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author | Antoine Riard <ariard@student.42.fr> | 2020-09-04 14:33:00 -0400 |
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committer | Antoine Riard <ariard@student.42.fr> | 2020-09-10 09:51:03 -0400 |
commit | d76925478efd35e6fd835370639f2139b28381e4 (patch) | |
tree | aa395e9f2ce171a1c51af15659f4a9c4f579c6a4 | |
parent | ac71fe936da290adf5a3155fe8db5f78b485f1f1 (diff) | |
download | bitcoin-d76925478efd35e6fd835370639f2139b28381e4.tar.xz |
[doc] Clarify semantic of peer's m_protect w.r.t to outbound eviction logics
The field m_protect is used to protect from eviction both by bad/lagging
chain and extra outbound peers logics. Outbound block-relay peers are
always excluded from this protection.
-rw-r--r-- | src/net_processing.cpp | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/src/net_processing.cpp b/src/net_processing.cpp index 6762a94a6f..37eed95b60 100644 --- a/src/net_processing.cpp +++ b/src/net_processing.cpp @@ -321,10 +321,17 @@ struct CNodeState { */ bool fSupportsDesiredCmpctVersion; - /** State used to enforce CHAIN_SYNC_TIMEOUT - * Only in effect for outbound, non-manual, full-relay connections, with - * m_protect == false - * Algorithm: if a peer's best known block has less work than our tip, + /** State used to enforce CHAIN_SYNC_TIMEOUT and EXTRA_PEER_CHECK_INTERVAL logic. + * + * Both are only in effect for outbound, non-manual, non-protected connections. + * Any peer protected (m_protect = true) is not chosen for eviction. A peer is + * marked as protected if all of these are true: + * - its connection type is IsBlockOnlyConn() == false + * - it gave us a valid connecting header + * - we haven't reached MAX_OUTBOUND_PEERS_TO_PROTECT_FROM_DISCONNECT yet + * - it has a better chain than we have + * + * CHAIN_SYNC_TIMEOUT: if a peer's best known block has less work than our tip, * set a timeout CHAIN_SYNC_TIMEOUT seconds in the future: * - If at timeout their best known block now has more work than our tip * when the timeout was set, then either reset the timeout or clear it @@ -334,6 +341,9 @@ struct CNodeState { * and set a shorter timeout, HEADERS_RESPONSE_TIME seconds in future. * If their best known block is still behind when that new timeout is * reached, disconnect. + * + * EXTRA_PEER_CHECK_INTERVAL: after each interval, if we have too many outbound peers, + * drop the outbound one that least recently announced us a new block. */ struct ChainSyncTimeoutState { //! A timeout used for checking whether our peer has sufficiently synced |