Golang Server.GetTablet方法代码示例

// NewQueryResultReaderForTablet creates a new QueryResultReader for
// the provided tablet / sql query
func NewQueryResultReaderForTablet(ctx context.Context, ts topo.Server, tabletAlias topo.TabletAlias, sql string) (*QueryResultReader, error) {
	tablet, err := ts.GetTablet(ctx, tabletAlias)
	if err != nil {
		return nil, err
	}

	endPoint, err := tablet.EndPoint()
	if err != nil {
		return nil, err
	}

	conn, err := tabletconn.GetDialer()(ctx, *endPoint, tablet.Keyspace, tablet.Shard, *remoteActionsTimeout)
	if err != nil {
		return nil, err
	}

	sr, clientErrFn, err := conn.StreamExecute(ctx, sql, make(map[string]interface{}), 0)
	if err != nil {
		return nil, err
	}

	// read the columns, or grab the error
	cols, ok := <-sr
	if !ok {
		return nil, fmt.Errorf("Cannot read Fields for query '%v': %v", sql, clientErrFn())
	}

	return &QueryResultReader{
		Output:      sr,
		Fields:      cols.Fields,
		conn:        conn,
		clientErrFn: clientErrFn,
	}, nil
}

// If error is not nil, the results in the dictionary are incomplete.
func GetTabletMap(ts topo.Server, tabletAliases []topo.TabletAlias) (map[topo.TabletAlias]*topo.TabletInfo, error) {
	wg := sync.WaitGroup{}
	mutex := sync.Mutex{}

	tabletMap := make(map[topo.TabletAlias]*topo.TabletInfo)
	var someError error

	for _, tabletAlias := range tabletAliases {
		wg.Add(1)
		go func(tabletAlias topo.TabletAlias) {
			defer wg.Done()
			tabletInfo, err := ts.GetTablet(tabletAlias)
			mutex.Lock()
			if err != nil {
				relog.Warning("%v: %v", tabletAlias, err)
				// There can be data races removing nodes - ignore them for now.
				if err != topo.ErrNoNode {
					someError = err
				}
			} else {
				tabletMap[tabletAlias] = tabletInfo
			}
			mutex.Unlock()
		}(tabletAlias)
	}
	wg.Wait()
	return tabletMap, someError
}

// NewQueryResultReaderForTablet creates a new QueryResultReader for
// the provided tablet / sql query
func NewQueryResultReaderForTablet(ctx context.Context, ts topo.Server, tabletAlias *topodatapb.TabletAlias, sql string) (*QueryResultReader, error) {
	shortCtx, cancel := context.WithTimeout(ctx, *remoteActionsTimeout)
	tablet, err := ts.GetTablet(shortCtx, tabletAlias)
	cancel()
	if err != nil {
		return nil, err
	}

	conn, err := tabletconn.GetDialer()(tablet.Tablet, *remoteActionsTimeout)
	if err != nil {
		return nil, err
	}

	stream, err := conn.StreamExecute(ctx, &querypb.Target{
		Keyspace:   tablet.Tablet.Keyspace,
		Shard:      tablet.Tablet.Shard,
		TabletType: tablet.Tablet.Type,
	}, sql, make(map[string]interface{}), nil)
	if err != nil {
		return nil, err
	}

	// read the columns, or grab the error
	cols, err := stream.Recv()
	if err != nil {
		return nil, fmt.Errorf("Cannot read Fields for query '%v': %v", sql, err)
	}

	return &QueryResultReader{
		output: stream,
		fields: cols.Fields,
		conn:   conn,
	}, nil
}

// TabletExternallyReparented updates all topo records so the current
// tablet is the new master for this shard. It is called by the RPC
// server.
func TabletExternallyReparented(ts topo.Server, tabletAlias topo.TabletAlias, actionTimeout, lockTimeout time.Duration) error {
	// we're apprently not the master yet, so let's do the work
	tablet, err := ts.GetTablet(tabletAlias)
	if err != nil {
		return err
	}

