Golang topotools.RebuildShard函数代码示例

// rebuildShardIfNeeded will rebuild the serving graph if we need to
func (agent *ActionAgent) rebuildShardIfNeeded(tablet *topo.TabletInfo, targetTabletType topo.TabletType, lockTimeout time.Duration) error {
	if topo.IsInServingGraph(targetTabletType) {
		// TODO: interrupted may need to be a global one closed when we exit
		interrupted := make(chan struct{})

		if *topotools.UseSrvShardLocks {
			// no need to take the shard lock in this case
			if err := topotools.RebuildShard(agent.TopoServer, tablet.Keyspace, tablet.Shard, topotools.RebuildShardOptions{Cells: []string{tablet.Alias.Cell}, IgnorePartialResult: true}, lockTimeout, interrupted); err != nil {
				return fmt.Errorf("topotools.RebuildShard returned an error: %v", err)
			}
		} else {
			actionNode := actionnode.RebuildShard()
			lockPath, err := actionNode.LockShard(agent.TopoServer, tablet.Keyspace, tablet.Shard, lockTimeout, interrupted)
			if err != nil {
				return fmt.Errorf("cannot lock shard for rebuild: %v", err)
			}
			err = topotools.RebuildShard(agent.TopoServer, tablet.Keyspace, tablet.Shard, topotools.RebuildShardOptions{Cells: []string{tablet.Alias.Cell}, IgnorePartialResult: true}, lockTimeout, interrupted)
			err = actionNode.UnlockShard(agent.TopoServer, tablet.Keyspace, tablet.Shard, lockPath, err)
			if err != nil {
				return fmt.Errorf("UnlockShard returned an error: %v", err)
			}
		}
	}
	return nil
}

// Rebuild the serving and replication rollup data data while locking
// out other changes.
func (wr *Wrangler) RebuildShardGraph(keyspace, shard string, cells []string) error {
	if *topotools.UseSrvShardLocks {
		// no need to take the shard lock in this case
		return topotools.RebuildShard(wr.ts, keyspace, shard, topotools.RebuildShardOptions{Cells: cells, IgnorePartialResult: false}, wr.lockTimeout, interrupted)
	}

	actionNode := actionnode.RebuildShard()
	lockPath, err := wr.lockShard(keyspace, shard, actionNode)
	if err != nil {
		return err
	}

	err = topotools.RebuildShard(wr.ts, keyspace, shard, topotools.RebuildShardOptions{Cells: cells, IgnorePartialResult: false}, wr.lockTimeout, interrupted)
	return wr.unlockShard(keyspace, shard, actionNode, lockPath, err)
}

// same as ChangeType, but assume we already have the shard lock,
// and do not have the option to force anything.
func (wr *Wrangler) changeTypeInternal(tabletAlias topo.TabletAlias, dbType topo.TabletType) error {
	ti, err := wr.ts.GetTablet(tabletAlias)
	if err != nil {
		return err
	}
	rebuildRequired := ti.Tablet.IsInServingGraph()

	// change the type
	if wr.UseRPCs {
		if err := wr.ai.RpcChangeType(ti, dbType, wr.ActionTimeout()); err != nil {
			return err
		}
	} else {
		actionPath, err := wr.ai.ChangeType(ti.Alias, dbType)
		if err != nil {
			return err
		}
		err = wr.WaitForCompletion(actionPath)
		if err != nil {
			return err
		}
	}

	// rebuild if necessary
	if rebuildRequired {
		err = topotools.RebuildShard(wr.logger, wr.ts, ti.Keyspace, ti.Shard, []string{ti.Alias.Cell}, wr.lockTimeout, interrupted)
		if err != nil {
			return err
		}
	}
	return nil
}

func (wr *Wrangler) finishReparent(si *topo.ShardInfo, masterElect *topo.TabletInfo, majorityRestart, leaveMasterReadOnly bool) error {
	// If the majority of slaves restarted, move ahead.
	if majorityRestart {
		if leaveMasterReadOnly {
			log.Warningf("leaving master-elect read-only, change with: vtctl SetReadWrite %v", masterElect.Alias)
		} else {
			log.Infof("marking master-elect read-write %v", masterElect.Alias)
			actionPath, err := wr.ai.SetReadWrite(masterElect.Alias)
			if err == nil {
				err = wr.ai.WaitForCompletion(actionPath, wr.actionTimeout())
			}
			if err != nil {
				log.Warningf("master master-elect read-write failed, leaving master-elect read-only, change with: vtctl SetReadWrite %v", masterElect.Alias)
			}
		}
	} else {
		log.Warningf("minority reparent, manual fixes are needed, leaving master-elect read-only, change with: vtctl SetReadWrite %v", masterElect.Alias)
	}

