Post-Mortem of Two Brief Base Mainnet Outages: Sequencer State Management Bug Causes Block Production Interruption

CoinFeed reported on June 27 that Base released a post-mortem report stating that the mainnet experienced two block production interruptions on June 25 and June 26, lasting approximately 116 minutes and 20 minutes respectively. The team emphasized that the incident did not affect on-chain asset security, and user funds remained available. The core cause of the failure was a flaw in the sequencer's block building logic: after a transaction execution failure, the system did not properly clear the historical journal state, leading to abnormal gas calculation during the execution of subsequent legitimate transactions, thereby generating invalid state transition blocks and halting block production across the entire L2 network. During the outage, issues included a complete halt of block production, inability for transactions to be included on-chain, and mempool congestion, with user-submitted eth_sendRawTransaction requests continuously returning errors.