filepath.Join(curDir, "../examples/example_mapping.json"))
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	raftServer, err := NewRaftServer("node1", raftAddress, dir, indexMapping, true, logger)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	defer func() {
+		if err := raftServer.Stop(); err != nil {
+			t.Fatalf("%v", err)
+		}
+	}()
+	if err := raftServer.Start(); err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	// gRPC service
+	certificateFile := ""
+	commonName := ""
+
+	grpcService, err := NewGRPCService(raftServer, certificateFile, commonName, logger)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	defer func() {
+		if err := grpcService.Stop(); err != nil {
+			t.Fatalf("%v", err)
+		}
+	}()
+
+	if err := grpcService.Start(); err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	time.Sleep(3 * time.Second)
+
+	grpcAddress := fmt.Sprintf(":%d", util.TmpPort())
+	httpAddress := fmt.Sprintf(":%d", util.TmpPort())
+
+	ctx := context.Background()
+	req := &protobuf.JoinRequest{
+		Id: "node1",
+		Node: &protobuf.Node{
+			RaftAddress: raftAddress,
+			Metadata: &protobuf.Metadata{
+				GrpcAddress: grpcAddress,
+				HttpAddress: httpAddress,
+			},
+		},
+	}
+
+	_, err = grpcService.Join(ctx, req)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+}
+
+func Test_GRPCService_Node(t *testing.T) {
+	curDir, err := os.Getwd()
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	tmpDir := util.TmpDir()
+	defer func() {
+		_ = os.RemoveAll(tmpDir)
+	}()
+
+	logger := log.NewLogger("WARN", "", 500, 3, 30, false)
+
+	// Raft server
+	raftAddress := fmt.Sprintf(":%d", util.TmpPort())
+	dir := util.TmpDir()
+	defer func() {
+		_ = os.RemoveAll(dir)
+	}()
+	indexMapping, err := mapping.NewIndexMappingFromFile(filepath.Join(curDir, "../examples/example_mapping.json"))
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	raftServer, err := NewRaftServer("node1", raftAddress, dir, indexMapping, true, logger)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	defer func() {
+		if err := raftServer.Stop(); err != nil {
+			t.Fatalf("%v", err)
+		}
+	}()
+	if err := raftServer.Start(); err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	// gRPC service
+	certificateFile := ""
+	commonName := ""
+
+	grpcService, err := NewGRPCService(raftServer, certificateFile, commonName, logger)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	defer func() {
+		if err := grpcService.Stop(); err != nil {
+			t.Fatalf("%v", err)
+		}
+	}()
+
+	if err := grpcService.Start(); err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	time.Sleep(3 * time.Second)
+
+	grpcAddress := fmt.Sprintf(":%d", util.TmpPort())
+	httpAddress := fmt.Sprintf(":%d", util.TmpPort())
+
+	ctx := context.Background()
+	req := &protobuf.JoinRequest{
+		Id: "node1",
+		Node: &protobuf.Node{
+			RaftAddress: raftAddress,
+			Metadata: &protobuf.Metadata{
+				GrpcAddress: grpcAddress,
+				HttpAddress: httpAddress,
+			},
+		},
+	}
+
+	_, err = grpcService.Join(ctx, req)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	resp, err := grpcService.Node(ctx, &empty.Empty{})
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	if raftAddress != resp.Node.RaftAddress {
+		t.Fatalf("expected content to see %v, saw %v", raftAddress, resp.Node.RaftAddress)
+	}
+
+	if grpcAddress != resp.Node.Metadata.GrpcAddress {
+		t.Fatalf("expected content to see %v, saw %v", grpcAddress, resp.Node.Metadata.GrpcAddress)
+	}
+
+	if httpAddress != resp.Node.Metadata.HttpAddress {
+		t.Fatalf("expected content to see %v, saw %v", grpcAddress, resp.Node.Metadata.HttpAddress)
+	}
+
+	if raft.Leader.String() != resp.Node.State {
+		t.Fatalf("expected content to see %v, saw %v", raft.Leader.String(), resp.Node.State)
+	}
+}
+
+//func Test_GRPCService_Leave(t *testing.T) {
+//	curDir, err := os.Getwd()
+//	if err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//
