// Package sync includes all chain-synchronization logic for the beacon node, // including gossip-sub validators for blocks, attestations, and other p2p // messages, as well as ability to process and respond to block requests // by peers. package sync import ( "context" "sync" "time" lru "github.com/hashicorp/golang-lru" "github.com/libp2p/go-libp2p-core/peer" "github.com/pkg/errors" ethpb "github.com/prysmaticlabs/ethereumapis/eth/v1alpha1" "github.com/prysmaticlabs/prysm/beacon-chain/blockchain" "github.com/prysmaticlabs/prysm/beacon-chain/cache" "github.com/prysmaticlabs/prysm/beacon-chain/core/feed" blockfeed "github.com/prysmaticlabs/prysm/beacon-chain/core/feed/block" "github.com/prysmaticlabs/prysm/beacon-chain/core/feed/operation" statefeed "github.com/prysmaticlabs/prysm/beacon-chain/core/feed/state" "github.com/prysmaticlabs/prysm/beacon-chain/core/helpers" "github.com/prysmaticlabs/prysm/beacon-chain/db" "github.com/prysmaticlabs/prysm/beacon-chain/operations/attestations" "github.com/prysmaticlabs/prysm/beacon-chain/operations/slashings" "github.com/prysmaticlabs/prysm/beacon-chain/operations/voluntaryexits" "github.com/prysmaticlabs/prysm/beacon-chain/p2p" "github.com/prysmaticlabs/prysm/beacon-chain/state/stategen" "github.com/prysmaticlabs/prysm/shared" "github.com/prysmaticlabs/prysm/shared/roughtime" "github.com/prysmaticlabs/prysm/shared/runutil" ) var _ = shared.Service(&Service{}) const rangeLimit = 1000 const seenBlockSize = 1000 const seenAttSize = 10000 const seenExitSize = 100 const seenAttesterSlashingSize = 100 const seenProposerSlashingSize = 100 const syncMetricsInterval = 10 * time.Second // Config to set up the regular sync service. type Config struct { P2P p2p.P2P DB db.NoHeadAccessDatabase AttPool attestations.Pool ExitPool *voluntaryexits.Pool SlashingPool *slashings.Pool Chain blockchainService InitialSync Checker StateNotifier statefeed.Notifier BlockNotifier blockfeed.Notifier AttestationNotifier operation.Notifier StateSummaryCache *cache.StateSummaryCache StateGen *stategen.State } // This defines the interface for interacting with block chain service type blockchainService interface { blockchain.BlockReceiver blockchain.HeadFetcher blockchain.FinalizationFetcher blockchain.ForkFetcher blockchain.AttestationReceiver blockchain.TimeFetcher blockchain.GenesisFetcher blockchain.CanonicalFetcher } // Service is responsible for handling all run time p2p related operations as the // main entry point for network messages. type Service struct { ctx context.Context cancel context.CancelFunc p2p p2p.P2P db db.NoHeadAccessDatabase attPool attestations.Pool exitPool *voluntaryexits.Pool slashingPool *slashings.Pool chain blockchainService slotToPendingBlocks map[uint64]*ethpb.SignedBeaconBlock seenPendingBlocks map[[32]byte]bool blkRootToPendingAtts map[[32]byte][]*ethpb.SignedAggregateAttestationAndProof pendingAttsLock sync.RWMutex pendingQueueLock sync.RWMutex chainStarted bool initialSync Checker validateBlockLock sync.RWMutex stateNotifier statefeed.Notifier blockNotifier blockfeed.Notifier rateLimiter *limiter attestationNotifier operation.Notifier seenBlockLock sync.RWMutex seenBlockCache *lru.Cache seenAttestationLock sync.RWMutex seenAttestationCache *lru.Cache seenExitLock sync.RWMutex seenExitCache *lru.Cache seenProposerSlashingLock sync.RWMutex seenProposerSlashingCache *lru.Cache seenAttesterSlashingLock sync.RWMutex seenAttesterSlashingCache *lru.Cache stateSummaryCache *cache.StateSummaryCache stateGen *stategen.State } // NewRegularSync service. func NewRegularSync(cfg *Config) *Service { rLimiter := newRateLimiter(cfg.P2P) ctx, cancel := context.WithCancel(context.Background()) r := &Service{ ctx: ctx, cancel: cancel, db: