Merge #10345: [P2P] Timeout for headers sync

76f7481 Add timeout for headers sync (Suhas Daftuar)
e265200 Delay parallel block download until chain has sufficient work (Suhas Daftuar)

Tree-SHA512: e7f5468b7defe67d4d2d5c976bc129dba2b32b2ea52d3ff33b9cbff5c3b5b799be867653f1bcd354340d707d76dcadf2da4588abf6d6ec4a06672cdc5e1101eb
This commit is contained in:
Wladimir J. van der Laan 2017-06-06 12:14:21 +02:00
commit 67700b3924
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2 changed files with 42 additions and 1 deletions

View file

@ -168,6 +168,8 @@ struct CNodeState {
int nUnconnectingHeaders;
//! Whether we've started headers synchronization with this peer.
bool fSyncStarted;
//! When to potentially disconnect peer for stalling headers download
int64_t nHeadersSyncTimeout;
//! Since when we're stalling block download progress (in microseconds), or 0.
int64_t nStallingSince;
std::list<QueuedBlock> vBlocksInFlight;
@ -207,6 +209,7 @@ struct CNodeState {
pindexBestHeaderSent = NULL;
nUnconnectingHeaders = 0;
fSyncStarted = false;
nHeadersSyncTimeout = 0;
nStallingSince = 0;
nDownloadingSince = 0;
nBlocksInFlight = 0;
@ -481,7 +484,7 @@ void FindNextBlocksToDownload(NodeId nodeid, unsigned int count, std::vector<con
// Make sure pindexBestKnownBlock is up to date, we'll need it.
ProcessBlockAvailability(nodeid);
if (state->pindexBestKnownBlock == NULL || state->pindexBestKnownBlock->nChainWork < chainActive.Tip()->nChainWork) {
if (state->pindexBestKnownBlock == NULL || state->pindexBestKnownBlock->nChainWork < chainActive.Tip()->nChainWork || state->pindexBestKnownBlock->nChainWork < UintToArith256(consensusParams.nMinimumChainWork)) {
// This peer has nothing interesting.
return;
}
@ -2881,6 +2884,7 @@ bool SendMessages(CNode* pto, CConnman& connman, const std::atomic<bool>& interr
// Only actively request headers from a single peer, unless we're close to today.
if ((nSyncStarted == 0 && fFetch) || pindexBestHeader->GetBlockTime() > GetAdjustedTime() - 24 * 60 * 60) {
state.fSyncStarted = true;
state.nHeadersSyncTimeout = GetTimeMicros() + HEADERS_DOWNLOAD_TIMEOUT_BASE + HEADERS_DOWNLOAD_TIMEOUT_PER_HEADER * (GetAdjustedTime() - pindexBestHeader->GetBlockTime())/(consensusParams.nPowTargetSpacing);
nSyncStarted++;
const CBlockIndex *pindexStart = pindexBestHeader;
/* If possible, start at the block preceding the currently
@ -3204,6 +3208,39 @@ bool SendMessages(CNode* pto, CConnman& connman, const std::atomic<bool>& interr
return true;
}
}
// Check for headers sync timeouts
if (state.fSyncStarted && state.nHeadersSyncTimeout < std::numeric_limits<int64_t>::max()) {
// Detect whether this is a stalling initial-headers-sync peer
if (pindexBestHeader->GetBlockTime() <= GetAdjustedTime() - 24*60*60) {
if (nNow > state.nHeadersSyncTimeout && nSyncStarted == 1 && (nPreferredDownload - state.fPreferredDownload >= 1)) {
// Disconnect a (non-whitelisted) peer if it is our only sync peer,
// and we have others we could be using instead.
// Note: If all our peers are inbound, then we won't
// disconnect our sync peer for stalling; we have bigger
// problems if we can't get any outbound peers.
if (!pto->fWhitelisted) {
LogPrintf("Timeout downloading headers from peer=%d, disconnecting\n", pto->GetId());
pto->fDisconnect = true;
return true;
} else {
LogPrintf("Timeout downloading headers from whitelisted peer=%d, not disconnecting\n", pto->GetId());
// Reset the headers sync state so that we have a
// chance to try downloading from a different peer.
// Note: this will also result in at least one more
// getheaders message to be sent to
// this peer (eventually).
state.fSyncStarted = false;
nSyncStarted--;
state.nHeadersSyncTimeout = 0;
}
}
} else {
// After we've caught up once, reset the timeout so we can't trigger
// disconnect later.
state.nHeadersSyncTimeout = std::numeric_limits<int64_t>::max();
}
}
//
// Message: getdata (blocks)

View file

@ -17,6 +17,10 @@ static const int64_t ORPHAN_TX_EXPIRE_TIME = 20 * 60;
static const int64_t ORPHAN_TX_EXPIRE_INTERVAL = 5 * 60;
/** Default number of orphan+recently-replaced txn to keep around for block reconstruction */
static const unsigned int DEFAULT_BLOCK_RECONSTRUCTION_EXTRA_TXN = 100;
/** Headers download timeout expressed in microseconds
* Timeout = base + per_header * (expected number of headers) */
static constexpr int64_t HEADERS_DOWNLOAD_TIMEOUT_BASE = 15 * 60 * 1000000; // 15 minutes
static constexpr int64_t HEADERS_DOWNLOAD_TIMEOUT_PER_HEADER = 1000; // 1ms/header
/** Register with a network node to receive its signals */
void RegisterNodeSignals(CNodeSignals& nodeSignals);