tx fee issue

[saltedlolly]

As documented by James from CoinMinerz on 26th October on the DigiByte Discord:

"Another thing we need to address is tx fee bug to make sure anyone using RC2 or RC3 on mainnet doesn't have the mempool issue we've seen on coinminerz when payments go out. What happens is the tx fee is too low in the code and when sent it sits in mempool as it's a cheaper tx fee."

https://discord.com/channels/878200503815782400/1117868419283423293/1166363365061431417

[JaredTate]

Thanks for bringing this issue up. We increased DEFAULT_MIN_RELAY_TX_FEE but it appears we likely need to also increase DEFAULT_BLOCK_MIN_TX_FEE & maybe DEFAULT_INCREMENTAL_RELAY_FEE & DUST_RELAY_TX_FEE.

digibyte/src/validation.h

Line 73 in b75fea6

static const unsigned int DEFAULT_MIN_RELAY_TX_FEE = 100000;

digibyte/src/policy/policy.h

Line 25 in b75fea6

static const unsigned int DEFAULT_BLOCK_MIN_TX_FEE = 1000;

It looks like DEFAULT_BLOCK_MIN_TX_FEE is called in BlockAssembler, so its being assembled with lower fees, then getting rejected by PeerManagerImpl::MaybeSendFeefilter where DEFAULT_MIN_RELAY_TX_FEE is called.

digibyte/src/miner.cpp

Lines 56 to 59 in b75fea6

	BlockAssembler::Options::Options() {
	blockMinFeeRate = CFeeRate(DEFAULT_BLOCK_MIN_TX_FEE);
	nBlockMaxWeight = DEFAULT_BLOCK_MAX_WEIGHT;
	}

PeerManagerImpl::MaybeSendFeefilter calls DEFAULT_MIN_RELAY_TX_FEE and filters out TXs without high enough fees, that's why they sit in mempool. Block assembler not including high enough fee.

digibyte/src/net_processing.cpp

Lines 4528 to 4539 in b75fea6

	void PeerManagerImpl::MaybeSendFeefilter(CNode& pto, std::chrono::microseconds current_time)
	{
	AssertLockHeld(cs_main);
	if (m_ignore_incoming_txs) return;
	if (!pto.m_tx_relay) return;
	if (pto.GetCommonVersion() < FEEFILTER_VERSION) return;
	// peers with the forcerelay permission should not filter txs to us
	if (pto.HasPermission(NetPermissionFlags::ForceRelay)) return;
	CAmount currentFilter = m_mempool.GetMinFee(gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000).GetFeePerK();
	static FeeFilterRounder g_filter_rounder{CFeeRate{DEFAULT_MIN_RELAY_TX_FEE}};

We should probably update these below too:

digibyte/src/policy/policy.h

Line 37 in b75fea6

static const unsigned int DEFAULT_INCREMENTAL_RELAY_FEE = 1000;

digibyte/src/policy/policy.h

Line 57 in b75fea6

static const unsigned int DUST_RELAY_TX_FEE = 3000;

[ycagel]

This issue is resolved as #151 and #157 have been merged.