	// save the new master in the shard info
	si.MasterAlias = masterElect.Alias
	if err := wr.ts.UpdateShard(si); err != nil {
		log.Errorf("Failed to save new master into shard: %v", err)
		return err
	}

	// We rebuild all the cells, as we may have taken tablets in and
	// out of the graph.
	log.Infof("rebuilding shard serving graph data")
	return topotools.RebuildShard(wr.ts, masterElect.Keyspace, masterElect.Shard, topotools.RebuildShardOptions{IgnorePartialResult: false}, wr.lockTimeout, interrupted)
}

func (wr *Wrangler) finishReparent(si *topo.ShardInfo, masterElect *topo.TabletInfo, majorityRestart, leaveMasterReadOnly bool) error {
	// If the majority of slaves restarted, move ahead.
	if majorityRestart {
		if leaveMasterReadOnly {
			wr.logger.Warningf("leaving master-elect read-only, change with: vtctl SetReadWrite %v", masterElect.Alias)
		} else {
			wr.logger.Infof("marking master-elect read-write %v", masterElect.Alias)
			if err := wr.tmc.SetReadWrite(masterElect, wr.ActionTimeout()); err != nil {
				wr.logger.Warningf("master master-elect read-write failed, leaving master-elect read-only, change with: vtctl SetReadWrite %v", masterElect.Alias)
			}
		}
	} else {
		wr.logger.Warningf("minority reparent, manual fixes are needed, leaving master-elect read-only, change with: vtctl SetReadWrite %v", masterElect.Alias)
	}

	// save the new master in the shard info
	si.MasterAlias = masterElect.Alias
	if err := topo.UpdateShard(wr.ts, si); err != nil {
		wr.logger.Errorf("Failed to save new master into shard: %v", err)
		return err
	}

	// We rebuild all the cells, as we may have taken tablets in and
	// out of the graph.
	wr.logger.Infof("rebuilding shard serving graph data")
	_, err := topotools.RebuildShard(wr.logger, wr.ts, masterElect.Keyspace, masterElect.Shard, nil, wr.lockTimeout, interrupted)
	return err
}

func (wr *Wrangler) shardExternallyReparentedLocked(keyspace, shard string, masterElectTabletAlias topo.TabletAlias) error {
	// read the shard, make sure the master is not already good.
	// critical read, we want up to date info (and the shard is locked).
	shardInfo, err := wr.ts.GetShardCritical(keyspace, shard)
	if err != nil {
		return err
	}
	if shardInfo.MasterAlias == masterElectTabletAlias {
		return fmt.Errorf("master-elect tablet %v is already master", masterElectTabletAlias)
	}

	// Read the tablets, make sure the master elect is known to us.
	// Note we will keep going with a partial tablet map, which usually
	// happens when a cell is not reachable. After these checks, the
	// guarantees we'll have are:
	// - global cell is reachable (we just locked and read the shard)
	// - the local cell that contains the new master is reachable
	//   (as we're going to check the new master is in the list)
	// That should be enough.
	tabletMap, err := topo.GetTabletMapForShard(wr.ts, keyspace, shard)
	switch err {
	case nil:
		// keep going
	case topo.ErrPartialResult:
		log.Warningf("Got topo.ErrPartialResult from GetTabletMapForShard, may need to re-init some tablets")
	default:
		return err
	}
	masterElectTablet, ok := tabletMap[masterElectTabletAlias]
	if !ok {
		return fmt.Errorf("master-elect tablet %v not found in replication graph %v/%v %v", masterElectTabletAlias, keyspace, shard, mapKeys(tabletMap))
	}

	// sort the tablets, and handle them
	slaveTabletMap, masterTabletMap := sortedTabletMap(tabletMap)
	err = wr.reparentShardExternal(slaveTabletMap, masterTabletMap, masterElectTablet)
	if err != nil {
		log.Infof("Skipping shard rebuild with failed reparent")
		return err
	}

	// Compute the list of Cells we need to rebuild: old master and
	// new master cells.
	cells := []string{shardInfo.MasterAlias.Cell}
	if shardInfo.MasterAlias.Cell != masterElectTabletAlias.Cell {
		cells = append(cells, masterElectTabletAlias.Cell)
	}

