Close WatchDocument stream on agent shutdown (yorkie-team#210)

test/integration/agent_test.go

@@ -0,0 +1,75 @@
+// +build integration
+
+/*
+ * Copyright 2021 The Yorkie Authors. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package integration
+
+import (
+	"context"
+	"io"
+	"sync"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+
+	"github.com/yorkie-team/yorkie/client"
+	"github.com/yorkie-team/yorkie/pkg/document"
+	"github.com/yorkie-team/yorkie/test/helper"
+)
+
+func TestAgent(t *testing.T) {
+	t.Run("closing WatchDocument stream on agent shutdown test", func(t *testing.T) {
+		ctx := context.Background()
+		agent := helper.TestYorkie()
+		assert.NoError(t, agent.Start())
+
+		cli, err := client.Dial(agent.RPCAddr())
+		assert.NoError(t, err)
+		assert.NoError(t, cli.Activate(ctx))
+
+		doc := document.New(helper.Collection, t.Name())
+		assert.NoError(t, cli.Attach(ctx, doc))
+
+		wg := sync.WaitGroup{}
+		wrch := cli.Watch(ctx, doc)
+
+		go func() {
+			for {
+				select {
+				case <-ctx.Done():
+					assert.Fail(t, "unexpected ctx done")
+					return
+				case wr := <-wrch:
+					if wr.Err == io.EOF || status.Code(wr.Err) == codes.Canceled {
+						peers := wr.PeersMapByDoc[doc.Key().BSONKey()]
+						assert.Len(t, peers, 0)
+						wg.Done()
+						return
+					}
+				}
+			}
+		}()
+
+		wg.Add(1)
+		assert.NoError(t, agent.Shutdown(true))
+
+		wg.Wait()
+	})
+}
+

yorkie/rpc/server.go

@@ -17,6 +17,7 @@
 package rpc
 
 import (
+	"context"
 	"fmt"
 	"net"
 
@@ -42,8 +43,9 @@ type Config struct {
 
 // Server is a normal server that processes the logic requested by the client.
 type Server struct {
-	conf       *Config
-	grpcServer *grpc.Server
+	conf                *Config
+	grpcServer          *grpc.Server
+	yorkieServiceCancel context.CancelFunc
 }
 
 // NewServer creates a new instance of Server.
@@ -73,15 +75,18 @@ func NewServer(conf *Config, be *backend.Backend) (*Server, error) {
 		opts = append(opts, grpc.Creds(creds))
 	}
 
+	yorkieServiceCtx, yorkieServiceCancel := context.WithCancel(context.Background())
+
 	grpcServer := grpc.NewServer(opts...)
 	healthpb.RegisterHealthServer(grpcServer, health.NewServer())
-	api.RegisterYorkieServer(grpcServer, newYorkieServer(be))
+	api.RegisterYorkieServer(grpcServer, newYorkieServer(yorkieServiceCtx, be))
 	api.RegisterClusterServer(grpcServer, newClusterServer(be))
 	grpcprometheus.Register(grpcServer)
 
 	return &Server{
-		conf:       conf,
-		grpcServer: grpcServer,
+		conf:                conf,
+		grpcServer:          grpcServer,
+		yorkieServiceCancel: yorkieServiceCancel,
 	}, nil
 }
 
@@ -92,6 +97,8 @@ func (s *Server) Start() error {
 
 // Shutdown shuts down this server.
 func (s *Server) Shutdown(graceful bool) {
+	s.yorkieServiceCancel()
+
 	if graceful {
 		s.grpcServer.GracefulStop()
 	} else {

yorkie/rpc/yorkie_server.go

@@ -33,12 +33,16 @@ import (
 )
 
 type yorkieServer struct {
-	backend *backend.Backend
+	backend    *backend.Backend
+	serviceCtx context.Context
 }
 
 // newYorkieServer creates a new instance of yorkieServer
-func newYorkieServer(be *backend.Backend) *yorkieServer {
-	return &yorkieServer{backend: be}
+func newYorkieServer(serviceCtx context.Context, be *backend.Backend) *yorkieServer {
+	return &yorkieServer{
+		backend:    be,
+		serviceCtx: serviceCtx,
+	}
 }
 
 // ActivateClient activates the given client.
@@ -320,7 +324,6 @@ func (s *yorkieServer) WatchDocuments(
 		return err
 	}
 
-	// TODO(hackerwins): unwatchDocs when shutting down the agent.
 	if err := stream.Send(&api.WatchDocumentsResponse{
 		Body: &api.WatchDocumentsResponse_Initialization_{
 			Initialization: &api.WatchDocumentsResponse_Initialization{
@@ -335,6 +338,9 @@ func (s *yorkieServer) WatchDocuments(
 
 	for {
 		select {
+		case <-s.serviceCtx.Done():
+			s.unwatchDocs(docKeys, subscription)
+			return nil
 		case <-stream.Context().Done():
 			s.unwatchDocs(docKeys, subscription)
 			return nil