	// fast quick check on the shard
	shardInfo, err := ts.GetShard(tablet.Keyspace, tablet.Shard)
	if err != nil {
		return err
	}
	if shardInfo.MasterAlias == tabletAlias {
		return nil
	}

	// grab the shard lock
	actionNode := actionnode.ShardExternallyReparented(tabletAlias)
	interrupted := make(chan struct{})
	lockPath, err := actionNode.LockShard(ts, tablet.Keyspace, tablet.Shard, lockTimeout, interrupted)
	if err != nil {
		return err
	}

	// do the work
	err = tabletExternallyReparentedLocked(ts, tablet, actionTimeout, lockTimeout, interrupted)

	// release the lock in any case
	return actionNode.UnlockShard(ts, tablet.Keyspace, tablet.Shard, lockPath, err)
}

func SlaveWasRestarted(ts topo.Server, tabletAlias topo.TabletAlias, swrd *actionnode.SlaveWasRestartedArgs) error {
	tablet, err := ts.GetTablet(tabletAlias)
	if err != nil {
		return err
	}

	// Once this action completes, update authoritive tablet node first.
	tablet.Parent = swrd.Parent
	if tablet.Type == topo.TYPE_MASTER {
		tablet.Type = topo.TYPE_SPARE
		tablet.State = topo.STATE_READ_ONLY
	}
	err = topo.UpdateTablet(ts, tablet)
	if err != nil {
		return err
	}

	// Update the new tablet location in the replication graph now that
	// we've updated the tablet.
	err = topo.CreateTabletReplicationData(ts, tablet.Tablet)
	if err != nil && err != topo.ErrNodeExists {
		return err
	}

	return nil
}

// CopyTablets will create the tablets in the destination topo
func CopyTablets(fromTS, toTS topo.Server) {
	cells, err := fromTS.GetKnownCells()
	if err != nil {
		log.Fatalf("fromTS.GetKnownCells failed: %v", err)
	}

	wg := sync.WaitGroup{}
	rec := concurrency.AllErrorRecorder{}
	for _, cell := range cells {
		wg.Add(1)
		go func(cell string) {
			defer wg.Done()
			tabletAliases, err := fromTS.GetTabletsByCell(cell)
			if err != nil {
				rec.RecordError(err)
			} else {
				for _, tabletAlias := range tabletAliases {
					wg.Add(1)
					go func(tabletAlias topo.TabletAlias) {
						defer wg.Done()

						// read the source tablet
						ti, err := fromTS.GetTablet(tabletAlias)
						if err != nil {
							rec.RecordError(err)
							return
						}

						// try to create the destination
						err = toTS.CreateTablet(ti.Tablet)
						if err == topo.ErrNodeExists {
							// update the destination tablet
							log.Warningf("tablet %v already exists, updating it", tabletAlias)
							err = toTS.UpdateTabletFields(ti.Alias(), func(t *topo.Tablet) error {
								*t = *ti.Tablet
								return nil
							})
						}
						if err != nil {
							rec.RecordError(err)
							return
						}

						// create the replication paths
						// for masters only here
						if ti.Type == topo.TYPE_MASTER {
							if err = toTS.CreateReplicationPath(ti.Keyspace, ti.Shard, ti.Alias().String()); err != nil && err != topo.ErrNodeExists {
								rec.RecordError(err)
							}
						}
					}(tabletAlias)
				}
			}
		}(cell)
	}
	wg.Wait()
	if rec.HasErrors() {
		log.Fatalf("copyTablets failed: %v", rec.Error())
	}
}

// NewRestartableResultReader creates a new RestartableResultReader for
// the provided tablet and chunk.
// It will automatically create the necessary query to read all rows within
// the chunk.
// NOTE: We assume that the Columns field in "td" was ordered by a preceding
// call to reorderColumnsPrimaryKeyFirst().
func NewRestartableResultReader(ctx context.Context, logger logutil.Logger, ts topo.Server, tabletAlias *topodatapb.TabletAlias, td *tabletmanagerdatapb.TableDefinition, chunk chunk) (*RestartableResultReader, error) {
	shortCtx, cancel := context.WithTimeout(ctx, *remoteActionsTimeout)
	tablet, err := ts.GetTablet(shortCtx, tabletAlias)
	cancel()
	if err != nil {
		return nil, fmt.Errorf("tablet=%v table=%v chunk=%v: Failed to resolve tablet alias: %v", topoproto.TabletAliasString(tabletAlias), td.Name, chunk, err)
	}

