package statesync import ( "context" "errors" "sort" "time" abci "github.com/tendermint/tendermint/abci/types" tmsync "github.com/tendermint/tendermint/libs/sync" "github.com/tendermint/tendermint/p2p" ssproto "github.com/tendermint/tendermint/proto/tendermint/statesync" "github.com/tendermint/tendermint/proxy" sm "github.com/tendermint/tendermint/state" "github.com/tendermint/tendermint/types" ) const ( // SnapshotChannel exchanges snapshot metadata SnapshotChannel = byte(0x60) // ChunkChannel exchanges chunk contents ChunkChannel = byte(0x61) // recentSnapshots is the number of recent snapshots to send and receive per peer. recentSnapshots = 10 ) // Reactor handles state sync, both restoring snapshots for the local node and serving snapshots // for other nodes. type Reactor struct { p2p.BaseReactor conn proxy.AppConnSnapshot connQuery proxy.AppConnQuery tempDir string // This will only be set when a state sync is in progress. It is used to feed received // snapshots and chunks into the sync. mtx tmsync.RWMutex syncer *syncer } // NewReactor creates a new state sync reactor. func NewReactor(conn proxy.AppConnSnapshot, connQuery proxy.AppConnQuery, tempDir string) *Reactor { r := &Reactor{ conn: conn, connQuery: connQuery, } r.BaseReactor = *p2p.NewBaseReactor("StateSync", r) return r } // GetChannels implements p2p.Reactor. func (r *Reactor) GetChannels() []*p2p.ChannelDescriptor { return []*p2p.ChannelDescriptor{ { ID: SnapshotChannel, Priority: 3, SendQueueCapacity: 10, RecvMessageCapacity: snapshotMsgSize, }, { ID: ChunkChannel, Priority: 1, SendQueueCapacity: 4, RecvMessageCapacity: chunkMsgSize, }, } } // OnStart implements p2p.Reactor. func (r *Reactor) OnStart() error { return nil } // AddPeer implements p2p.Reactor. func (r *Reactor) AddPeer(peer p2p.Peer) { r.mtx.RLock() defer r.mtx.RUnlock() if r.syncer != nil { r.syncer.AddPeer(peer) } } // RemovePeer implements p2p.Reactor. func (r *Reactor) RemovePeer(peer p2p.Peer, reason interface{}) { r.mtx.RLock() defer r.mtx.RUnlock() if r.syncer != nil { r.syncer.RemovePeer(peer) } } // Receive implements p2p.Reactor. // XXX: do not call any methods that can block or incur heavy processing. // https://github.com/tendermint/tendermint/issues/2888 func (r *Reactor) Receive(chID byte, src p2p.Peer, msgBytes []byte) { if !r.IsRunning() { return } msg, err := decodeMsg(msgBytes) if err != nil { r.Logger.Error("Error decoding message", "src", src, "chId", chID, "err", err) r.Switch.StopPeerForError(src, err) return } err = validateMsg(msg) if err != nil { r.Logger.Error("Invalid message", "peer", src, "msg", msg, "err", err) r.Switch.StopPeerForError(src, err) return } switch chID { case SnapshotChannel: switch msg := msg.(type) { case *ssproto.SnapshotsRequest: snapshots, err := r.recentSnapshots(recentSnapshots) if err != nil { r.Logger.Error("Failed to fetch snapshots", "err", err) return } for _, snapshot := range snapshots { r.Logger.Debug("Advertising snapshot", "height", snapshot.Height, "format", snapshot.Format, "peer", src.ID()) src.Send(chID, mustEncodeMsg(&ssproto.SnapshotsResponse{ Height: snapshot.Height, Format: snapshot.Format, Chunks: snapshot.Chunks, Hash: snapshot.Hash, Metadata: snapshot.Metadata, })) } case *ssproto.SnapshotsResponse: r.mtx.RLock() defer r.mtx.RUnlock() if r.syncer == nil { r.Logger.Debug("Received unexpected snapshot, no state sync in progress") return } r.Logger.Debug("Received snapshot", "height", msg.Height, "format", msg.Format, "peer", src.ID()) _, err := r.syncer.AddSnapshot(src, &snapshot{ Height: msg.Height, Format: msg.Format, Chunks: msg.Chunks, Hash: msg.Hash, Metadata: msg.Metadata, }) if err != nil { r.Logger.Error("Failed to add snapshot", "height", msg.Height, "format", msg.Format, "peer", src.ID(), "err", err) return } default: r.Logger.Error("Received unknown message %T", msg) } case ChunkChannel: switch msg := msg.