Golang Server.GetShardReplication方法代码示例

// 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)
}

// CopyShardReplications will create the ShardReplication objects in
// the destination topo
func CopyShardReplications(ctx context.Context, fromTS, toTS topo.Server) {
	keyspaces, err := fromTS.GetKeyspaces(ctx)
	if err != nil {
		log.Fatalf("fromTS.GetKeyspaces: %v", err)
	}

	wg := sync.WaitGroup{}
	rec := concurrency.AllErrorRecorder{}
	for _, keyspace := range keyspaces {
		wg.Add(1)
		go func(keyspace string) {
			defer wg.Done()
			shards, err := fromTS.GetShardNames(ctx, keyspace)
			if err != nil {
				rec.RecordError(fmt.Errorf("GetShardNames(%v): %v", keyspace, err))
				return
			}

			for _, shard := range shards {
				wg.Add(1)
				go func(keyspace, shard string) {
					defer wg.Done()

					// read the source shard to get the cells
					si, err := fromTS.GetShard(ctx, keyspace, shard)
					if err != nil {
						rec.RecordError(fmt.Errorf("GetShard(%v, %v): %v", keyspace, shard, err))
						return
					}

					for _, cell := range si.Cells {
						sri, err := fromTS.GetShardReplication(ctx, cell, keyspace, shard)
						if err != nil {
							rec.RecordError(fmt.Errorf("GetShardReplication(%v, %v, %v): %v", cell, keyspace, shard, err))
							continue
						}

						if err := toTS.UpdateShardReplicationFields(ctx, cell, keyspace, shard, func(oldSR *pb.ShardReplication) error {
							*oldSR = *sri.ShardReplication
							return nil
						}); err != nil {
							rec.RecordError(fmt.Errorf("UpdateShardReplicationFields(%v, %v, %v): %v", cell, keyspace, shard, err))
						}
					}
				}(keyspace, shard)
			}
		}(keyspace)
	}
	wg.Wait()
	if rec.HasErrors() {
		log.Fatalf("copyShards failed: %v", rec.Error())
	}
}

func newCellShardTabletsCache(ts topo.Server) *VersionedObjectCacheMap {
	return NewVersionedObjectCacheMap(func(key string) *VersionedObjectCache {
		return NewVersionedObjectCache(func(ctx context.Context) (VersionedObject, error) {
			parts := strings.Split(key, "/")
			if len(parts) != 3 {
				return nil, fmt.Errorf("Invalid shard tablets path: %v", key)
			}
			sr, err := ts.GetShardReplication(ctx, parts[0], parts[1], parts[2])
			if err != nil {
				return nil, err
			}
			result := &CellShardTablets{
				Cell:          parts[0],
				KeyspaceName:  parts[1],
				ShardName:     parts[2],
				TabletAliases: make([]*topodatapb.TabletAlias, len(sr.Nodes)),
			}
			for i, node := range sr.Nodes {
				result.TabletAliases[i] = node.TabletAlias
			}
			return result, nil
		})
	})
}

// CopyShardReplications will create the ShardReplication objects in
// the destination topo
func CopyShardReplications(fromTS, toTS topo.Server) {
	keyspaces, err := fromTS.GetKeyspaces()
	if err != nil {
		log.Fatalf("fromTS.GetKeyspaces failed: %v", err)
	}

	wg := sync.WaitGroup{}
	rec := concurrency.AllErrorRecorder{}
	for _, keyspace := range keyspaces {
		wg.Add(1)
		go func(keyspace string) {
			defer wg.Done()
			shards, err := fromTS.GetShardNames(keyspace)
			if err != nil {
				rec.RecordError(err)
				return
			}

			for _, shard := range shards {
				wg.Add(1)
				go func(keyspace, shard string) {
					defer wg.Done()

					// read the source shard to get the cells
					si, err := fromTS.GetShard(keyspace, shard)
					if err != nil {
						rec.RecordError(err)
						return
					}

					for _, cell := range si.Cells {
						sri, err := fromTS.GetShardReplication(cell, keyspace, shard)
						if err != nil {
							rec.RecordError(err)
							continue
						}

						err = toTS.CreateShardReplication(cell, keyspace, shard, sri.ShardReplication)
						switch err {
						case nil:
							// good
						case topo.ErrNodeExists:
							if err := toTS.UpdateShardReplicationFields(cell, keyspace, shard, func(oldSR *topo.ShardReplication) error {
								*oldSR = *sri.ShardReplication
								return nil
							}); err != nil {
								rec.RecordError(err)
							}
						default:
							rec.RecordError(err)
						}
					}
				}(keyspace, shard)
			}
		}(keyspace)
	}
	wg.Wait()
	if rec.HasErrors() {
		log.Fatalf("copyShards failed: %v", rec.Error())
	}
}

