clientv3/integration: add TestWatchKeepAlive

Signed-off-by: Gyu-Ho Lee <gyuhox@gmail.com>

clientv3/integration/watch_keepalive_test.go

@@ -0,0 +1,94 @@
+// Copyright 2017 The etcd Authors
+//
+// 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.
+
+// +build !cluster_proxy
+
+package integration
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/coreos/etcd/clientv3"
+	"github.com/coreos/etcd/integration"
+	"github.com/coreos/etcd/pkg/testutil"
+)
+
+// TestWatchKeepAlive tests when watch discovers it cannot talk to
+// blackholed endpoint, client balancer switches to healthy one.
+// TODO: test server-to-client ping
+func TestWatchKeepAlive(t *testing.T) {
+	defer testutil.AfterTest(t)
+
+	clus := integration.NewClusterV3(t, &integration.ClusterConfig{
+		Size:                  3,
+		GRPCKeepAliveMinTime:  time.Millisecond, // avoid too_many_pings
+		GRPCKeepAliveInterval: 2 * time.Second,  // server-to-client ping
+		GRPCKeepAliveTimeout:  2 * time.Second,
+	})
+	defer clus.Terminate(t)
+
+	ccfg := clientv3.Config{
+		Endpoints:            []string{clus.Members[0].GRPCAddr()},
+		DialTimeout:          3 * time.Second,
+		DialKeepAliveTime:    2 * time.Second,
+		DialKeepAliveTimeout: 2 * time.Second,
+	}
+	cli, err := clientv3.New(ccfg)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer cli.Close()
+
+	wch := cli.Watch(context.Background(), "foo", clientv3.WithCreatedNotify())
+	if _, ok := <-wch; !ok {
+		t.Fatalf("watch failed on creation")
+	}
+
+	clus.Members[0].Blackhole()
+
+	// trigger gRPC to close ep[0], and switch to ep[1]
+	cli.SetEndpoints(clus.Members[0].GRPCAddr(), clus.Members[1].GRPCAddr())
+
+	// ep[0] keepalive time-out after DialKeepAliveTime + DialKeepAliveTimeout
+	// wait extra for processing network error for endpoint switching
+	timeout := ccfg.DialKeepAliveTime + ccfg.DialKeepAliveTimeout + ccfg.DialTimeout
+	time.Sleep(timeout)
+
+	if _, err = clus.Client(1).Put(context.TODO(), "foo", "bar"); err != nil {
+		t.Fatal(err)
+	}
+	select {
+	case <-wch:
+	case <-time.After(5 * time.Second):
+		t.Fatal("took too long to receive events")
+	}
+
+	clus.Members[0].Unblackhole()
+	clus.Members[1].Blackhole()
+	defer clus.Members[1].Unblackhole()
+
+	// wait for ep[0] recover, ep[1] fail
+	time.Sleep(timeout)
+
+	if _, err = clus.Client(0).Put(context.TODO(), "foo", "bar"); err != nil {
+		t.Fatal(err)
+	}
+	select {
+	case <-wch:
+	case <-time.After(5 * time.Second):
+		t.Fatal("took too long to receive events")
+	}
+}