Bug in Sequencer Causes Arbitrum Blockchain to Temporarily Halt Processing Transactions
A bug in the sequencer of Layer 2 blockchain Arbitrum caused a temporary pause in transaction processing on Wednesday. The ecosystem, which has a total value locked of $2.21 billion, was impacted by this interruption. The function of Arbitrum’s sequencer is to package user transactions and subsequently publish them on the blockchain. A technical glitch arose while attempting to publish the transactions, leading to their reversal and consequent disruption of network operations.
The developers of Arbitrum took to Twitter to provide an update on the matter, clarifying that the issue only caused a brief halt in the process of finalizing transaction ordering on the blockchain. This did not result in any major disruption to the Sequencer’s overall functionality. The individuals in charge refuted allegations of the sequencer running out of funds and instead affirmed that the system underwent testing and operated according to its design. At the time, the developers did not furnish specific details regarding the glitch. They did, however, indicate that a comprehensive post-mortem report would be made available subsequently.
As per a report by DL News, the on-chain data suggests that the sequencer has exhausted its ether reserves, resulting in complications in transaction processing. The developers of Arbitrum have provided clarification that the aforementioned fail-safe mechanism was intentionally implemented. The sequencer utilizes a dual wallet system, wherein the primary sequencer wallet maintains a modest ether balance that is automatically restocked by a secondary wallet referred to as the “gas-refunder” wallet, which contains a higher ether balance. According to the developers, the gas-refunder wallet replenishes the sequencer wallet upon the completion of a successful batch processing. In case of a sequencer malfunction, there will be no provision for refill or refund. According to DL News, it was observed that a wallet was utilized to manually replenish the gas fees of the sequencer, which facilitated the resumption of transaction processing.
To summarize, there was a bug in the batch-poster that caused it not to post transactions on-chain for some period of time.
A full post-mortem describing the bug will follow shortly and we are glad the fail-safe system worked as intended during the incident!
— Arbitrum Developers (💙,🧡) (@ArbitrumDevs) June 7, 2023
The developers have highlighted that the malfunction was not a result of the sequencer running out of funds. Additionally, they have stated that the Arbitrum network did not provide any refund to the Sequencer for this matter. It was confirmed that the fail-safe mechanism had functioned as designed. At present, Arbitrum has recommenced the processing of transactions, while its indigenous token ARB is being traded at $1.13, indicating a decline of 2% in its value during the last 24 hours.