From 3d7c30ebb6ac0c586635c693a40bc39180f539b9 Mon Sep 17 00:00:00 2001 From: bitflash-maintainer Date: Tue, 11 Aug 2026 20:52:09 +0000 Subject: pool: refuse jobs when no peer has reported a height for 20 minutes The peer-height gate replaced a tip-age check that was wrong in both directions. It is a strict improvement and it is still blind in the one case that matters most. When the node goes deaf -- peers still in vNodes, nothing arriving -- no peer announces anything, GetPeerMedianHeight() returns -1, and the fallback mines our best chain. That fallback is right for a node that has not been told yet and wrong for a node that has stopped being able to hear, and a height nobody sent cannot tell those apart. A wedged node is exactly a node with no peer height information, so the gate was silent for the whole of heights 3966-4085: 120 blocks, 5890.50 BTF voided. Time can tell them apart. GetPeerHeightAgeSecs() measures how long since any peer reported a height, counting from first use rather than the epoch so a starting node does not refuse jobs before its first handshake. Past 20 minutes the pool stops issuing jobs and says so unconditionally in the log. /poolmineblind overrides it: without an escape hatch a genuinely isolated pool that is 90% of the hashrate could never restart its own chain, which is the deadlock the tip-age check used to cause. Also stop nStartingHeight from going stale. It was a snapshot taken once during the version handshake and never touched again, so on a long-lived connection the median is built from heights the peers had hours ago, and the behind-the-network check drifts toward 'everyone is behind us' and quietly stops firing. A peer that hands us a block is demonstrably at least at that block's height. (cherry picked from commit 0800c18faf703b4acde1b131d0b742d37a86d92b) --- src/main.cpp | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'src/main.cpp') diff --git a/src/main.cpp b/src/main.cpp index 382a008..5d0b70a 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -88,6 +88,7 @@ string strSetDataDir; int nDropMessagesTest = 0; bool fSoloMineTest = false; // /solomine: mine without requiring a peer (local test) bool fPoolNoAnnounce = false; // /noannounce: operator serves miners but never publishes pool announcements +bool fPoolMineBlind = false; // /poolmineblind: issue jobs even when no peer has reported a height // Settings int fGenerateBitcoins; @@ -3172,7 +3173,21 @@ bool ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv) pfrom->AddInventoryKnown(inv); if (ProcessBlock(pfrom, pblock.release())) + { mapAlreadyAskedFor.erase(inv); + + // A peer that just handed us a block is demonstrably at least at + // that block's height. Without this, nStartingHeight is a snapshot + // taken once during the version handshake and never touched again, + // so on a long-lived connection it is the peer's height from + // however many hours ago it happened to connect. The pool's + // behind-the-network check compares against the median of those + // numbers, so as connections age it drifts toward "everyone is + // behind us" and quietly stops firing -- the opposite of its job. + map::iterator mi = mapBlockIndex.find(inv.hash); + if (mi != mapBlockIndex.end() && mi->second) + pfrom->nStartingHeight = max(pfrom->nStartingHeight, mi->second->nHeight); + } } -- cgit v1.2.3