(type) { case *ssproto.ChunkRequest: r.Logger.Debug("Received chunk request", "height", msg.Height, "format", msg.Format, "chunk", msg.Index, "peer", src.ID()) resp, err := r.conn.LoadSnapshotChunkSync(context.Background(), abci.RequestLoadSnapshotChunk{ Height: msg.Height, Format: msg.Format, Chunk: msg.Index, }) if err != nil { r.Logger.Error("Failed to load chunk", "height", msg.Height, "format", msg.Format, "chunk", msg.Index, "err", err) return } r.Logger.Debug("Sending chunk", "height", msg.Height, "format", msg.Format, "chunk", msg.Index, "peer", src.ID()) src.Send(ChunkChannel, mustEncodeMsg(&ssproto.ChunkResponse{ Height: msg.Height, Format: msg.Format, Index: msg.Index, Chunk: resp.Chunk, Missing: resp.Chunk == nil, })) case *ssproto.ChunkResponse: r.mtx.RLock() defer r.mtx.RUnlock() if r.syncer == nil { r.Logger.Debug("Received unexpected chunk, no state sync in progress", "peer", src.ID()) return } r.Logger.Debug("Received chunk, adding to sync", "height", msg.Height, "format", msg.Format, "chunk", msg.Index, "peer", src.ID()) _, err := r.syncer.AddChunk(&chunk{ Height: msg.Height, Format: msg.Format, Index: msg.Index, Chunk: msg.Chunk, Sender: src.ID(), }) if err != nil { r.Logger.Error("Failed to add chunk", "height", msg.Height, "format", msg.Format, "chunk", msg.Index, "err", err) return } default: r.Logger.Error("Received unknown message %T", msg) } default: r.Logger.Error("Received message on invalid channel %x", chID) } } // recentSnapshots fetches the n most recent snapshots from the app func (r *Reactor) recentSnapshots(n uint32) ([]*snapshot, error) { resp, err := r.conn.ListSnapshotsSync(context.Background(), abci.RequestListSnapshots{}) if err != nil { return nil, err } sort.Slice(resp.Snapshots, func(i, j int) bool { a := resp.Snapshots[i] b := resp.Snapshots[j] switch { case a.Height > b.Height: return true case a.Height == b.Height && a.Format > b.Format: return true default: return false } }) snapshots := make([]*snapshot, 0, n) for i, s := range resp.Snapshots { if i >= recentSnapshots { break } snapshots = append(snapshots, &snapshot{ Height: s.Height, Format: s.Format, Chunks: s.Chunks, Hash: s.Hash, Metadata: s.Metadata, }) } return snapshots, nil } // Sync runs a state sync, returning the new state and last commit at the snapshot height. // The caller must store the state and commit in the state database and block store. func (r *Reactor) Sync(stateProvider StateProvider, discoveryTime time.Duration) (sm.State, *types.Commit, error) { r.mtx.Lock() if r.syncer != nil { r.mtx.Unlock() return sm.State{}, nil, errors.New("a state sync is already in progress") } r.syncer = newSyncer(r.Logger, r.conn, r.connQuery, stateProvider, r.tempDir) r.mtx.Unlock() // Request snapshots from all currently connected peers r.Logger.Debug("Requesting snapshots from known peers") r.Switch.Broadcast(SnapshotChannel, mustEncodeMsg(&ssproto.SnapshotsRequest{})) state, commit, err := r.syncer.SyncAny(discoveryTime) r.mtx.Lock() r.syncer = nil r.mtx.Unlock() return state, commit, err }