Metamask keeps failing sending transactions

[thomas-nguy]

The problem comes from the feemarket base fee.

Metamask does not add any buffer and uses the base fee specified in the block.

Since the average block time is quite fast (few sec), the base fee might increase when it tries to execute it, it fails the transaction.

Solution: Either reintroduce a configurable tip or add a buffer in rpc gas-price endpoints (maybe add 2~5 times the maximum base fee variation)

[yihuang]

baseFeeDelta = parentBaseFee * (parentGasUsed - parentGasTarget) / parentGasTarget / baseFeeChangeDenominator

To get a maximum of baseFeeDelta, we set:

parentGasTarget = gasLimit / ElasticityMultiplier
parentGasUsed = gasLimit

Then max baseFeeDelta for next block is:

baseFeeDelta = parentBaseFee * (ElasticityMultiplier - 1) / baseFeeChangeDenominator

Multiply that with 5 should give us a good heuristic default value?

[yihuang]

I think maybe that's too much, after all, user will need to pay those tip fees, so I suggest baseFee / 8 should be enough to cover most of cases

[thomas-nguy]

hmmm basefee/8 might be too much? its more than 10% more expensive.

I still think that using baseFeeDelta might be better. Since the delta change happens every few seconds it should be less

[yihuang]

hmmm basefee/8 might be too much? its more than 10% more expensive.

I still think that using baseFeeDelta might be better. Since the delta change happens every few seconds it should be less

baseFeeDelta = parentBaseFee * (ElasticityMultiplier - 1) / baseFeeChangeDenominator

assume ElasticityMultiplier and denominator are the default value 2 and 8, the max delta for one block will be 1/8 * parentBaseFee for one block.
Maybe better to change the 1/8 to the configured values rather than constant though.

[yihuang]

I think in ethereum if gas price is not enough, it'll be kept in a future list rather than rejected immediately, which provides better UX than us, not sure if that's possible in the future with abci++.