	// now update the master record in the shard object
	log.Infof("Updating Shard's MasterAlias record")
	shardInfo.MasterAlias = masterElectTabletAlias
	if err = wr.ts.UpdateShard(shardInfo); err != nil {
		return err
	}

	// and rebuild the shard serving graph
	log.Infof("Rebuilding shard serving graph data")
	return topotools.RebuildShard(wr.ts, masterElectTablet.Keyspace, masterElectTablet.Shard, cells, wr.lockTimeout, interrupted)
}

// rebuildShardIfNeeded will rebuild the serving graph if we need to
func (agent *ActionAgent) rebuildShardIfNeeded(tablet *topo.TabletInfo, targetTabletType topo.TabletType) error {
	if topo.IsInServingGraph(targetTabletType) {
		// TODO: interrupted may need to be a global one closed when we exit
		interrupted := make(chan struct{})

		// no need to take the shard lock in this case
		if err := topotools.RebuildShard(logutil.NewConsoleLogger(), agent.TopoServer, tablet.Keyspace, tablet.Shard, []string{tablet.Alias.Cell}, agent.LockTimeout, interrupted); err != nil {
			return fmt.Errorf("topotools.RebuildShard returned an error: %v", err)
		}
	}
	return nil
}

func tabletExternallyReparentedLocked(ts topo.Server, tablet *topo.TabletInfo, actionTimeout, lockTimeout time.Duration, interrupted chan struct{}) (err error) {
	// read the shard, make sure again the master is not already good.
	// critical read, we want up to date info (and the shard is locked).
	shardInfo, err := ts.GetShardCritical(tablet.Keyspace, tablet.Shard)
	if err != nil {
		return err
	}
	if shardInfo.MasterAlias == tablet.Alias {
		return fmt.Errorf("this tablet is already the master")
	}

	// Read the tablets, make sure the master elect is known to the shard
	// (it's this tablet, so it better be!).
	// Note we will keep going with a partial tablet map, which usually
	// happens when a cell is not reachable. After these checks, the
	// guarantees we'll have are:
	// - global cell is reachable (we just locked and read the shard)
	// - the local cell that contains the new master is reachable
	//   (as we're going to check the new master is in the list)
	// That should be enough.
	tabletMap, err := topo.GetTabletMapForShard(ts, tablet.Keyspace, tablet.Shard)
	switch err {
	case nil:
		// keep going
	case topo.ErrPartialResult:
		log.Warningf("Got topo.ErrPartialResult from GetTabletMapForShard, may need to re-init some tablets")
	default:
		return err
	}
	masterElectTablet, ok := tabletMap[tablet.Alias]
	if !ok {
		return fmt.Errorf("this master-elect tablet %v not found in replication graph %v/%v %v", tablet.Alias, tablet.Keyspace, tablet.Shard, topotools.MapKeys(tabletMap))
	}

	// Create reusable Reparent event with available info
	ev := &events.Reparent{
		ShardInfo: *shardInfo,
		NewMaster: *tablet.Tablet,
	}

	if oldMasterTablet, ok := tabletMap[shardInfo.MasterAlias]; ok {
		ev.OldMaster = *oldMasterTablet.Tablet
	}

	defer func() {
		if err != nil {
			event.DispatchUpdate(ev, "failed: "+err.Error())
		}
	}()

	// sort the tablets, and handle them
	slaveTabletMap, masterTabletMap := topotools.SortedTabletMap(tabletMap)
	event.DispatchUpdate(ev, "starting external from tablet")

	// we fix the new master in the replication graph
	event.DispatchUpdate(ev, "mark ourself as new master")
	err = updateReplicationGraphForPromotedSlave(ts, tablet)
	if err != nil {
		// This suggests we can't talk to topo server. This is bad.
		return fmt.Errorf("updateReplicationGraphForPromotedSlave failed: %v", err)
	}

	// Once this tablet is promoted, remove it from our maps
	delete(slaveTabletMap, tablet.Alias)
	delete(masterTabletMap, tablet.Alias)

	// Then fix all the slaves, including the old master.  This
	// last step is very likely to time out for some tablets (one
	// random guy is dead, the old master is dead, ...). We
	// execute them all in parallel until we get to
	// wr.ActionTimeout(). After this, no other action with a
	// timeout is executed, so even if we got to the timeout,
	// we're still good.
	event.DispatchUpdate(ev, "restarting slaves")
	logger := logutil.NewConsoleLogger()
	ai := initiator.NewActionInitiator(ts)
	topotools.RestartSlavesExternal(ts, logger, slaveTabletMap, masterTabletMap, masterElectTablet.Alias, func(ti *topo.TabletInfo, swrd *actionnode.SlaveWasRestartedArgs) error {
		return ai.RpcSlaveWasRestarted(ti, swrd, actionTimeout)
	})

