From ec2de5c78f50001af3ff07be9a2adf476575e121 Mon Sep 17 00:00:00 2001
From: Chao Chen <chaochn@amazon.com>
Date: Thu, 14 Sep 2023 13:05:01 -0700
Subject: [PATCH] tests/e2e: add client failover tests on network partition,
 stalled disk and online defrag

Signed-off-by: Chao Chen <chaochn@amazon.com>
---
 tests/e2e/failover_test.go | 163 +++++++++++++++++++++++++++++++++++++
 1 file changed, 163 insertions(+)
 create mode 100644 tests/e2e/failover_test.go

diff --git a/tests/e2e/failover_test.go b/tests/e2e/failover_test.go
new file mode 100644
index 000000000000..7335acc18f8f
--- /dev/null
+++ b/tests/e2e/failover_test.go
@@ -0,0 +1,163 @@
+// Copyright 2023 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.
+
+//go:build !cluster_proxy
+
+package e2e
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+	"google.golang.org/grpc"
+	_ "google.golang.org/grpc/health"
+
+	clientv3 "go.etcd.io/etcd/client/v3"
+	"go.etcd.io/etcd/tests/v3/framework/config"
+	"go.etcd.io/etcd/tests/v3/framework/e2e"
+)
+
+const (
+	// in sync with how kubernetes uses etcd
+	// https://github.com/kubernetes/kubernetes/blob/release-1.28/staging/src/k8s.io/apiserver/pkg/storage/storagebackend/factory/etcd3.go#L59-L71
+	keepaliveTime    = 30 * time.Second
+	keepaliveTimeout = 10 * time.Second
+	dialTimeout      = 20 * time.Second
+
+	clientRuntime           = 10 * time.Second
+	failureDetectionLatency = 6 * time.Second
+	// expect no more than 5 failed requests
+	failedRequests = 5
+)
+
+func TestFailover(t *testing.T) {
+	tcs := []struct {
+		name                    string
+		clusterOptions          []e2e.EPClusterOption
+		failureInjector         func(t *testing.T, clus *e2e.EtcdProcessCluster)
+		failureDetectionLatency time.Duration
+	}{
+		{
+			name:                    "network_partition",
+			clusterOptions:          []e2e.EPClusterOption{e2e.WithClusterSize(3), e2e.WithIsPeerTLS(true), e2e.WithPeerProxy(true)},
+			failureInjector:         blackhole,
+			failureDetectionLatency: failureDetectionLatency,
+		},
+		{
+			name:                    "stalled_disk_write",
+			clusterOptions:          []e2e.EPClusterOption{e2e.WithClusterSize(3), e2e.WithGoFailEnabled(true)},
+			failureInjector:         blockDiskWrite,
+			failureDetectionLatency: failureDetectionLatency,
+		},
+		{
+			name:            "defrag",
+			clusterOptions:  []e2e.EPClusterOption{e2e.WithClusterSize(3), e2e.WithGoFailEnabled(true)},
+			failureInjector: triggerDefrag,
+		},
+	}
+
+	for _, tc := range tcs {
+		t.Run(tc.name, func(t *testing.T) {
+			e2e.BeforeTest(t)
+			clus, err := e2e.NewEtcdProcessCluster(context.TODO(), t, tc.clusterOptions...)
+			t.Cleanup(func() { clus.Stop() })
+			endpoints := clus.EndpointsGRPC()
+
+			cnt, success := 0, 0
+			donec := make(chan struct{})
+			errc := make(chan error, 1)
+
+			go func() {
+				var lastErr error
+				var cc *clientv3.Client
+				defer func() {
+					if cc != nil {
+						cc.Close()
+					}
+					errc <- lastErr
+					close(donec)
+					close(errc)
+				}()
+				cc, cerr := clientv3.New(clientv3.Config{
+					DialTimeout:          dialTimeout,
+					DialKeepAliveTime:    keepaliveTime,
+					DialKeepAliveTimeout: keepaliveTimeout,
+					Endpoints:            endpoints,
+					DialOptions: []grpc.DialOption{
+						grpc.WithDisableServiceConfig(),
+						grpc.WithDefaultServiceConfig(`{"loadBalancingPolicy": "round_robin", "healthCheckConfig": {"serviceName": ""}}`),
+						// the following service config will disable grpc client health check
+						//grpc.WithDefaultServiceConfig(`{"loadBalancingPolicy": "round_robin"}`),
+					},
+				})
+				require.NoError(t, cerr)
+				timeout := time.After(clientRuntime)
+
+				time.Sleep(tc.failureDetectionLatency)
+				for {
+					select {
+					case <-timeout:
+						return
+					default:
+					}
+					cctx, cancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
+					//start := time.Now()
+					_, err = cc.Get(cctx, "health")
+					//t.Logf("TS (%s): number #%d health check took %v", time.Now().UTC().Format(time.RFC3339), cnt, time.Since(start))
+					cancel()
+					cnt++
+					if err != nil {
+						lastErr = err
+						continue
+					}
+					success++
+				}
+			}()
+
+			tc.failureInjector(t, clus)
+
+			<-donec
+			err, ok := <-errc
+			if ok && err != nil {
+				t.Logf("etcd client failed to fail over, error (%v)", err)
+			}
+			t.Logf("request failure rate is %.2f%%, traffic volume success %d requests, total %d requests", (1-float64(success)/float64(cnt))*100, success, cnt)
+			// expect no more than 5 failed requests
+			require.InDelta(t, cnt, success, failedRequests)
+		})
+	}
+}
+
+func blackhole(t *testing.T, clus *e2e.EtcdProcessCluster) {
+	member := clus.Procs[0]
+	proxy := member.PeerProxy()
+	t.Logf("Blackholing traffic from and to member %q", member.Config().Name)
+	proxy.BlackholeTx()
+	proxy.BlackholeRx()
+}
+
+func blockDiskWrite(t *testing.T, clus *e2e.EtcdProcessCluster) {
+	err := clus.Procs[0].Failpoints().Setup(context.Background(), "raftBeforeSave", `sleep(10000)`)
+	require.NoError(t, err)
+	clus.Procs[0].Etcdctl().Put(context.Background(), "foo", "bar", config.PutOptions{})
+}
+
+func triggerDefrag(t *testing.T, clus *e2e.EtcdProcessCluster) {
+	err := clus.Procs[0].Failpoints().Setup(context.Background(), "defragBeforeCopy", `sleep(8000)`)
+	require.NoError(t, err)
+	err = clus.Procs[0].Etcdctl().Defragment(context.Background(), config.DefragOption{Timeout: time.Minute})
+	require.NoError(t, err)
+}