cfg.DB, p2p: cfg.P2P, attPool: cfg.AttPool, exitPool: cfg.ExitPool, slashingPool: cfg.SlashingPool, chain: cfg.Chain, initialSync: cfg.InitialSync, attestationNotifier: cfg.AttestationNotifier, slotToPendingBlocks: make(map[uint64]*ethpb.SignedBeaconBlock), seenPendingBlocks: make(map[[32]byte]bool), blkRootToPendingAtts: make(map[[32]byte][]*ethpb.SignedAggregateAttestationAndProof), stateNotifier: cfg.StateNotifier, blockNotifier: cfg.BlockNotifier, stateSummaryCache: cfg.StateSummaryCache, stateGen: cfg.StateGen, rateLimiter: rLimiter, } go r.registerHandlers() return r } // Start the regular sync service. func (s *Service) Start() { if err := s.initCaches(); err != nil { panic(err) } s.p2p.AddConnectionHandler(s.reValidatePeer) s.p2p.AddDisconnectionHandler(func(_ context.Context, _ peer.ID) error { // no-op return nil }) s.p2p.AddPingMethod(s.sendPingRequest) s.processPendingBlocksQueue() s.processPendingAttsQueue() s.maintainPeerStatuses() s.resyncIfBehind() // Update sync metrics. runutil.RunEvery(s.ctx, syncMetricsInterval, s.updateMetrics) } // Stop the regular sync service. func (s *Service) Stop() error { defer func() { if s.rateLimiter != nil { s.rateLimiter.free() s.rateLimiter = nil } }() defer s.cancel() return nil } // Status of the currently running regular sync service. func (s *Service) Status() error { if s.chainStarted { if s.initialSync.Syncing() { return errors.New("waiting for initial sync") } // If our head slot is on a previous epoch and our peers are reporting their head block are // in the most recent epoch, then we might be out of sync. if headEpoch := helpers.SlotToEpoch(s.chain.HeadSlot()); headEpoch+1 < helpers.SlotToEpoch(s.chain.CurrentSlot()) && headEpoch+1 < s.p2p.Peers().HighestEpoch() { return errors.New("out of sync") } } return nil } // This initializes the caches to update seen beacon objects coming in from the wire // and prevent DoS. func (s *Service) initCaches() error { blkCache, err := lru.New(seenBlockSize) if err != nil { return err } attCache, err := lru.New(seenAttSize) if err != nil { return err } exitCache, err := lru.New(seenExitSize) if err != nil { return err } attesterSlashingCache, err := lru.New(seenAttesterSlashingSize) if err != nil { return err } proposerSlashingCache, err := lru.New(seenProposerSlashingSize) if err != nil { return err } s.seenBlockCache = blkCache s.seenAttestationCache = attCache s.seenExitCache = exitCache s.seenAttesterSlashingCache = attesterSlashingCache s.seenProposerSlashingCache = proposerSlashingCache return nil } func (s *Service) registerHandlers() { // Wait until chain start. stateChannel := make(chan *feed.Event, 1) stateSub := s.stateNotifier.StateFeed().Subscribe(stateChannel) defer stateSub.Unsubscribe() for s.chainStarted == false { select { case event := <-stateChannel: if event.Type == statefeed.Initialized { data, ok := event.Data.(*statefeed.InitializedData) if !ok { log.Error("Event feed data is not type *statefeed.InitializedData") return } log.WithField("starttime", data.StartTime).Debug("Received state initialized event") // Register respective rpc and pubsub handlers at state initialized event. s.registerRPCHandlers() s.registerSubscribers() if data.StartTime.After(roughtime.Now()) { stateSub.Unsubscribe() time.Sleep(roughtime.Until(data.StartTime)) } s.chainStarted = true } case <-s.ctx.Done(): log.Debug("Context closed, exiting goroutine") return case err := <-stateSub.Err(): log.WithError(err).Error("Subscription to state notifier failed") return } } } // Checker defines a struct which can verify whether a node is currently // synchronizing a chain with the rest of peers in the network. type Checker interface { Syncing() bool Status() error Resync() error }