core, eth, les: support resuming fast sync on heavy rollback (#3743)

This commit is contained in:
Péter Szilágyi 2017-03-22 02:37:24 +02:00 committed by Felix Lange
parent 06d6685eb5
commit 9b84caf3a5
6 changed files with 69 additions and 34 deletions

View File

@ -182,16 +182,25 @@ func (self *BlockChain) loadLastState() error {
head := GetHeadBlockHash(self.chainDb)
if head == (common.Hash{}) {
// Corrupt or empty database, init from scratch
self.Reset()
} else {
if block := self.GetBlockByHash(head); block != nil {
// Block found, set as the current head
self.currentBlock = block
} else {
// Corrupt or empty database, init from scratch
self.Reset()
}
log.Warn("Empty database, resetting chain")
return self.Reset()
}
// Make sure the entire head block is available
currentBlock := self.GetBlockByHash(head)
if currentBlock == nil {
// Corrupt or empty database, init from scratch
log.Warn("Head block missing, resetting chain", "hash", head)
return self.Reset()
}
// Make sure the state associated with the block is available
if _, err := state.New(currentBlock.Root(), self.chainDb); err != nil {
// Dangling block without a state associated, init from scratch
log.Warn("Head state missing, resetting chain", "number", currentBlock.Number(), "hash", currentBlock.Hash())
return self.Reset()
}
// Everything seems to be fine, set as the head block
self.currentBlock = currentBlock
// Restore the last known head header
currentHeader := self.currentBlock.Header()
if head := GetHeadHeaderHash(self.chainDb); head != (common.Hash{}) {
@ -200,6 +209,7 @@ func (self *BlockChain) loadLastState() error {
}
}
self.hc.SetCurrentHeader(currentHeader)
// Restore the last known head fast block
self.currentFastBlock = self.currentBlock
if head := GetHeadFastBlockHash(self.chainDb); head != (common.Hash{}) {
@ -233,14 +243,18 @@ func (self *BlockChain) loadLastState() error {
// above the new head will be deleted and the new one set. In the case of blocks
// though, the head may be further rewound if block bodies are missing (non-archive
// nodes after a fast sync).
func (bc *BlockChain) SetHead(head uint64) {
func (bc *BlockChain) SetHead(head uint64) error {
log.Warn("Rewinding blockchain", "target", head)
bc.mu.Lock()
defer bc.mu.Unlock()
// Rewind the header chain, deleting all block bodies until then
delFn := func(hash common.Hash, num uint64) {
DeleteBody(bc.chainDb, hash, num)
}
bc.hc.SetHead(head, delFn)
currentHeader := bc.hc.CurrentHeader()
// Clear out any stale content from the caches
bc.bodyCache.Purge()
@ -248,29 +262,34 @@ func (bc *BlockChain) SetHead(head uint64) {
bc.blockCache.Purge()
bc.futureBlocks.Purge()
// Update all computed fields to the new head
currentHeader := bc.hc.CurrentHeader()
// Rewind the block chain, ensuring we don't end up with a stateless head block
if bc.currentBlock != nil && currentHeader.Number.Uint64() < bc.currentBlock.NumberU64() {
bc.currentBlock = bc.GetBlock(currentHeader.Hash(), currentHeader.Number.Uint64())
}
if bc.currentBlock != nil {
if _, err := state.New(bc.currentBlock.Root(), bc.chainDb); err != nil {
// Rewound state missing, rolled back to before pivot, reset to genesis
bc.currentBlock = nil
}
}
// Rewind the fast block in a simpleton way to the target head
if bc.currentFastBlock != nil && currentHeader.Number.Uint64() < bc.currentFastBlock.NumberU64() {
bc.currentFastBlock = bc.GetBlock(currentHeader.Hash(), currentHeader.Number.Uint64())
}
// If either blocks reached nil, reset to the genesis state
if bc.currentBlock == nil {
bc.currentBlock = bc.genesisBlock
}
if bc.currentFastBlock == nil {
bc.currentFastBlock = bc.genesisBlock
}
if err := WriteHeadBlockHash(bc.chainDb, bc.currentBlock.Hash()); err != nil {
log.Crit("Failed to reset head full block", "err", err)
}
if err := WriteHeadFastBlockHash(bc.chainDb, bc.currentFastBlock.Hash()); err != nil {
log.Crit("Failed to reset head fast block", "err", err)
}
bc.loadLastState()
return bc.loadLastState()
}
// FastSyncCommitHead sets the current head block to the one defined by the hash
@ -378,16 +397,17 @@ func (self *BlockChain) StateAt(root common.Hash) (*state.StateDB, error) {
}
// Reset purges the entire blockchain, restoring it to its genesis state.
func (bc *BlockChain) Reset() {
bc.ResetWithGenesisBlock(bc.genesisBlock)
func (bc *BlockChain) Reset() error {
return bc.ResetWithGenesisBlock(bc.genesisBlock)
}
// ResetWithGenesisBlock purges the entire blockchain, restoring it to the
// specified genesis state.
func (bc *BlockChain) ResetWithGenesisBlock(genesis *types.Block) {
func (bc *BlockChain) ResetWithGenesisBlock(genesis *types.Block) error {
// Dump the entire block chain and purge the caches
bc.SetHead(0)
if err := bc.SetHead(0); err != nil {
return err
}
bc.mu.Lock()
defer bc.mu.Unlock()
@ -404,6 +424,8 @@ func (bc *BlockChain) ResetWithGenesisBlock(genesis *types.Block) {
bc.hc.SetGenesis(bc.genesisBlock.Header())
bc.hc.SetCurrentHeader(bc.genesisBlock.Header())
bc.currentFastBlock = bc.genesisBlock
return nil
}
// Export writes the active chain to the given writer.
@ -790,12 +812,15 @@ func (self *BlockChain) InsertReceiptChain(blockChain types.Blocks, receiptChain
}
// Update the head fast sync block if better
self.mu.Lock()
head := blockChain[len(errs)-1]
if self.GetTd(self.currentFastBlock.Hash(), self.currentFastBlock.NumberU64()).Cmp(self.GetTd(head.Hash(), head.NumberU64())) < 0 {
if err := WriteHeadFastBlockHash(self.chainDb, head.Hash()); err != nil {
log.Crit("Failed to update head fast block hash", "err", err)
if td := self.GetTd(head.Hash(), head.NumberU64()); td != nil { // Rewind may have occurred, skip in that case
if self.GetTd(self.currentFastBlock.Hash(), self.currentFastBlock.NumberU64()).Cmp(td) < 0 {
if err := WriteHeadFastBlockHash(self.chainDb, head.Hash()); err != nil {
log.Crit("Failed to update head fast block hash", "err", err)
}
self.currentFastBlock = head
}
self.currentFastBlock = head
}
self.mu.Unlock()

