*: remove the previous joined pd (tikv#8562)

close tikv#7954

Signed-off-by: Ryan Leung <rleungx@gmail.com>

tests/cluster.go

@@ -611,6 +611,11 @@ func (c *TestCluster) StopAll() error {
 	return nil
 }
 
+// DeleteServer is used to delete a server.
+func (c *TestCluster) DeleteServer(name string) {
+	delete(c.servers, name)
+}
+
 // GetServer returns a server with a given name.
 func (c *TestCluster) GetServer(name string) *TestServer {
 	return c.servers[name]

tests/integrations/mcs/scheduling/api_test.go

@@ -513,6 +513,20 @@ func (suite *apiTestSuite) checkFollowerForward(cluster *tests.TestCluster) {
 	defer cancel()
 	follower, err := cluster.JoinAPIServer(ctx)
 	re.NoError(err)
+	defer func() {
+		leader := cluster.GetLeaderServer()
+		cli := leader.GetEtcdClient()
+		testutil.Eventually(re, func() bool {
+			_, err = cli.MemberRemove(context.Background(), follower.GetServer().GetMember().ID())
+			return err == nil
+		})
+		testutil.Eventually(re, func() bool {
+			res, err := cli.MemberList(context.Background())
+			return err == nil && len(res.Members) == 1
+		})
+		cluster.DeleteServer(follower.GetConfig().Name)
+		follower.Destroy()
+	}()
 	re.NoError(follower.Run())
 	re.NotEmpty(cluster.WaitLeader())