// CheckShardReplication tests ShardReplication objects
func CheckShardReplication(ctx context.Context, t *testing.T, ts topo.Server) {
	cell := getLocalCell(ctx, t, ts)
	if _, err := ts.GetShardReplication(ctx, cell, "test_keyspace", "-10"); err != topo.ErrNoNode {
		t.Errorf("GetShardReplication(not there): %v", err)
	}

	sr := &topo.ShardReplication{
		ReplicationLinks: []topo.ReplicationLink{
			topo.ReplicationLink{
				TabletAlias: topo.TabletAlias{
					Cell: "c1",
					Uid:  1,
				},
			},
		},
	}
	if err := ts.UpdateShardReplicationFields(ctx, cell, "test_keyspace", "-10", func(oldSr *topo.ShardReplication) error {
		*oldSr = *sr
		return nil
	}); err != nil {
		t.Fatalf("UpdateShardReplicationFields() failed: %v", err)
	}

	if sri, err := ts.GetShardReplication(ctx, cell, "test_keyspace", "-10"); err != nil {
		t.Errorf("GetShardReplication(new guy) failed: %v", err)
	} else {
		if len(sri.ReplicationLinks) != 1 ||
			sri.ReplicationLinks[0].TabletAlias.Cell != "c1" ||
			sri.ReplicationLinks[0].TabletAlias.Uid != 1 {
			t.Errorf("GetShardReplication(new guy) returned wrong value: %v", *sri)
		}
	}

	if err := ts.UpdateShardReplicationFields(ctx, cell, "test_keyspace", "-10", func(sr *topo.ShardReplication) error {
		sr.ReplicationLinks = append(sr.ReplicationLinks, topo.ReplicationLink{
			TabletAlias: topo.TabletAlias{
				Cell: "c3",
				Uid:  3,
			},
		})
		return nil
	}); err != nil {
		t.Errorf("UpdateShardReplicationFields() failed: %v", err)
	}

	if sri, err := ts.GetShardReplication(ctx, cell, "test_keyspace", "-10"); err != nil {
		t.Errorf("GetShardReplication(after append) failed: %v", err)
	} else {
		if len(sri.ReplicationLinks) != 2 ||
			sri.ReplicationLinks[0].TabletAlias.Cell != "c1" ||
			sri.ReplicationLinks[0].TabletAlias.Uid != 1 ||
			sri.ReplicationLinks[1].TabletAlias.Cell != "c3" ||
			sri.ReplicationLinks[1].TabletAlias.Uid != 3 {
			t.Errorf("GetShardReplication(new guy) returned wrong value: %v", *sri)
		}
	}

	if err := ts.DeleteShardReplication(ctx, cell, "test_keyspace", "-10"); err != nil {
		t.Errorf("DeleteShardReplication(existing) failed: %v", err)
	}
	if err := ts.DeleteShardReplication(ctx, cell, "test_keyspace", "-10"); err != topo.ErrNoNode {
		t.Errorf("DeleteShardReplication(again) returned: %v", err)
	}
}

// Update shard file with new master, replicas, etc.
//
// Re-read from TopologyServer to make sure we are using the side
// effects of all actions.
//
// This function locks individual SvrShard paths, so it doesn't need a lock
// on the shard.
func RebuildShard(log logutil.Logger, ts topo.Server, keyspace, shard string, cells []string, timeout time.Duration, interrupted chan struct{}) error {
	log.Infof("RebuildShard %v/%v", keyspace, shard)

	// read the existing shard info. It has to exist.
	shardInfo, err := ts.GetShard(keyspace, shard)
	if err != nil {
		return err
	}

	// rebuild all cells in parallel
	wg := sync.WaitGroup{}
	rec := concurrency.AllErrorRecorder{}
	for _, cell := range shardInfo.Cells {
		// skip this cell if we shouldn't rebuild it
		if !topo.InCellList(cell, cells) {
			continue
		}

		// start with the master if it's in the current cell
		tabletsAsMap := make(map[topo.TabletAlias]bool)
		if shardInfo.MasterAlias.Cell == cell {
			tabletsAsMap[shardInfo.MasterAlias] = true
		}

		wg.Add(1)
		go func(cell string) {
			defer wg.Done()

			// read the ShardReplication object to find tablets
			sri, err := ts.GetShardReplication(cell, keyspace, shard)
			if err != nil {
				rec.RecordError(fmt.Errorf("GetShardReplication(%v, %v, %v) failed: %v", cell, keyspace, shard, err))
				return
			}

			// add all relevant tablets to the map
			for _, rl := range sri.ReplicationLinks {
				tabletsAsMap[rl.TabletAlias] = true
				if rl.Parent.Cell == cell {
					tabletsAsMap[rl.Parent] = true
				}
			}

			// convert the map to a list
			aliases := make([]topo.TabletAlias, 0, len(tabletsAsMap))
			for a := range tabletsAsMap {
				aliases = append(aliases, a)
			}

			// read all the Tablet records
			tablets, err := topo.GetTabletMap(ts, aliases)
			switch err {
			case nil:
				// keep going, we're good
			case topo.ErrPartialResult:
				log.Warningf("Got ErrPartialResult from topo.GetTabletMap in cell %v, some tablets may not be added properly to serving graph", cell)
			default:
				rec.RecordError(fmt.Errorf("GetTabletMap in cell %v failed: %v", cell, err))
				return
			}

			// Lock the SrvShard so we write a consistent data set.
			actionNode := actionnode.RebuildSrvShard()
			lockPath, err := actionNode.LockSrvShard(ts, cell, keyspace, shard, timeout, interrupted)
			if err != nil {
				rec.RecordError(err)
				return
			}

			// write the data we need to
			rebuildErr := rebuildCellSrvShard(log, ts, shardInfo, cell, tablets)

			// and unlock
			if err := actionNode.UnlockSrvShard(ts, cell, keyspace, shard, lockPath, rebuildErr); err != nil {
				rec.RecordError(err)
			}
		}(cell)
	}
	wg.Wait()

	return rec.Error()
}