	// Compute the list of Cells we need to rebuild: old master and
	// all other cells if reparenting to another cell.
	cells := []string{shardInfo.MasterAlias.Cell}
	if shardInfo.MasterAlias.Cell != tablet.Alias.Cell {
		cells = nil
	}

	// now update the master record in the shard object
	event.DispatchUpdate(ev, "updating shard record")
	log.Infof("Updating Shard's MasterAlias record")
	shardInfo.MasterAlias = tablet.Alias
	if err = topo.UpdateShard(ts, shardInfo); err != nil {
		return err
	}

	// and rebuild the shard serving graph
	event.DispatchUpdate(ev, "rebuilding shard serving graph")
	log.Infof("Rebuilding shard serving graph data")
	if err = topotools.RebuildShard(logger, ts, tablet.Keyspace, tablet.Shard, cells, lockTimeout, interrupted); err != nil {
		return err
//.........这里部分代码省略.........

// RunHealthCheck takes the action mutex, runs the health check,
// and if we need to change our state, do it.
// If we are the master, we don't change our type, healthy or not.
// If we are not the master, we change to spare if not healthy,
// or to the passed in targetTabletType if healthy.
//
// Note we only update the topo record if we need to, that is if our type or
// health details changed.
func (agent *ActionAgent) RunHealthCheck(targetTabletType topo.TabletType, lockTimeout time.Duration) {
	agent.actionMutex.Lock()
	defer agent.actionMutex.Unlock()

	// read the current tablet record
	agent.mutex.Lock()
	tablet := agent._tablet
	agent.mutex.Unlock()

	// run the health check
	typeForHealthCheck := targetTabletType
	if tablet.Type == topo.TYPE_MASTER {
		typeForHealthCheck = topo.TYPE_MASTER
	}
	health, err := health.Run(typeForHealthCheck)

	// start with no change
	newTabletType := tablet.Type
	if err != nil {
		if tablet.Type != targetTabletType {
			log.Infof("Tablet not healthy and in state %v, not changing it: %v", tablet.Type, err)
			return
		}
		log.Infof("Tablet not healthy, converting it from %v to spare: %v", targetTabletType, err)
		newTabletType = topo.TYPE_SPARE
	} else {
		// We are healthy, maybe with health, see if we need
		// to update the record. We only change from spare to
		// our target type.
		if tablet.Type == topo.TYPE_SPARE {
			newTabletType = targetTabletType
		}
		if tablet.Type == newTabletType && tablet.IsHealthEqual(health) {
			// no change in health, not logging anything,
			// and we're done
			return
		}

		// we need to update our state
		log.Infof("Updating tablet record as healthy type %v -> %v with health details %v -> %v", tablet.Type, newTabletType, tablet.Health, health)
	}

	// Change the Type, update the health. Note we pass in a map
	// that's not nil, meaning if it's empty, we will clear it.
	if err := topotools.ChangeType(agent.TopoServer, tablet.Alias, newTabletType, health, true /*runHooks*/); err != nil {
		log.Infof("Error updating tablet record: %v", err)
		return
	}

	// Rebuild the serving graph in our cell, only if we're dealing with
	// a serving type
	if topo.IsInServingGraph(targetTabletType) {
		// TODO: interrupted may need to be a global one closed when we exit
		interrupted := make(chan struct{})

		if *topotools.UseSrvShardLocks {
			// no need to take the shard lock in this case
			if err := topotools.RebuildShard(agent.TopoServer, tablet.Keyspace, tablet.Shard, topotools.RebuildShardOptions{Cells: []string{tablet.Alias.Cell}, IgnorePartialResult: true}, lockTimeout, interrupted); err != nil {
				log.Warningf("topotools.RebuildShard returned an error: %v", err)
				return
			}
		} else {
			actionNode := actionnode.RebuildShard()
			lockPath, err := actionNode.LockShard(agent.TopoServer, tablet.Keyspace, tablet.Shard, lockTimeout, interrupted)
			if err != nil {
				log.Warningf("Cannot lock shard for rebuild: %v", err)
				return
			}
			err = topotools.RebuildShard(agent.TopoServer, tablet.Keyspace, tablet.Shard, topotools.RebuildShardOptions{Cells: []string{tablet.Alias.Cell}, IgnorePartialResult: true}, lockTimeout, interrupted)
			err = actionNode.UnlockShard(agent.TopoServer, tablet.Keyspace, tablet.Shard, lockPath, err)
			if err != nil {
				log.Warningf("UnlockShard returned an error: %v", err)
				return
			}
		}
	}

