highperfocused/bitcoin
1
0
Fork 0
mirror of https://github.com/bitcoin/bitcoin.git synced 2026-05-05 19:38:54 +02:00
Code Issues Packages Projects Releases Wiki Activity

[policy] lower default minrelaytxfee and incrementalrelayfee to 100sat/kvB

Browse Source 
Let's say an attacker wants to use/exhaust the network's bandwidth, and
has the choice between renting resources from a commercial provider and
getting the network to "spam" itself it by sending unconfirmed
transactions. We'd like the latter to be more expensive than the former.

The bandwidth for relaying a transaction across the network is roughly
its serialized size (plus relay overhead) x number of nodes. A 1000vB
transaction is 1000-4000B serialized. With 100k nodes, that's 0.1-0.4GB
If the going rate for commercial services is 10c/GB, that's like 1-4c per kvB
of transaction data, so a 1000vB transaction should pay at least $0.04.

At a price of 120k USD/BTC, 100sat is about $0.12. This price allows us
to tolerate a large decrease in the conversion rate or increase in the
number of nodes.
This commit is contained in:
glozow
2025-07-29 14:37:16 -04:00
parent 2e515d2897
commit 6da5de58ca
12 changed files with 49 additions and 47 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
test/functional/mempool_limit.py
View File

@@ -206,7 +206,7 @@ class MempoolLimitTest(BitcoinTestFramework):
# coin is no longer available, but the cache could still contain the tx.
cpfp_parent = self.wallet.create_self_transfer(
utxo_to_spend=replaced_tx["new_utxo"],
fee_rate=mempoolmin_feerate - Decimal('0.00001'),
fee_rate=mempoolmin_feerate - Decimal('0.000001'),
confirmed_only=True)
self.wallet.rescan_utxos()
@@ -312,9 +312,9 @@ class MempoolLimitTest(BitcoinTestFramework):
target_vsize_each = 50000
assert_greater_than(target_vsize_each * 2 * 3, node.getmempoolinfo()["maxmempool"] - node.getmempoolinfo()["bytes"])
# Should be a true CPFP: parent's feerate is just below mempool min feerate
parent_feerate = mempoolmin_feerate - Decimal("0.000001") # 0.1 sats/vbyte below min feerate
parent_feerate = mempoolmin_feerate - Decimal("0.0000001") # 0.01 sats/vbyte below min feerate
# Parent + child is above mempool minimum feerate
child_feerate = (worst_feerate_btcvb * 1000) - Decimal("0.000001") # 0.1 sats/vbyte below worst feerate
child_feerate = (worst_feerate_btcvb * 1000) - Decimal("0.0000001") # 0.01 sats/vbyte below worst feerate
# However, when eviction is triggered, these transactions should be at the bottom.
# This assertion assumes parent and child are the same size.
miniwallet.rescan_utxos()