You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

642 lines
17 KiB

package blocksync
import (
"context"
"fmt"
"runtime/debug"
"sync"
"time"
"github.com/tendermint/tendermint/internal/consensus"
"github.com/tendermint/tendermint/internal/p2p"
sm "github.com/tendermint/tendermint/internal/state"
"github.com/tendermint/tendermint/internal/store"
"github.com/tendermint/tendermint/libs/log"
"github.com/tendermint/tendermint/libs/service"
tmsync "github.com/tendermint/tendermint/libs/sync"
bcproto "github.com/tendermint/tendermint/proto/tendermint/blocksync"
"github.com/tendermint/tendermint/types"
)
var _ service.Service = (*Reactor)(nil)
const (
// BlockSyncChannel is a channel for blocks and status updates
BlockSyncChannel = p2p.ChannelID(0x40)
trySyncIntervalMS = 10
// ask for best height every 10s
statusUpdateIntervalSeconds = 10
// check if we should switch to consensus reactor
switchToConsensusIntervalSeconds = 1
// switch to consensus after this duration of inactivity
syncTimeout = 60 * time.Second
)
func GetChannelDescriptor() *p2p.ChannelDescriptor {
return &p2p.ChannelDescriptor{
ID: BlockSyncChannel,
MessageType: new(bcproto.Message),
Priority: 5,
SendQueueCapacity: 1000,
RecvBufferCapacity: 1024,
RecvMessageCapacity: MaxMsgSize,
}
}
type consensusReactor interface {
// For when we switch from block sync reactor to the consensus
// machine.
SwitchToConsensus(ctx context.Context, state sm.State, skipWAL bool)
}
type peerError struct {
err error
peerID types.NodeID
}
func (e peerError) Error() string {
return fmt.Sprintf("error with peer %v: %s", e.peerID, e.err.Error())
}
// Reactor handles long-term catchup syncing.
type Reactor struct {
service.BaseService
// immutable
initialState sm.State
blockExec *sm.BlockExecutor
store *store.BlockStore
pool *BlockPool
consReactor consensusReactor
blockSync *tmsync.AtomicBool
blockSyncCh *p2p.Channel
// blockSyncOutBridgeCh defines a channel that acts as a bridge between sending Envelope
// messages that the reactor will consume in processBlockSyncCh and receiving messages
// from the peer updates channel and other goroutines. We do this instead of directly
// sending on blockSyncCh.Out to avoid race conditions in the case where other goroutines
// send Envelopes directly to the to blockSyncCh.Out channel, since processBlockSyncCh
// may close the blockSyncCh.Out channel at the same time that other goroutines send to
// blockSyncCh.Out.
blockSyncOutBridgeCh chan p2p.Envelope
peerUpdates *p2p.PeerUpdates
closeCh chan struct{}
requestsCh <-chan BlockRequest
errorsCh <-chan peerError
// poolWG is used to synchronize the graceful shutdown of the poolRoutine and
// requestRoutine spawned goroutines when stopping the reactor and before
// stopping the p2p Channel(s).
poolWG sync.WaitGroup
metrics *consensus.Metrics
syncStartTime time.Time
}
// NewReactor returns new reactor instance.
func NewReactor(
logger log.Logger,
state sm.State,
blockExec *sm.BlockExecutor,
store *store.BlockStore,
consReactor consensusReactor,
blockSyncCh *p2p.Channel,
peerUpdates *p2p.PeerUpdates,
blockSync bool,
metrics *consensus.Metrics,
) (*Reactor, error) {
if state.LastBlockHeight != store.Height() {
return nil, fmt.Errorf("state (%v) and store (%v) height mismatch", state.LastBlockHeight, store.Height())
}
startHeight := store.Height() + 1
if startHeight == 1 {
startHeight = state.InitialHeight
}
requestsCh := make(chan BlockRequest, maxTotalRequesters)
errorsCh := make(chan peerError, maxPeerErrBuffer) // NOTE: The capacity should be larger than the peer count.
r := &Reactor{
initialState: state,
blockExec: blockExec,
store: store,
pool: NewBlockPool(logger, startHeight, requestsCh, errorsCh),
consReactor: consReactor,
blockSync: tmsync.NewBool(blockSync),
requestsCh: requestsCh,
errorsCh: errorsCh,
blockSyncCh: blockSyncCh,
blockSyncOutBridgeCh: make(chan p2p.Envelope),
peerUpdates: peerUpdates,
closeCh: make(chan struct{}),
metrics: metrics,
syncStartTime: time.Time{},
}
r.BaseService = *service.NewBaseService(logger, "BlockSync", r)
return r, nil
}
// OnStart starts separate go routines for each p2p Channel and listens for
// envelopes on each. In addition, it also listens for peer updates and handles
// messages on that p2p channel accordingly. The caller must be sure to execute
// OnStop to ensure the outbound p2p Channels are closed.