	// run the post action callbacks
	agent.afterAction("healthcheck", false /* reloadSchema */)
}

func (wr *Wrangler) shardExternallyReparentedLocked(keyspace, shard string, masterElectTabletAlias topo.TabletAlias) (err error) {
	// read the shard, make sure the master is not already good.
	shardInfo, err := wr.ts.GetShard(keyspace, shard)
	if err != nil {
		return err
	}
	if shardInfo.MasterAlias == masterElectTabletAlias {
		return fmt.Errorf("master-elect tablet %v is already master", masterElectTabletAlias)
	}

	// Read the tablets, make sure the master elect is known to us.
	// Note we will keep going with a partial tablet map, which usually
	// happens when a cell is not reachable. After these checks, the
	// guarantees we'll have are:
	// - global cell is reachable (we just locked and read the shard)
	// - the local cell that contains the new master is reachable
	//   (as we're going to check the new master is in the list)
	// That should be enough.
	tabletMap, err := topo.GetTabletMapForShard(wr.ts, keyspace, shard)
	switch err {
	case nil:
		// keep going
	case topo.ErrPartialResult:
		wr.logger.Warningf("Got topo.ErrPartialResult from GetTabletMapForShard, may need to re-init some tablets")
	default:
		return err
	}
	masterElectTablet, ok := tabletMap[masterElectTabletAlias]
	if !ok {
		return fmt.Errorf("master-elect tablet %v not found in replication graph %v/%v %v", masterElectTabletAlias, keyspace, shard, topotools.MapKeys(tabletMap))
	}

	// Create reusable Reparent event with available info
	ev := &events.Reparent{
		ShardInfo: *shardInfo,
		NewMaster: *masterElectTablet.Tablet,
	}

	if oldMasterTablet, ok := tabletMap[shardInfo.MasterAlias]; ok {
		ev.OldMaster = *oldMasterTablet.Tablet
	}

	defer func() {
		if err != nil {
			event.DispatchUpdate(ev, "failed: "+err.Error())
		}
	}()

	// sort the tablets, and handle them
	slaveTabletMap, masterTabletMap := topotools.SortedTabletMap(tabletMap)
	err = wr.reparentShardExternal(ev, slaveTabletMap, masterTabletMap, masterElectTablet)
	if err != nil {
		wr.logger.Infof("Skipping shard rebuild with failed reparent")
		return err
	}

	// Compute the list of Cells we need to rebuild: old master and
	// all other cells if reparenting to another cell.
	cells := []string{shardInfo.MasterAlias.Cell}
	if shardInfo.MasterAlias.Cell != masterElectTabletAlias.Cell {
		cells = nil
	}

	// now update the master record in the shard object
	event.DispatchUpdate(ev, "updating shard record")
	wr.logger.Infof("Updating Shard's MasterAlias record")
	shardInfo.MasterAlias = masterElectTabletAlias
	if err = topo.UpdateShard(wr.ts, shardInfo); err != nil {
		return err
	}

	// and rebuild the shard serving graph
	event.DispatchUpdate(ev, "rebuilding shard serving graph")
	wr.logger.Infof("Rebuilding shard serving graph data")
	if _, err = topotools.RebuildShard(wr.logger, wr.ts, masterElectTablet.Keyspace, masterElectTablet.Shard, cells, wr.lockTimeout, interrupted); err != nil {
		return err
	}

	event.DispatchUpdate(ev, "finished")
	return nil
}

// Rebuild the serving and replication rollup data data while locking
// out other changes.
func (wr *Wrangler) RebuildShardGraph(keyspace, shard string, cells []string) error {
	return topotools.RebuildShard(wr.logger, wr.ts, keyspace, shard, cells, wr.lockTimeout, interrupted)
}

func TestAPI(t *testing.T) {
	ctx := context.Background()
	cells := []string{"cell1", "cell2"}
	ts := zktopo.NewTestServer(t, cells)
	actionRepo := NewActionRepository(ts)
	initAPI(ctx, ts, actionRepo)

	server := httptest.NewServer(nil)
	defer server.Close()