+//	tmpDir := util.TmpDir()
+//	defer func() {
+//		_ = os.RemoveAll(tmpDir)
+//	}()
+//
+//	logger := log.NewLogger("WARN", "", 500, 3, 30, false)
+//
+//	certificateFile := ""
+//	commonName := ""
+//
+//	raftAddress1 := fmt.Sprintf(":%d", util.TmpPort())
+//	grpcAddress1 := fmt.Sprintf(":%d", util.TmpPort())
+//	httpAddress1 := fmt.Sprintf(":%d", util.TmpPort())
+//
+//	raftAddress2 := fmt.Sprintf(":%d", util.TmpPort())
+//	grpcAddress2 := fmt.Sprintf(":%d", util.TmpPort())
+//	httpAddress2 := fmt.Sprintf(":%d", util.TmpPort())
+//
+//	raftAddress3 := fmt.Sprintf(":%d", util.TmpPort())
+//	grpcAddress3 := fmt.Sprintf(":%d", util.TmpPort())
+//	httpAddress3 := fmt.Sprintf(":%d", util.TmpPort())
+//
+//	dir1 := util.TmpDir()
+//	defer func() {
+//		_ = os.RemoveAll(dir1)
+//	}()
+//	dir2 := util.TmpDir()
+//	defer func() {
+//		_ = os.RemoveAll(dir2)
+//	}()
+//	dir3 := util.TmpDir()
+//	defer func() {
+//		_ = os.RemoveAll(dir3)
+//	}()
+//
+//	indexMapping, err := mapping.NewIndexMappingFromFile(filepath.Join(curDir, "../examples/example_mapping.json"))
+//	if err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//
+//	// Raft server
+//	raftServer1, err := NewRaftServer("node1", raftAddress1, dir1, indexMapping, true, logger)
+//	if err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//	defer func() {
+//		if err := raftServer1.Stop(); err != nil {
+//			t.Fatalf("%v", err)
+//		}
+//	}()
+//	if err := raftServer1.Start(); err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//
+//	raftServer2, err := NewRaftServer("node2", raftAddress2, dir2, indexMapping, false, logger)
+//	if err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//	defer func() {
+//		if err := raftServer2.Stop(); err != nil {
+//			t.Fatalf("%v", err)
+//		}
+//	}()
+//	if err := raftServer2.Start(); err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//
+//	raftServer3, err := NewRaftServer("node3", raftAddress3, dir3, indexMapping, false, logger)
+//	if err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//	defer func() {
+//		if err := raftServer3.Stop(); err != nil {
+//			t.Fatalf("%v", err)
+//		}
+//	}()
+//	if err := raftServer3.Start(); err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//
+//	// gRPC service
+//	grpcService1, err := NewGRPCService(raftServer1, certificateFile, commonName, logger)
+//	if err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//	defer func() {
+//		if err := grpcService1.Stop(); err != nil {
+//			t.Fatalf("%v", err)
+//		}
+//	}()
+//	if err := grpcService1.Start(); err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//
+//	grpcService2, err := NewGRPCService(raftServer2, certificateFile, commonName, logger)
+//	if err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//	defer func() {
+//		if err := grpcService2.Stop(); err != nil {
+//			t.Fatalf("%v", err)
+//		}
+//	}()
+//	if err := grpcService2.Start(); err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//
+//	grpcService3, err := NewGRPCService(raftServer3, certificateFile, commonName, logger)
+//	if err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//	defer func() {
+//		if err := grpcService3.Stop(); err != nil {
+//			t.Fatalf("%v", err)
+//		}
+//	}()
+//	if err := grpcService3.Start(); err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//
+//	time.Sleep(3 * time.Second)
+//
+//	ctx := context.Background()
+//	req1 := &protobuf.JoinRequest{
+//		Id: "node1",
+//		Node: &protobuf.Node{
+//			RaftAddress: raftAddress1,
+//			Metadata: &protobuf.Metadata{
+//				GrpcAddress: grpcAddress1,
+//				HttpAddress: httpAddress1,
+//			},
+//		},
+//	}
+//	_, err = grpcService1.Join(ctx, req1)
+//	if err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//
+//	req2 := &protobuf.JoinRequest{
+//		Id: "node2",
+//		Node: &protobuf.Node{
+//			RaftAddress: raftAddress2,