	conn, err := tabletconn.GetDialer()(tablet.Tablet, *remoteActionsTimeout)
	if err != nil {
		return nil, fmt.Errorf("tablet=%v table=%v chunk=%v: Failed to get dialer for tablet: %v", topoproto.TabletAliasString(tabletAlias), td.Name, chunk, err)
	}

	r := &RestartableResultReader{
		ctx:    ctx,
		logger: logger,
		tablet: tablet.Tablet,
		td:     td,
		chunk:  chunk,
		conn:   conn,
	}

	if err := r.startStream(); err != nil {
		return nil, err
	}
	logger.Infof("tablet=%v table=%v chunk=%v: Starting to stream rows using query '%v'.", topoproto.TabletAliasString(tabletAlias), td.Name, chunk, r.query)
	return r, nil
}

// ChangeType changes the type of the tablet and possibly also updates
// the health informaton for it. Make this external, since these
// transitions need to be forced from time to time.
//
// - if health is nil, we don't touch the Tablet's Health record.
// - if health is an empty map, we clear the Tablet's Health record.
// - if health has values, we overwrite the Tablet's Health record.
func ChangeType(ctx context.Context, ts topo.Server, tabletAlias topo.TabletAlias, newType topo.TabletType, health map[string]string) error {
	tablet, err := ts.GetTablet(ctx, tabletAlias)
	if err != nil {
		return err
	}

	if !topo.IsTrivialTypeChange(tablet.Type, newType) {
		return fmt.Errorf("cannot change tablet type %v -> %v %v", tablet.Type, newType, tabletAlias)
	}

	tablet.Type = newType
	if newType == topo.TYPE_IDLE {
		tablet.Keyspace = ""
		tablet.Shard = ""
		tablet.KeyRange = key.KeyRange{}
		tablet.Health = health
	}
	if health != nil {
		if len(health) == 0 {
			tablet.Health = nil
		} else {
			tablet.Health = health
		}
	}
	return topo.UpdateTablet(ctx, ts, tablet)
}

func SlaveWasPromoted(ts topo.Server, tabletAlias topo.TabletAlias) error {
	tablet, err := ts.GetTablet(tabletAlias)
	if err != nil {
		return err
	}

	return updateReplicationGraphForPromotedSlave(ts, tablet)
}

// Make this external, since these transitions need to be forced from time to time.
func SetBlacklistedTables(ts topo.Server, tabletAlias topo.TabletAlias, tables []string) error {
	tablet, err := ts.GetTablet(tabletAlias)
	if err != nil {
		return err
	}

	tablet.BlacklistedTables = tables
	return topo.UpdateTablet(ts, tablet)
}

// Make this external, since these transitions need to be forced from time to time.
func ChangeType(ts topo.Server, tabletAlias topo.TabletAlias, newType topo.TabletType, runHooks bool) error {
	tablet, err := ts.GetTablet(tabletAlias)
	if err != nil {
		return err
	}

	if !topo.IsTrivialTypeChange(tablet.Type, newType) || !topo.IsValidTypeChange(tablet.Type, newType) {
		return fmt.Errorf("cannot change tablet type %v -> %v %v", tablet.Type, newType, tabletAlias)
	}

	if runHooks {
		// Only run the preflight_serving_type hook when
		// transitioning from non-serving to serving.
		if !topo.IsInServingGraph(tablet.Type) && topo.IsInServingGraph(newType) {
			if err := hook.NewSimpleHook("preflight_serving_type").ExecuteOptional(); err != nil {
				return err
			}
		}
	}