//
// If blockSync is enabled, we also start the pool and the pool processing
// goroutine. If the pool fails to start, an error is returned.
func (r *Reactor) OnStart(ctx context.Context) error {
if r.blockSync.IsSet() {
if err := r.pool.Start(ctx); err != nil {
return err
}
r.poolWG.Add(1)
go r.requestRoutine()
r.poolWG.Add(1)
go r.poolRoutine(false)
}
go r.processBlockSyncCh()
go r.processPeerUpdates()
return nil
}
// OnStop stops the reactor by signaling to all spawned goroutines to exit and
// blocking until they all exit.
func (r *Reactor) OnStop() {
if r.blockSync.IsSet() {
if err := r.pool.Stop(); err != nil {
r.Logger.Error("failed to stop pool", "err", err)
}
}
// wait for the poolRoutine and requestRoutine goroutines to gracefully exit
r.poolWG.Wait()
// Close closeCh to signal to all spawned goroutines to gracefully exit. All
// p2p Channels should execute Close().
close(r.closeCh)
// Wait for all p2p Channels to be closed before returning. This ensures we
// can easily reason about synchronization of all p2p Channels and ensure no
// panics will occur.
<-r.blockSyncCh.Done()
<-r.peerUpdates.Done()
}
// respondToPeer loads a block and sends it to the requesting peer, if we have it.
// Otherwise, we'll respond saying we do not have it.
func (r *Reactor) respondToPeer(msg *bcproto.BlockRequest, peerID types.NodeID) {
block := r.store.LoadBlock(msg.Height)
if block != nil {
blockProto, err := block.ToProto()
if err != nil {
r.Logger.Error("failed to convert msg to protobuf", "err", err)
return
}
r.blockSyncCh.Out <- p2p.Envelope{
To: peerID,
Message: &bcproto.BlockResponse{Block: blockProto},
}
return
}
r.Logger.Info("peer requesting a block we do not have", "peer", peerID, "height", msg.Height)
r.blockSyncCh.Out <- p2p.Envelope{
To: peerID,
Message: &bcproto.NoBlockResponse{Height: msg.Height},
}
}
// handleBlockSyncMessage handles envelopes sent from peers on the
// BlockSyncChannel. It returns an error only if the Envelope.Message is unknown
// for this channel. This should never be called outside of handleMessage.
func (r *Reactor) handleBlockSyncMessage(envelope p2p.Envelope) error {
logger := r.Logger.With("peer", envelope.From)
switch msg := envelope.Message.(type) {
case *bcproto.BlockRequest:
r.respondToPeer(msg, envelope.From)
case *bcproto.BlockResponse:
block, err := types.BlockFromProto(msg.Block)
if err != nil {
logger.Error("failed to convert block from proto", "err", err)
return err
}
r.pool.AddBlock(envelope.From, block, block.Size())
case *bcproto.StatusRequest:
r.blockSyncCh.Out <- p2p.Envelope{
To: envelope.From,
Message: &bcproto.StatusResponse{
Height: r.store.Height(),
Base: r.store.Base(),
},
}
case *bcproto.StatusResponse:
r.pool.SetPeerRange(envelope.From, msg.Base, msg.Height)
case *bcproto.NoBlockResponse:
logger.Debug("peer does not have the requested block", "height", msg.Height)
default:
return fmt.Errorf("received unknown message: %T", msg)
}
return nil
}
// handleMessage handles an Envelope sent from a peer on a specific p2p Channel.
// It will handle errors and any possible panics gracefully. A caller can handle
// any error returned by sending a PeerError on the respective channel.
func (r *Reactor) handleMessage(chID p2p.ChannelID, envelope p2p.Envelope) (err error) {
defer func() {
if e := recover(); e != nil {
err = fmt.Errorf("panic in processing message: %v", e)
r.Logger.Error(
"recovering from processing message panic",
"err", err,
"stack", string(debug.Stack()),
)
}
}()
r.Logger.Debug("received message", "message", envelope.Message, "peer", envelope.From)
switch chID {
case BlockSyncChannel:
err = r.handleBlockSyncMessage(envelope)
default:
err = fmt.Errorf("unknown channel ID (%d) for envelope (%v)", chID, envelope)
}
return err
}
// processBlockSyncCh initiates a blocking process where we listen for and handle
// envelopes on the BlockSyncChannel and blockSyncOutBridgeCh. Any error encountered during
// message execution will result in a PeerError being sent on the BlockSyncChannel.
