func TestTabletExternallyReparentedFailedOldMaster(t *testing.T) {
	tabletmanager.SetReparentFlags(time.Minute /* finalizeTimeout */)

	ctx := context.Background()
	ts := zktopo.NewTestServer(t, []string{"cell1", "cell2"})
	wr := wrangler.New(logutil.NewConsoleLogger(), ts, tmclient.NewTabletManagerClient(), time.Second)

	// Create an old master, a new master, and a good slave.
	oldMaster := NewFakeTablet(t, wr, "cell1", 0, topo.TYPE_MASTER)
	newMaster := NewFakeTablet(t, wr, "cell1", 1, topo.TYPE_REPLICA)
	goodSlave := NewFakeTablet(t, wr, "cell1", 2, topo.TYPE_REPLICA)

	// Reparent to a replica, and pretend the old master is not responding.

	// On the elected master, we will respond to
	// TabletActionSlaveWasPromoted
	newMaster.StartActionLoop(t, wr)
	defer newMaster.StopActionLoop(t)

	// On the old master, we will only get a
	// TabletActionSlaveWasRestarted call, let's just not
	// respond to it at all

	// On the good slave, we will respond to
	// TabletActionSlaveWasRestarted.
	goodSlave.StartActionLoop(t, wr)
	defer goodSlave.StopActionLoop(t)

	// The reparent should work as expected here
	t.Logf("TabletExternallyReparented(new master) expecting success")
	tmc := tmclient.NewTabletManagerClient()
	ti, err := ts.GetTablet(ctx, newMaster.Tablet.Alias)
	if err != nil {
		t.Fatalf("GetTablet failed: %v", err)
	}
	waitID := makeWaitID()
	if err := tmc.TabletExternallyReparented(context.Background(), ti, waitID); err != nil {
		t.Fatalf("TabletExternallyReparented(replica) failed: %v", err)
	}
	waitForExternalReparent(t, waitID)

	// Now double-check the serving graph is good.
	// Should only have one good replica left.
	addrs, _, err := ts.GetEndPoints(ctx, "cell1", "test_keyspace", "0", topo.TYPE_REPLICA)
	if err != nil {
		t.Fatalf("GetEndPoints failed at the end: %v", err)
	}
	if len(addrs.Entries) != 1 {
		t.Fatalf("GetEndPoints has too many entries: %v", addrs)
	}

	// check the old master was converted to spare
	tablet, err := ts.GetTablet(ctx, oldMaster.Tablet.Alias)
	if err != nil {
		t.Fatalf("GetTablet(%v) failed: %v", oldMaster.Tablet.Alias, err)
	}
	if tablet.Type != topo.TYPE_SPARE {
		t.Fatalf("old master should be spare but is: %v", tablet.Type)
	}
}

func TestTabletExternallyReparentedFailedOldMaster(t *testing.T) {
	tabletmanager.SetReparentFlags(time.Minute /* finalizeTimeout */)

	ctx := context.Background()
	db := fakesqldb.Register()
	ts := zktestserver.New(t, []string{"cell1", "cell2"})
	wr := wrangler.New(logutil.NewConsoleLogger(), ts, tmclient.NewTabletManagerClient())

	// Create an old master, a new master, and a good slave.
	oldMaster := NewFakeTablet(t, wr, "cell1", 0, topodatapb.TabletType_MASTER, db)
	newMaster := NewFakeTablet(t, wr, "cell1", 1, topodatapb.TabletType_REPLICA, db)
	goodSlave := NewFakeTablet(t, wr, "cell1", 2, topodatapb.TabletType_REPLICA, db)

	// Reparent to a replica, and pretend the old master is not responding.