	tablet.Type = newType
	if newType == topo.TYPE_IDLE {
		if tablet.Parent.IsZero() {
			si, err := ts.GetShard(tablet.Keyspace, tablet.Shard)
			if err != nil {
				return err
			}
			rec := concurrency.AllErrorRecorder{}
			wg := sync.WaitGroup{}
			for _, cell := range si.Cells {
				wg.Add(1)
				go func(cell string) {
					defer wg.Done()
					sri, err := ts.GetShardReplication(cell, tablet.Keyspace, tablet.Shard)
					if err != nil {
						log.Warningf("Cannot check cell %v for extra replication paths, assuming it's good", cell)
						return
					}
					for _, rl := range sri.ReplicationLinks {
						if rl.Parent == tabletAlias {
							rec.RecordError(fmt.Errorf("Still have a ReplicationLink in cell %v", cell))
						}
					}
				}(cell)
			}
			wg.Wait()
			if rec.HasErrors() {
				return rec.Error()
			}
		}
		tablet.Parent = topo.TabletAlias{}
		tablet.Keyspace = ""
		tablet.Shard = ""
		tablet.KeyRange = key.KeyRange{}
	}
	return topo.UpdateTablet(ts, tablet)
}

func (th *tabletHealth) stream(ctx context.Context, ts topo.Server, tabletAlias *topodatapb.TabletAlias) (err error) {
	defer func() {
		th.mu.Lock()
		th.err = err
		th.mu.Unlock()
		close(th.done)
	}()

	ti, err := ts.GetTablet(ctx, tabletAlias)
	if err != nil {
		return err
	}
	ep, err := topo.TabletEndPoint(ti.Tablet)
	if err != nil {
		return err
	}

	// Pass in a tablet type that is not UNKNOWN, so we don't ask
	// for sessionId.
	conn, err := tabletconn.GetDialer()(ctx, ep, "", "", topodatapb.TabletType_MASTER, 30*time.Second)
	if err != nil {
		return err
	}
	defer conn.Close()

	stream, err := conn.StreamHealth(ctx)
	if err != nil {
		return err
	}

	first := true
	for time.Since(th.lastAccessed()) < *tabletHealthKeepAlive {
		select {
		case <-ctx.Done():
			return ctx.Err()
		default:
		}

		result, err := stream.Recv()
		if err != nil {
			return err
		}

		th.mu.Lock()
		th.result = result
		th.mu.Unlock()

		if first {
			// We got the first result, so we're ready to be accessed.
			close(th.ready)
			first = false
		}
	}

	return nil
}

// handleExplorerRedirect returns the redirect target URL.
func handleExplorerRedirect(ctx context.Context, ts topo.Server, r *http.Request) (string, error) {
	keyspace := r.FormValue("keyspace")
	shard := r.FormValue("shard")
	cell := r.FormValue("cell")

	switch r.FormValue("type") {
	case "keyspace":
		if keyspace == "" {
			return "", errors.New("keyspace is required for this redirect")
		}
		return appPrefix + "#/keyspaces/", nil
	case "shard":
		if keyspace == "" || shard == "" {
			return "", errors.New("keyspace and shard are required for this redirect")
		}
		return appPrefix + fmt.Sprintf("#/shard/%s/%s", keyspace, shard), nil
	case "srv_keyspace":
		if keyspace == "" || cell == "" {
			return "", errors.New("keyspace and cell are required for this redirect")
		}
		return appPrefix + "#/keyspaces/", nil
	case "srv_shard":
		if keyspace == "" || shard == "" || cell == "" {
			return "", errors.New("keyspace, shard, and cell are required for this redirect")
		}
		return appPrefix + fmt.Sprintf("#/shard/%s/%s", keyspace, shard), nil
	case "srv_type":
		tabletType := r.FormValue("tablet_type")
		if keyspace == "" || shard == "" || cell == "" || tabletType == "" {
			return "", errors.New("keyspace, shard, cell, and tablet_type are required for this redirect")
		}
		return appPrefix + fmt.Sprintf("#/shard/%s/%s", keyspace, shard), nil
	case "tablet":
		alias := r.FormValue("alias")
		if alias == "" {
			return "", errors.New("alias is required for this redirect")
		}
		tabletAlias, err := topoproto.ParseTabletAlias(alias)
		if err != nil {
			return "", fmt.Errorf("bad tablet alias %q: %v", alias, err)
		}
		ti, err := ts.GetTablet(ctx, tabletAlias)
		if err != nil {
			return "", fmt.Errorf("can't get tablet %q: %v", alias, err)
		}
		return appPrefix + fmt.Sprintf("#/shard/%s/%s", ti.Keyspace, ti.Shard), nil
	case "replication":
		if keyspace == "" || shard == "" || cell == "" {
			return "", errors.New("keyspace, shard, and cell are required for this redirect")
		}
		return appPrefix + fmt.Sprintf("#/shard/%s/%s", keyspace, shard), nil
	default:
		return "", errors.New("bad redirect type")
	}
}

