minimal-gas-prices and baseFeePerGas conflicts

[yihuang]

Currently, when the feemarket module is enabled, for eth transactions we have an extra requirement:

effectiveGasPrice >= minimal-gas-prices
where effectiveGasPrice = min(baseFeePerGas + tipCap, feeCap) for `DynamicFeeTx`
      effectiveGasPrice = gasPrice for `LegacyTx`

Usually, clients pick zero or constant tipCap for dynamic fee tx, and baseFeePerGas keep dropping when blocks are sparse, when baseFeePerGas drop to a point where effectiveGasPrice < minimal-gas-prices, the dynamic fee tx will fail, and client have to re-calculate a tipCap based on current minimal-gas-prices and baseFeePerGas. So basically the client logic will be different from go-ethereum.

A simple solution is don't check minimal-gas-prices at all for eth tx when feemarket is enabled. And for legacy tx, rather than check tx.gasPrice >= minimal-gas-prices, we check tx.gasPrice >= baseFeePerGas.

And considering the native cosmos tx, we shouldn't set min-gas-price too low, a reasonable one might be set min-gas-price = initial base fee.

[thomas-nguy]

isnt tipCap = minimal-gas-prices?

in that case effectiveGasPrice can never be inferior to minimal-gas-price?

(in case feecap is lower, then its normal for tx to fail)

[yihuang]

That'll cost minimal-gas-prices + baseFeePerGas for dynamic fee tx, while only cost minimal-gas-prices for legacy tx.

[thomas-nguy]

yeah i see, for legacy tx, if feemarket module is enable, it would be more sense to check baseFee instead of min-gas-price

[thomas-nguy]

btw what do you mean by legacy tx?

I think we dont make the distinction on ante handler between legacy and dynamic tx and both txs should follow the same rule

• if feemarket enable then check that txfee >= baseFee + min-gas-price
• if feemarket not enable then check that txFee >= min-gas-price

txFee = effectiveFee for dynamicTx (EIP 1559) or = gasprice for legacytx

[yihuang]

For DynamicFeeTx, effectiveGasPrice is min(baseFeePerGas + tipCap, feeCap).
For LegacyTx, effectiveGasPrice is gasPrice.

[yihuang]

Currently, the eth_gasPrice API returns baseFeePerGas + minimal-gas-price, I think that's wrong too.

[robert-zaremba]

In your model, is minimal-gas-price part of consensus or a block producer parameter?

[yihuang]

In your model, is minimal-gas-price part of consensus or a block producer parameter?

block producer parameter, what we have in cosmos-sdk currently.