	// On the elected master, we will respond to
	// TabletActionSlaveWasPromoted
	newMaster.StartActionLoop(t, wr)
	defer newMaster.StopActionLoop(t)

	// On the old master, we will only get a
	// TabletActionSlaveWasRestarted call, let's just not
	// respond to it at all

	// On the good slave, we will respond to
	// TabletActionSlaveWasRestarted.
	goodSlave.StartActionLoop(t, wr)
	defer goodSlave.StopActionLoop(t)

	// The reparent should work as expected here
	t.Logf("TabletExternallyReparented(new master) expecting success")
	tmc := tmclient.NewTabletManagerClient()
	ti, err := ts.GetTablet(ctx, newMaster.Tablet.Alias)
	if err != nil {
		t.Fatalf("GetTablet failed: %v", err)
	}
	waitID := makeWaitID()
	if err := tmc.TabletExternallyReparented(context.Background(), ti.Tablet, waitID); err != nil {
		t.Fatalf("TabletExternallyReparented(replica) failed: %v", err)
	}
	waitForExternalReparent(t, waitID)

	// check the old master was converted to replica
	tablet, err := ts.GetTablet(ctx, oldMaster.Tablet.Alias)
	if err != nil {
		t.Fatalf("GetTablet(%v) failed: %v", oldMaster.Tablet.Alias, err)
	}
	if tablet.Type != topodatapb.TabletType_REPLICA {
		t.Fatalf("old master should be spare but is: %v", tablet.Type)
	}
}

// TestTabletExternallyReparentedWithDifferentMysqlPort makes sure
// that if mysql is restarted on the master-elect tablet and has a different
// port, we pick it up correctly.
func TestTabletExternallyReparentedWithDifferentMysqlPort(t *testing.T) {
	tabletmanager.SetReparentFlags(time.Minute /* finalizeTimeout */)

	ctx := context.Background()
	db := fakesqldb.Register()
	ts := zktopo.NewTestServer(t, []string{"cell1"})
	wr := wrangler.New(logutil.NewConsoleLogger(), ts, tmclient.NewTabletManagerClient(), time.Second)

	// Create an old master, a new master, two good slaves, one bad slave
	oldMaster := NewFakeTablet(t, wr, "cell1", 0, pb.TabletType_MASTER, db)
	newMaster := NewFakeTablet(t, wr, "cell1", 1, pb.TabletType_REPLICA, db)
	goodSlave := NewFakeTablet(t, wr, "cell1", 2, pb.TabletType_REPLICA, db)

	// Now we're restarting mysql on a different port, 3301->3303
	// but without updating the Tablet record in topology.

	// On the elected master, we will respond to
	// TabletActionSlaveWasPromoted, so we need a MysqlDaemon
	// that returns no master, and the new port (as returned by mysql)
	newMaster.FakeMysqlDaemon.MysqlPort = 3303
	newMaster.StartActionLoop(t, wr)
	defer newMaster.StopActionLoop(t)

	// On the old master, we will only respond to
	// TabletActionSlaveWasRestarted and point to the new mysql port
	oldMaster.StartActionLoop(t, wr)
	defer oldMaster.StopActionLoop(t)

	// On the good slaves, we will respond to
	// TabletActionSlaveWasRestarted and point to the new mysql port
	goodSlave.StartActionLoop(t, wr)
	defer goodSlave.StopActionLoop(t)

	// This tests the good case, where everything works as planned
	t.Logf("TabletExternallyReparented(new master) expecting success")
	tmc := tmclient.NewTabletManagerClient()
	ti, err := ts.GetTablet(ctx, newMaster.Tablet.Alias)
	if err != nil {
		t.Fatalf("GetTablet failed: %v", err)
	}
	waitID := makeWaitID()
	if err := tmc.TabletExternallyReparented(context.Background(), ti, waitID); err != nil {
		t.Fatalf("TabletExternallyReparented(replica) failed: %v", err)
	}
	waitForExternalReparent(t, waitID)
}

