net_processing: Boost inv trickle rate

ajtowns · fanquake · commit 128da6e41fc2 · 2023-05-11T14:24:19.000+01:00
If transactions are being added to the mempool at a rate faster than 7tx/s (INVENTORY_BROADCAST_PER_SECOND) then peers' inventory_to_send queue can become relatively large. If this happens, increase the number of txids we include in an INV message (normally capped at 35) by 5 for each 1000 txids in the queue. This will tend to clear a temporary excess out reasonably quickly; an excess of 4000 invs to send will be cleared down to 1000 in about 30 minutes, while an excess of 20000 invs would be cleared down to 1000 in about 60 minutes. Github-Pull: #27610 Rebased-From: 5b34060
diff --git a/src/net_processing.cpp b/src/net_processing.cpp
@@ -5594,7 +5594,9 @@ bool PeerManagerImpl::SendMessages(CNode* pto)
                     // especially since we have many peers and some will draw much shorter delays.
                     unsigned int nRelayedTransactions = 0;
                     LOCK(tx_relay->m_bloom_filter_mutex);
-                    while (!vInvTx.empty() && nRelayedTransactions < INVENTORY_BROADCAST_MAX) {
+                    size_t broadcast_max{INVENTORY_BROADCAST_MAX + (tx_relay->m_tx_inventory_to_send.size()/1000)*5};
+                    broadcast_max = std::min<size_t>(1000, broadcast_max);
+                    while (!vInvTx.empty() && nRelayedTransactions < broadcast_max) {
                         // Fetch the top element from the heap
                         std::pop_heap(vInvTx.begin(), vInvTx.end(), compareInvMempoolOrder);
                         std::set<uint256>::iterator it = vInvTx.back();