View File

@ -51,6 +51,7 @@ func (b *EthApiBackend) CurrentBlock() *types.Block {
}
func (b *EthApiBackend) SetHead(number uint64) {
b.eth.protocolManager.downloader.Cancel()
b.eth.blockchain.SetHead(number)
}

View File

@ -277,7 +277,7 @@ func (d *Downloader) UnregisterPeer(id string) error {
d.cancelLock.RUnlock()
if master {
d.cancel()
d.Cancel()
}
return nil
}
@ -352,7 +352,7 @@ func (d *Downloader) synchronise(id string, hash common.Hash, td *big.Int, mode
d.cancelPeer = id
d.cancelLock.Unlock()
defer d.cancel() // No matter what, we can't leave the cancel channel open
defer d.Cancel() // No matter what, we can't leave the cancel channel open
// Set the requested sync mode, unless it's forbidden
d.mode = mode
@ -473,7 +473,7 @@ func (d *Downloader) spawnSync(origin uint64, fetchers ...func() error) error {
}
}
d.queue.Close()
d.cancel()
d.Cancel()
wg.Wait()
// If sync failed in the critical section, bump the fail counter
@ -483,9 +483,9 @@ func (d *Downloader) spawnSync(origin uint64, fetchers ...func() error) error {
return err
}
// cancel cancels all of the operations and resets the queue. It returns true
// Cancel cancels all of the operations and resets the queue. It returns true
// if the cancel operation was completed.
func (d *Downloader) cancel() {
func (d *Downloader) Cancel() {
// Close the current cancel channel
d.cancelLock.Lock()
if d.cancelCh != nil {
@ -512,7 +512,7 @@ func (d *Downloader) Terminate() {
d.quitLock.Unlock()
// Cancel any pending download requests
d.cancel()
d.Cancel()
}
// fetchHeight retrieves the head header of the remote peer to aid in estimating
@ -945,7 +945,7 @@ func (d *Downloader) fetchNodeData() error {
if err != nil {
// If the node data processing failed, the root hash is very wrong, abort
log.Error("State processing failed", "peer", packet.PeerId(), "err", err)
d.cancel()
d.Cancel()
return
}
// Processing succeeded, notify state fetcher of continuation
@ -1208,7 +1208,7 @@ func (d *Downloader) processHeaders(origin uint64, td *big.Int) error {
if atomic.LoadUint32(&d.fsPivotFails) == 0 {
for _, header := range rollback {
if header.Number.Uint64() == pivot {
log.Warn("Fast-sync critical section failure, locked pivot to header", "number", pivot, "hash", header.Hash())
log.Warn("Fast-sync pivot locked in", "number", pivot, "hash", header.Hash())
d.fsPivotLock = header
}
}

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@ -982,7 +982,7 @@ func testCancel(t *testing.T, protocol int, mode SyncMode) {
tester.newPeer("peer", protocol, hashes, headers, blocks, receipts)
// Make sure canceling works with a pristine downloader
tester.downloader.cancel()
tester.downloader.Cancel()
if !tester.downloader.queue.Idle() {
t.Errorf("download queue not idle")
}
@ -990,7 +990,7 @@ func testCancel(t *testing.T, protocol int, mode SyncMode) {
if err := tester.sync("peer", nil, mode); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
tester.downloader.cancel()
tester.downloader.Cancel()
if !tester.downloader.queue.Idle() {
t.Errorf("download queue not idle")
}

View File

@ -175,6 +175,14 @@ func (pm *ProtocolManager) synchronise(peer *peer) {
// Otherwise try to sync with the downloader
mode := downloader.FullSync
if atomic.LoadUint32(&pm.fastSync) == 1 {
// Fast sync was explicitly requested, and explicitly granted
mode = downloader.FastSync
} else if currentBlock.NumberU64() == 0 && pm.blockchain.CurrentFastBlock().NumberU64() > 0 {
// The database seems empty as the current block is the genesis. Yet the fast
// block is ahead, so fast sync was enabled for this node at a certain point.
// The only scenario where this can happen is if the user manually (or via a
// bad block) rolled back a fast sync node below the sync point. In this case
// however it's safe to reenable fast sync.
mode = downloader.FastSync
}
if err := pm.downloader.Synchronise(peer.id, pHead, pTd, mode); err != nil {

View File

@ -50,6 +50,7 @@ func (b *LesApiBackend) CurrentBlock() *types.Block {
}
func (b *LesApiBackend) SetHead(number uint64) {
b.eth.protocolManager.downloader.Cancel()
b.eth.blockchain.SetHead(number)
}