// TestTabletExternallyReparentedContinueOnUnexpectedMaster makes sure
// that we ignore mysql's master if the flag is set
func TestTabletExternallyReparentedContinueOnUnexpectedMaster(t *testing.T) {
	tabletmanager.SetReparentFlags(time.Minute /* finalizeTimeout */)

	ctx := context.Background()
	ts := zktopo.NewTestServer(t, []string{"cell1"})
	wr := wrangler.New(logutil.NewConsoleLogger(), ts, tmclient.NewTabletManagerClient(), time.Second)

	// Create an old master, a new master, two good slaves, one bad slave
	oldMaster := NewFakeTablet(t, wr, "cell1", 0, topo.TYPE_MASTER)
	newMaster := NewFakeTablet(t, wr, "cell1", 1, topo.TYPE_REPLICA)
	goodSlave := NewFakeTablet(t, wr, "cell1", 2, topo.TYPE_REPLICA)

	// On the elected master, we will respond to
	// TabletActionSlaveWasPromoted, so we need a MysqlDaemon
	// that returns no master, and the new port (as returned by mysql)
	newMaster.StartActionLoop(t, wr)
	defer newMaster.StopActionLoop(t)

	// On the old master, we will only respond to
	// TabletActionSlaveWasRestarted and point to a bad host
	oldMaster.StartActionLoop(t, wr)
	defer oldMaster.StopActionLoop(t)

	// On the good slave, we will respond to
	// TabletActionSlaveWasRestarted and point to a bad host
	goodSlave.StartActionLoop(t, wr)
	defer goodSlave.StopActionLoop(t)

	// This tests the good case, where everything works as planned
	t.Logf("TabletExternallyReparented(new master) expecting success")
	tmc := tmclient.NewTabletManagerClient()
	ti, err := ts.GetTablet(ctx, newMaster.Tablet.Alias)
	if err != nil {
		t.Fatalf("GetTablet failed: %v", err)
	}
	if err := tmc.TabletExternallyReparented(context.Background(), ti, ""); err != nil {
		t.Fatalf("TabletExternallyReparented(replica) failed: %v", err)
	}
}

func TestTabletExternallyReparented(t *testing.T) {
	tabletmanager.SetReparentFlags(time.Minute /* finalizeTimeout */)

	ctx := context.Background()
	db := fakesqldb.Register()
	ts := zktopo.NewTestServer(t, []string{"cell1", "cell2"})
	wr := wrangler.New(logutil.NewConsoleLogger(), ts, tmclient.NewTabletManagerClient(), time.Second)
	vp := NewVtctlPipe(t, ts)
	defer vp.Close()

	// Create an old master, a new master, two good slaves, one bad slave
	oldMaster := NewFakeTablet(t, wr, "cell1", 0, pb.TabletType_MASTER, db)
	newMaster := NewFakeTablet(t, wr, "cell1", 1, pb.TabletType_REPLICA, db)
	goodSlave1 := NewFakeTablet(t, wr, "cell1", 2, pb.TabletType_REPLICA, db)
	goodSlave2 := NewFakeTablet(t, wr, "cell2", 3, pb.TabletType_REPLICA, db)
	badSlave := NewFakeTablet(t, wr, "cell1", 4, pb.TabletType_REPLICA, db)

	// Add a new Cell to the Shard, that doesn't map to any read topo cell,
	// to simulate a data center being unreachable.
	si, err := ts.GetShard(ctx, "test_keyspace", "0")
	if err != nil {
		t.Fatalf("GetShard failed: %v", err)
	}
	si.Cells = append(si.Cells, "cell666")
	if err := ts.UpdateShard(ctx, si); err != nil {
		t.Fatalf("UpdateShard failed: %v", err)
	}