// When the reactor is stopped, we will catch the signal and close the p2p Channel
// gracefully.
func (r *Reactor) processBlockSyncCh() {
defer r.blockSyncCh.Close()
for {
select {
case envelope := <-r.blockSyncCh.In:
if err := r.handleMessage(r.blockSyncCh.ID, envelope); err != nil {
r.Logger.Error("failed to process message", "ch_id", r.blockSyncCh.ID, "envelope", envelope, "err", err)
r.blockSyncCh.Error <- p2p.PeerError{
NodeID: envelope.From,
Err: err,
}
}
case envelope := <-r.blockSyncOutBridgeCh:
r.blockSyncCh.Out <- envelope
case <-r.closeCh:
r.Logger.Debug("stopped listening on block sync channel; closing...")
return
}
}
}
// processPeerUpdate processes a PeerUpdate.
func (r *Reactor) processPeerUpdate(peerUpdate p2p.PeerUpdate) {
r.Logger.Debug("received peer update", "peer", peerUpdate.NodeID, "status", peerUpdate.Status)
// XXX: Pool#RedoRequest can sometimes give us an empty peer.
if len(peerUpdate.NodeID) == 0 {
return
}
switch peerUpdate.Status {
case p2p.PeerStatusUp:
// send a status update the newly added peer
r.blockSyncOutBridgeCh <- p2p.Envelope{
To: peerUpdate.NodeID,
Message: &bcproto.StatusResponse{
Base: r.store.Base(),
Height: r.store.Height(),
},
}
case p2p.PeerStatusDown:
r.pool.RemovePeer(peerUpdate.NodeID)
}
}
// processPeerUpdates initiates a blocking process where we listen for and handle
// PeerUpdate messages. When the reactor is stopped, we will catch the signal and
// close the p2p PeerUpdatesCh gracefully.
func (r *Reactor) processPeerUpdates() {
defer r.peerUpdates.Close()
for {
select {
case peerUpdate := <-r.peerUpdates.Updates():
r.processPeerUpdate(peerUpdate)
case <-r.closeCh:
r.Logger.Debug("stopped listening on peer updates channel; closing...")
return
}
}
}
// SwitchToBlockSync is called by the state sync reactor when switching to fast
// sync.
func (r *Reactor) SwitchToBlockSync(ctx context.Context, state sm.State) error {
r.blockSync.Set()
r.initialState = state
r.pool.height = state.LastBlockHeight + 1
if err := r.pool.Start(ctx); err != nil {
return err
}
r.syncStartTime = time.Now()
r.poolWG.Add(1)
go r.requestRoutine()
r.poolWG.Add(1)
go r.poolRoutine(true)
return nil
}
func (r *Reactor) requestRoutine() {
statusUpdateTicker := time.NewTicker(statusUpdateIntervalSeconds * time.Second)
defer statusUpdateTicker.Stop()
defer r.poolWG.Done()
for {
select {
case <-r.closeCh:
return
case <-r.pool.Quit():
return
case request := <-r.requestsCh:
r.blockSyncOutBridgeCh <- p2p.Envelope{
To: request.PeerID,
Message: &bcproto.BlockRequest{Height: request.Height},
}
case pErr := <-r.errorsCh:
r.blockSyncCh.Error <- p2p.PeerError{
NodeID: pErr.peerID,
Err: pErr.err,
}
case <-statusUpdateTicker.C:
r.poolWG.Add(1)
go func() {
defer r.poolWG.Done()
r.blockSyncOutBridgeCh <- p2p.Envelope{
Broadcast: true,
Message: &bcproto.StatusRequest{},
}
}()
}
}
}
func (r *Reactor) stopCtx() context.Context {
ctx, cancel := context.WithCancel(context.Background())
go func() {
<-r.closeCh
cancel()
}()
return ctx
}
// poolRoutine handles messages from the poolReactor telling the reactor what to
// do.
//
// NOTE: Don't sleep in the FOR_LOOP or otherwise slow it down!