+//			Metadata: &protobuf.Metadata{
+//				GrpcAddress: grpcAddress2,
+//				HttpAddress: httpAddress2,
+//			},
+//		},
+//	}
+//	_, err = grpcService1.Join(ctx, req2)
+//	if err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//
+//	req3 := &protobuf.JoinRequest{
+//		Id: "node3",
+//		Node: &protobuf.Node{
+//			RaftAddress: raftAddress3,
+//			Metadata: &protobuf.Metadata{
+//				GrpcAddress: grpcAddress3,
+//				HttpAddress: httpAddress3,
+//			},
+//		},
+//	}
+//	_, err = grpcService1.Join(ctx, req3)
+//	if err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//
+//	resp, err := grpcService1.Cluster(ctx, &empty.Empty{})
+//	if err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//
+//	if "node1" != resp.Cluster.Leader {
+//		t.Fatalf("expected content to see %v, saw %v", "node1", resp.Cluster.Leader)
+//	}
+//
+//	//if raftAddress1 != resp..RaftAddress {
+//	//	t.Fatalf("expected content to see %v, saw %v", raftAddress1, resp.Node.RaftAddress)
+//	//}
+//	//
+//	//if grpcAddress1 != resp.Node.Metadata.GrpcAddress {
+//	//	t.Fatalf("expected content to see %v, saw %v", grpcAddress1, resp.Node.Metadata.GrpcAddress)
+//	//}
+//	//
+//	//if httpAddress1 != resp.Node.Metadata.HttpAddress {
+//	//	t.Fatalf("expected content to see %v, saw %v", grpcAddress1, resp.Node.Metadata.HttpAddress)
+//	//}
+//	//
+//	//if raft.Leader.String() != resp.Node.State {
+//	//	t.Fatalf("expected content to see %v, saw %v", raft.Leader.String(), resp.Node.State)
+//	//}
+//}
+
+//func Test_GRPCService_Cluster(t *testing.T) {
+//	curDir, err := os.Getwd()
+//	if err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//
+//	tmpDir := util.TmpDir()
+//	defer func() {
+//		_ = os.RemoveAll(tmpDir)
+//	}()
+//
+//	// Raft server
+//	raftAddress1 := fmt.Sprintf(":%d", util.TmpPort())
+//	dir1 := util.TmpDir()
+//	defer func() {
+//		_ = os.RemoveAll(dir1)
+//	}()
+//	indexMapping1, err := mapping.NewIndexMappingFromFile(filepath.Join(curDir, "../examples/example_mapping.json"))
+//	if err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//	logger1 := log.NewLogger("WARN", "", 500, 3, 30, false)
+//	raftServer1, err := NewRaftServer("node1", raftAddress1, dir1, indexMapping1, true, logger1)
+//	if err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//	defer func() {
+//		if err := raftServer1.Stop(); err != nil {
+//			t.Fatalf("%v", err)
+//		}
+//	}()
+//	if err := raftServer1.Start(); err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//
+//	// gRPC service
+//	certificateFile1 := ""
+//	commonName1 := ""
+//	grpcService1, err := NewGRPCService(raftServer1, certificateFile1, commonName1, logger1)
+//	if err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//	defer func() {
+//		if err := grpcService1.Stop(); err != nil {
+//			t.Fatalf("%v", err)
+//		}
+//	}()
+//
+//	if err := grpcService1.Start(); err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//
+//	time.Sleep(3 * time.Second)
+//
+//	grpcAddress1 := fmt.Sprintf(":%d", util.TmpPort())
+//	httpAddress1 := fmt.Sprintf(":%d", util.TmpPort())
+//
+//	ctx1 := context.Background()
+//	joinReq1 := &protobuf.JoinRequest{
+//		Id: "node1",
+//		Node: &protobuf.Node{
+//			RaftAddress: raftAddress1,
+//			Metadata: &protobuf.Metadata{
+//				GrpcAddress: grpcAddress1,
+//				HttpAddress: httpAddress1,
+//			},
+//		},
+//	}
+//	_, err = grpcService1.Join(ctx1, joinReq1)
+//	if err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//
+//	// Raft server
+//	raftAddress2 := fmt.Sprintf(":%d", util.TmpPort())
+//	dir2 := util.TmpDir()
+//	defer func() {
+//		_ = os.RemoveAll(dir2)
+//	}()
+//	indexMapping2, err := mapping.NewIndexMappingFromFile(filepath.Join(curDir, "../examples/example_mapping.json"))
+//	if err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//	logger2 := log.NewLogger("WARN", "", 500, 3, 30, false)