	// Slightly unrelated test: make sure we can find the tablets
	// even with a datacenter being down.
	tabletMap, err := ts.GetTabletMapForShardByCell(ctx, "test_keyspace", "0", []string{"cell1"})
	if err != nil {
		t.Fatalf("GetTabletMapForShardByCell should have worked but got: %v", err)
	}
	master, err := topotools.FindTabletByIPAddrAndPort(tabletMap, oldMaster.Tablet.Ip, "vt", oldMaster.Tablet.PortMap["vt"])
	if err != nil || !topoproto.TabletAliasEqual(&master, oldMaster.Tablet.Alias) {
		t.Fatalf("FindTabletByIPAddrAndPort(master) failed: %v %v", err, master)
	}
	slave1, err := topotools.FindTabletByIPAddrAndPort(tabletMap, goodSlave1.Tablet.Ip, "vt", goodSlave1.Tablet.PortMap["vt"])
	if err != nil || !topoproto.TabletAliasEqual(&slave1, goodSlave1.Tablet.Alias) {
		t.Fatalf("FindTabletByIPAddrAndPort(slave1) failed: %v %v", err, master)
	}
	slave2, err := topotools.FindTabletByIPAddrAndPort(tabletMap, goodSlave2.Tablet.Ip, "vt", goodSlave2.Tablet.PortMap["vt"])
	if err != topo.ErrNoNode {
		t.Fatalf("FindTabletByIPAddrAndPort(slave2) worked: %v %v", err, slave2)
	}

	// Make sure the master is not exported in other cells
	tabletMap, err = ts.GetTabletMapForShardByCell(ctx, "test_keyspace", "0", []string{"cell2"})
	master, err = topotools.FindTabletByIPAddrAndPort(tabletMap, oldMaster.Tablet.Ip, "vt", oldMaster.Tablet.PortMap["vt"])
	if err != topo.ErrNoNode {
		t.Fatalf("FindTabletByIPAddrAndPort(master) worked in cell2: %v %v", err, master)
	}

	tabletMap, err = ts.GetTabletMapForShard(ctx, "test_keyspace", "0")
	if err != topo.ErrPartialResult {
		t.Fatalf("GetTabletMapForShard should have returned ErrPartialResult but got: %v", err)
	}
	master, err = topotools.FindTabletByIPAddrAndPort(tabletMap, oldMaster.Tablet.Ip, "vt", oldMaster.Tablet.PortMap["vt"])
	if err != nil || !topoproto.TabletAliasEqual(&master, oldMaster.Tablet.Alias) {
		t.Fatalf("FindTabletByIPAddrAndPort(master) failed: %v %v", err, master)
	}

	// On the elected master, we will respond to
	// TabletActionSlaveWasPromoted
	newMaster.StartActionLoop(t, wr)
	defer newMaster.StopActionLoop(t)

	// On the old master, we will only respond to
	// TabletActionSlaveWasRestarted.
	oldMaster.StartActionLoop(t, wr)
	defer oldMaster.StopActionLoop(t)

	// On the good slaves, we will respond to
	// TabletActionSlaveWasRestarted.
	goodSlave1.StartActionLoop(t, wr)
	defer goodSlave1.StopActionLoop(t)

	goodSlave2.StartActionLoop(t, wr)
	defer goodSlave2.StopActionLoop(t)

	// On the bad slave, we will respond to
	// TabletActionSlaveWasRestarted with bad data.
	badSlave.StartActionLoop(t, wr)
	defer badSlave.StopActionLoop(t)

	// First test: reparent to the same master, make sure it works
	// as expected.
	tmc := tmclient.NewTabletManagerClient()
	ti, err := ts.GetTablet(ctx, oldMaster.Tablet.Alias)
	if err != nil {
		t.Fatalf("GetTablet failed: %v", err)
	}
	if err := vp.Run([]string{"TabletExternallyReparented", topoproto.TabletAliasString(oldMaster.Tablet.Alias)}); err != nil {
		t.Fatalf("TabletExternallyReparented(same master) should have worked: %v", err)
	}

	// Second test: reparent to a replica, and pretend the old
	// master is still good to go.

//.........这里部分代码省略.........