Fix max fee per gas less than block base fee

[syntrust]

Addressing #284

Solution

Compute the gas price from the minimum profit and use it as the gas fee cap.

Tests been done

integration_tests/node_mine_test.go#TestMining() and node tests on L1 and L2 networks shows mining can be successfully done:

• using the minimum profitable gas price as gasFeeCap

# on Sepolia L1

INFO [10-08|14:51:18.449] Query baseFee done                       baseFee=3,304,814,517
INFO [10-08|14:51:18.852] Query gas tip cap done                   gasTipGap=1,216,647
INFO [10-08|14:51:18.852] Suggested gas fee cap                    gasFeeCap=3,306,031,164
INFO [10-08|14:51:19.257] Estimated gas done                       gas=401,601
INFO [10-08|14:51:19.620] Minimum profitable gas fee cap           gasFeeCap=7,470,186,602
INFO [10-08|14:51:19.620] Using profitable gas fee cap             gasFeeCap=7,470,186,602
INFO [10-08|14:51:20.443] Submit mined result done                 shard=0 block=6,836,741 nonce=330,091 txSigner=0x471977571aD818379E2b6CC37792a5EaC85FdE22 hash=0x1105769998ebeb7198f254cdb115492ff73ad993e545159887302e7b58024ab4
INFO [10-08|14:51:25.796] Mining transaction confirmed             txHash=110576..024ab4
INFO [10-08|14:51:26.896] "Mining transaction success!      √"     miner=0x471977571aD818379E2b6CC37792a5EaC85FdE22
INFO [10-08|14:51:26.896] Mining transaction details               txHash=110576..024ab4 gasUsed=393,068 effectiveGasPrice=3,203,772,189
INFO [10-08|14:51:26.896] Mining transaction accounting (in ether) reward=0.000000034 cost=0.001259300 profit=-0.001259266

# on L2 where gas prices are stable and baseFee is far less than tip

t=2024-09-29T15:31:37+0800 lvl=info msg="Query baseFee done"                  baseFee=252
t=2024-09-29T15:31:41+0800 lvl=dbug msg="Got latest block number by Randao querier" number=6,780,060
t=2024-09-29T15:31:41+0800 lvl=dbug msg="Fetching header by number by Randao querier" number=6,780,060
t=2024-09-29T15:31:41+0800 lvl=info msg="Query gas tip cap done"              gasTipGap=1,000,000
t=2024-09-29T15:31:41+0800 lvl=info msg="Suggested gas fee cap"               gasFeeCap=1,000,252
t=2024-09-29T15:31:45+0800 lvl=info msg="Estimated gas done"                  gas=394,411
t=2024-09-29T15:31:47+0800 lvl=info msg="Minimum profitable gas fee cap"      gasFeeCap=1,270,049
t=2024-09-29T15:31:47+0800 lvl=info msg="Using profitable gas fee cap"        gasFeeCap=1,270,049
t=2024-09-29T15:31:50+0800 lvl=dbug msg="Query nonce done"                    nonce=3215
t=2024-09-29T15:32:14+0800 lvl=info msg="Submit mined result done"            shard=59 block=6,780,053 nonce=146,956 txSigner=0x2F43878FAb122D9A7596949e4985cc284feCD4B8 hash=0xf340469b69b20682a505621c03669a039d659b1ffe9aee8556cf32cfb766ab30
t=2024-09-29T15:32:22+0800 lvl=info msg="Mining transaction confirmed"        txHash=0xf340469b69b20682a505621c03669a039d659b1ffe9aee8556cf32cfb766ab30
t=2024-09-29T15:32:24+0800 lvl=info msg="Mining transaction success!      √"  miner=0x534632D6d7aD1fe5f832951c97FDe73E4eFD9a77
t=2024-09-29T15:32:24+0800 lvl=info msg="Mining transaction details"          txHash=0xf340469b69b20682a505621c03669a039d659b1ffe9aee8556cf32cfb766ab30 gasUsed=385,949 effectiveGasPrice=1,000,252
t=2024-09-29T15:32:24+0800 lvl=info msg="Mining transaction accounting (in ether)" reward=0.000000001 cost=0.000000386 profit=-0.000000385

• drop the tx as baseFee + tip will not meet the minimum profit

# on Sepolia L1

NFO [10-08|13:45:59.239] Query baseFee done                       baseFee=1,441,982
INFO [10-08|13:45:59.543] Query gas tip cap done                   gasTipGap=1,374,798
INFO [10-08|13:45:59.543] Suggested gas fee cap                    gasFeeCap=2,816,780
INFO [10-08|13:45:59.868] Estimated gas done                       gas=401,042
INFO [10-08|13:46:00.172] Minimum profitable gas fee cap           gasFeeCap=47988
WARN [10-08|13:46:00.175] Mining tx dropped: the profit will not meet expectation estimatedProfit=-1,110,401,633,427 minimumProfit=0.000000000


# on L2

t=2024-09-29T15:26:46+0800 lvl=info msg="Query baseFee done"                  baseFee=252
t=2024-09-29T15:26:48+0800 lvl=info msg="Query gas tip cap done"              gasTipGap=1,000,000
t=2024-09-29T15:26:48+0800 lvl=info msg="Suggested gas fee cap"               gasFeeCap=1,000,252
t=2024-09-29T15:26:52+0800 lvl=info msg="Estimated gas done"                  gas=533,292
t=2024-09-29T15:28:32+0800 lvl=info msg="Minimum profitable gas fee cap"      gasFeeCap=991,580
t=2024-09-29T15:28:32+0800 lvl=warn msg="Mining tx dropped: the profit will not meet expectation" estimatedProfit=-0.000000505 minimumProfit=-0.000000500