+//	raftServer2, err := NewRaftServer("node2", raftAddress2, dir2, indexMapping2, false, logger2)
+//	if err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//	defer func() {
+//		if err := raftServer2.Stop(); err != nil {
+//			t.Fatalf("%v", err)
+//		}
+//	}()
+//	if err := raftServer2.Start(); err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//
+//	// gRPC service
+//	certificateFile2 := ""
+//	commonName2 := ""
+//	grpcService2, err := NewGRPCService(raftServer2, certificateFile2, commonName2, logger2)
+//	if err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//	defer func() {
+//		if err := grpcService2.Stop(); err != nil {
+//			t.Fatalf("%v", err)
+//		}
+//	}()
+//
+//	if err := grpcService2.Start(); err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//
+//	time.Sleep(3 * time.Second)
+//
+//	grpcAddress2 := fmt.Sprintf(":%d", util.TmpPort())
+//	httpAddress2 := fmt.Sprintf(":%d", util.TmpPort())
+//
+//	ctx2 := context.Background()
+//	joinReq2 := &protobuf.JoinRequest{
+//		Id: "node2",
+//		Node: &protobuf.Node{
+//			RaftAddress: raftAddress2,
+//			Metadata: &protobuf.Metadata{
+//				GrpcAddress: grpcAddress2,
+//				HttpAddress: httpAddress2,
+//			},
+//		},
+//	}
+//	_, err = grpcService1.Join(ctx2, joinReq2)
+//	if err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//
+//	// Raft server
+//	raftAddress3 := fmt.Sprintf(":%d", util.TmpPort())
+//	dir3 := util.TmpDir()
+//	defer func() {
+//		_ = os.RemoveAll(dir3)
+//	}()
+//	indexMapping3, err := mapping.NewIndexMappingFromFile(filepath.Join(curDir, "../examples/example_mapping.json"))
+//	if err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//	logger3 := log.NewLogger("WARN", "", 500, 3, 30, false)
+//	raftServer3, err := NewRaftServer("node3", raftAddress3, dir3, indexMapping3, false, logger3)
+//	if err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//	defer func() {
+//		if err := raftServer3.Stop(); err != nil {
+//			t.Fatalf("%v", err)
+//		}
+//	}()
+//	if err := raftServer3.Start(); err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//
+//	// gRPC service
+//	certificateFile3 := ""
+//	commonName3 := ""
+//	grpcService3, err := NewGRPCService(raftServer3, certificateFile3, commonName3, logger3)
+//	if err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//	defer func() {
+//		if err := grpcService3.Stop(); err != nil {
+//			t.Fatalf("%v", err)
+//		}
+//	}()
+//
+//	if err := grpcService3.Start(); err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//
+//	time.Sleep(3 * time.Second)
+//
+//	grpcAddress3 := fmt.Sprintf(":%d", util.TmpPort())
+//	httpAddress3 := fmt.Sprintf(":%d", util.TmpPort())
+//
+//	ctx3 := context.Background()
+//	joinReq3 := &protobuf.JoinRequest{
+//		Id: "node3",
+//		Node: &protobuf.Node{
+//			RaftAddress: raftAddress3,
+//			Metadata: &protobuf.Metadata{
+//				GrpcAddress: grpcAddress3,
+//				HttpAddress: httpAddress3,
+//			},
+//		},
+//	}
+//	_, err = grpcService1.Join(ctx3, joinReq3)
+//	if err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//
+//	respCluster1, err := grpcService1.Cluster(ctx1, &empty.Empty{})
+//	if err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//	if 3 != len(respCluster1.Cluster.Nodes) {
+//		t.Fatalf("expected content to see %v, saw %v", 3, len(respCluster1.Cluster.Nodes))
+//	}
+//
+//	respCluster2, err := grpcService2.Cluster(ctx2, &empty.Empty{})
+//	if err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//	if 3 != len(respCluster2.Cluster.Nodes) {
+//		t.Fatalf("expected content to see %v, saw %v", 3, len(respCluster2.Cluster.Nodes))
+//	}
+//
+//	respCluster3, err := grpcService2.Cluster(ctx3, &empty.Empty{})
+//	if err != nil {
+//		t.Fatalf("%v", err)
+//	}
+//	if 3 != len(respCluster3.Cluster.Nodes) {
+//		t.Fatalf("expected content to see %v, saw %v", 3, len(respCluster3.Cluster.Nodes))
+//	}
+//}