	// Populate topo.
	ts.CreateKeyspace(ctx, "ks1", &topodatapb.Keyspace{ShardingColumnName: "shardcol"})
	ts.Impl.CreateShard(ctx, "ks1", "-80", &topodatapb.Shard{
		Cells:    cells,
		KeyRange: &topodatapb.KeyRange{Start: nil, End: []byte{0x80}},
	})
	ts.Impl.CreateShard(ctx, "ks1", "80-", &topodatapb.Shard{
		Cells:    cells,
		KeyRange: &topodatapb.KeyRange{Start: []byte{0x80}, End: nil},
	})

	ts.CreateTablet(ctx, &topodatapb.Tablet{
		Alias:    &topodatapb.TabletAlias{Cell: "cell1", Uid: 100},
		Keyspace: "ks1",
		Shard:    "-80",
		Type:     topodatapb.TabletType_REPLICA,
		KeyRange: &topodatapb.KeyRange{Start: nil, End: []byte{0x80}},
		PortMap:  map[string]int32{"vt": 100},
	})
	ts.CreateTablet(ctx, &topodatapb.Tablet{
		Alias:    &topodatapb.TabletAlias{Cell: "cell2", Uid: 200},
		Keyspace: "ks1",
		Shard:    "-80",
		Type:     topodatapb.TabletType_REPLICA,
		KeyRange: &topodatapb.KeyRange{Start: nil, End: []byte{0x80}},
		PortMap:  map[string]int32{"vt": 200},
	})
	topotools.RebuildShard(ctx, logutil.NewConsoleLogger(), ts, "ks1", "-80", cells)

	// Populate fake actions.
	actionRepo.RegisterKeyspaceAction("TestKeyspaceAction",
		func(ctx context.Context, wr *wrangler.Wrangler, keyspace string, r *http.Request) (string, error) {
			return "TestKeyspaceAction Result", nil
		})
	actionRepo.RegisterShardAction("TestShardAction",
		func(ctx context.Context, wr *wrangler.Wrangler, keyspace, shard string, r *http.Request) (string, error) {
			return "TestShardAction Result", nil
		})
	actionRepo.RegisterTabletAction("TestTabletAction", "",
		func(ctx context.Context, wr *wrangler.Wrangler, tabletAlias *topodatapb.TabletAlias, r *http.Request) (string, error) {
			return "TestTabletAction Result", nil
		})

	// Test cases.
	table := []struct {
		method, path, want string
	}{
		// Cells
		{"GET", "cells", `["cell1","cell2"]`},

		// Keyspaces
		{"GET", "keyspaces", `["ks1"]`},
		{"GET", "keyspaces/ks1", `{
				"sharding_column_name": "shardcol"
			}`},
		{"POST", "keyspaces/ks1?action=TestKeyspaceAction", `{
				"Name": "TestKeyspaceAction",
				"Parameters": "ks1",
				"Output": "TestKeyspaceAction Result",
				"Error": false
			}`},

		// Shards
		{"GET", "shards/ks1/", `["-80","80-"]`},
		{"GET", "shards/ks1/-80", `{
				"key_range": {"end":"gA=="},
				"cells": ["cell1", "cell2"]
			}`},
		{"POST", "shards/ks1/-80?action=TestShardAction", `{
				"Name": "TestShardAction",
				"Parameters": "ks1/-80",
				"Output": "TestShardAction Result",
				"Error": false
			}`},

		// Tablets
		{"GET", "tablets/?shard=ks1%2F-80", `[
				{"cell":"cell1","uid":100},
				{"cell":"cell2","uid":200}
			]`},
		{"GET", "tablets/?cell=cell1", `[
				{"cell":"cell1","uid":100}
			]`},
		{"GET", "tablets/?shard=ks1%2F-80&cell=cell2", `[
				{"cell":"cell2","uid":200}
			]`},
		{"GET", "tablets/cell1-100", `{
				"alias": {"cell": "cell1", "uid": 100},
				"port_map": {"vt": 100},
				"keyspace": "ks1",
//.........这里部分代码省略.........

// RebuildShardGraph rebuilds the serving and replication rollup data data while locking
// out other changes.
func (wr *Wrangler) RebuildShardGraph(ctx context.Context, keyspace, shard string, cells []string) (*topo.ShardInfo, error) {
	return topotools.RebuildShard(ctx, wr.logger, wr.ts, keyspace, shard, cells, wr.lockTimeout)
}