// Scrap will update the tablet type to 'Scrap', and remove it from
// the serving graph.
//
// 'force' means we are not on the tablet being scrapped, so it is
// probably dead. So if 'force' is true, we will also remove pending
// remote actions.  And if 'force' is false, we also run an optional
// hook.
func Scrap(ts topo.Server, tabletAlias topo.TabletAlias, force bool) error {
	tablet, err := ts.GetTablet(tabletAlias)
	if err != nil {
		return err
	}

	// If you are already scrap, skip updating replication data. It won't
	// be there anyway.
	wasAssigned := tablet.IsAssigned()
	tablet.Type = topo.TYPE_SCRAP
	tablet.Parent = topo.TabletAlias{}
	// Update the tablet first, since that is canonical.
	err = topo.UpdateTablet(ts, tablet)
	if err != nil {
		return err
	}

	// Remove any pending actions. Presumably forcing a scrap
	// means you don't want the agent doing anything and the
	// machine requires manual attention.
	if force {
		err := ts.PurgeTabletActions(tabletAlias, actionnode.ActionNodeCanBePurged)
		if err != nil {
			log.Warningf("purge actions failed: %v", err)
		}
	}

	if wasAssigned {
		err = topo.DeleteTabletReplicationData(ts, tablet.Tablet)
		if err != nil {
			if err == topo.ErrNoNode {
				log.V(6).Infof("no ShardReplication object for cell %v", tablet.Alias.Cell)
				err = nil
			}
			if err != nil {
				log.Warningf("remove replication data for %v failed: %v", tablet.Alias, err)
			}
		}
	}

	// run a hook for final cleanup, only in non-force mode.
	// (force mode executes on the vtctl side, not on the vttablet side)
	if !force {
		hk := hook.NewSimpleHook("postflight_scrap")
		ConfigureTabletHook(hk, tablet.Alias)
		if hookErr := hk.ExecuteOptional(); hookErr != nil {
			// we don't want to return an error, the server
			// is already in bad shape probably.
			log.Warningf("Scrap: postflight_scrap failed: %v", hookErr)
		}
	}

	return nil
}

func (th *tabletHealth) stream(ctx context.Context, ts topo.Server, tabletAlias topo.TabletAlias) (err error) {
	defer func() {
		th.mu.Lock()
		th.err = err
		th.mu.Unlock()
		close(th.done)
	}()

	ti, err := ts.GetTablet(ctx, tabletAlias)
	if err != nil {
		return err
	}
	ep, err := ti.EndPoint()
	if err != nil {
		return err
	}

	// pass in empty keyspace and shard to not ask for sessionId
	conn, err := tabletconn.GetDialer()(ctx, *ep, "", "", 30*time.Second)
	if err != nil {
		return err
	}
	defer conn.Close()

	stream, errFunc, err := conn.StreamHealth(ctx)
	if err != nil {
		return err
	}

	first := true
	for time.Since(th.lastAccessed()) < *tabletHealthKeepAlive {
		select {
		case <-ctx.Done():
			return ctx.Err()
		case result, ok := <-stream:
			if !ok {
				return errFunc()
			}

			th.mu.Lock()
			th.result = result
			th.mu.Unlock()

			if first {
				// We got the first result, so we're ready to be accessed.
				close(th.ready)
				first = false
			}
		}
	}

	return nil
}