func (r *Reactor) poolRoutine(stateSynced bool) {
var (
trySyncTicker = time.NewTicker(trySyncIntervalMS * time.Millisecond)
switchToConsensusTicker = time.NewTicker(switchToConsensusIntervalSeconds * time.Second)
blocksSynced = uint64(0)
chainID = r.initialState.ChainID
state = r.initialState
lastHundred = time.Now()
lastRate = 0.0
didProcessCh = make(chan struct{}, 1)
ctx = r.stopCtx()
)
defer trySyncTicker.Stop()
defer switchToConsensusTicker.Stop()
defer r.poolWG.Done()
FOR_LOOP:
for {
select {
case <-switchToConsensusTicker.C:
var (
height, numPending, lenRequesters = r.pool.GetStatus()
lastAdvance = r.pool.LastAdvance()
)
r.Logger.Debug(
"consensus ticker",
"num_pending", numPending,
"total", lenRequesters,
"height", height,
)
switch {
case r.pool.IsCaughtUp():
r.Logger.Info("switching to consensus reactor", "height", height)
case time.Since(lastAdvance) > syncTimeout:
r.Logger.Error("no progress since last advance", "last_advance", lastAdvance)
default:
r.Logger.Info(
"not caught up yet",
"height", height,
"max_peer_height", r.pool.MaxPeerHeight(),
"timeout_in", syncTimeout-time.Since(lastAdvance),
)
continue
}
if err := r.pool.Stop(); err != nil {
r.Logger.Error("failed to stop pool", "err", err)
}
r.blockSync.UnSet()
if r.consReactor != nil {
r.consReactor.SwitchToConsensus(ctx, state, blocksSynced > 0 || stateSynced)
}
break FOR_LOOP
case <-trySyncTicker.C:
select {
case didProcessCh <- struct{}{}:
default:
}
case <-didProcessCh:
// NOTE: It is a subtle mistake to process more than a single block at a
// time (e.g. 10) here, because we only send one BlockRequest per loop
// iteration. The ratio mismatch can result in starving of blocks, i.e. a
// sudden burst of requests and responses, and repeat. Consequently, it is
// better to split these routines rather than coupling them as it is
// written here.
//
// TODO: Uncouple from request routine.
// see if there are any blocks to sync
first, second := r.pool.PeekTwoBlocks()
if first == nil || second == nil {
// we need both to sync the first block
continue FOR_LOOP
} else {
// try again quickly next loop
didProcessCh <- struct{}{}
}
var (
firstParts = first.MakePartSet(types.BlockPartSizeBytes)
firstPartSetHeader = firstParts.Header()
firstID = types.BlockID{Hash: first.Hash(), PartSetHeader: firstPartSetHeader}
)
// Finally, verify the first block using the second's commit.
//
// NOTE: We can probably make this more efficient, but note that calling
// first.Hash() doesn't verify the tx contents, so MakePartSet() is
// currently necessary.
err := state.Validators.VerifyCommitLight(chainID, firstID, first.Height, second.LastCommit)
if err != nil {
err = fmt.Errorf("invalid last commit: %w", err)
r.Logger.Error(
err.Error(),
"last_commit", second.LastCommit,
"block_id", firstID,
"height", first.Height,
)
// NOTE: We've already removed the peer's request, but we still need
// to clean up the rest.
peerID := r.pool.RedoRequest(first.Height)
r.blockSyncCh.Error <- p2p.PeerError{
NodeID: peerID,
Err: err,
}
peerID2 := r.pool.RedoRequest(second.Height)
if peerID2 != peerID {
r.blockSyncCh.Error <- p2p.PeerError{
NodeID: peerID2,
Err: err,
}
}
continue FOR_LOOP
} else {
r.pool.PopRequest()
// TODO: batch saves so we do not persist to disk every block
r.store.SaveBlock(first, firstParts, second.LastCommit)
var err error
// TODO: Same thing for app - but we would need a way to get the hash
// without persisting the state.
state, err = r.blockExec.ApplyBlock(ctx, state, firstID, first)
if err != nil {
// TODO: This is bad, are we zombie?
panic(fmt.Sprintf("failed to process committed block (%d:%X): %v", first.Height, first.Hash(), err))
}
r.metrics.RecordConsMetrics(first)
blocksSynced++
if blocksSynced%100 == 0 {
lastRate = 0.9*lastRate + 0.1*(100/time.Since(lastHundred).Seconds())
r.Logger.Info(
"block sync rate",
"height", r.pool.height,
"max_peer_height", r.pool.MaxPeerHeight(),
"blocks/s", lastRate,
)
lastHundred = time.Now()
}
}
continue FOR_LOOP
case <-r.closeCh:
break FOR_LOOP
case <-r.pool.Quit():
break FOR_LOOP
}
}
}
func (r *Reactor) GetMaxPeerBlockHeight() int64 {
return r.pool.MaxPeerHeight()
}
func (r *Reactor) GetTotalSyncedTime() time.Duration {
if !r.blockSync.IsSet() || r.syncStartTime.IsZero() {
return time.Duration(0)
}
return time.Since(r.syncStartTime)
}
func (r *Reactor) GetRemainingSyncTime() time.Duration {
if !r.blockSync.IsSet() {
return time.Duration(0)
}
targetSyncs := r.pool.targetSyncBlocks()
currentSyncs := r.store.Height() - r.pool.startHeight + 1
lastSyncRate := r.pool.getLastSyncRate()
if currentSyncs < 0 || lastSyncRate < 0.001 {
return time.Duration(0)
}
remain := float64(targetSyncs-currentSyncs) / lastSyncRate
return time.Duration(int64(remain * float64(time.Second)))
}