The Ethereum layer-two network Arbitrum has suffered its second outage in less than five months following a hardware failure.
Arbitrum is back online at the time of writing but the team did report some downtime during the late hours of Jan. 9. The timing of the tweets suggests that the network was down for around seven hours.
At the time, the Offchain Labs platform reported that it was experiencing some issues with the sequencer which prevented transactions from being processed for the period.
We are currently experiencing Sequencer downtime. Thank you for your patience as we work to restore it. All funds in the system are safe, and we will post updates here.
— Arbitrum (@arbitrum) January 9, 2022
On Jan. 10, Arbitrum released a post mortem explaining what had occurred to cause the brief outage. “The core issue was a hardware failure in our main Sequencer node,” it revealed, adding that backup Sequencer redundancies that would normally take control also failed due to an ongoing software update.
The network is designed to fall back to layer-one Ethereum to process transactions when it has its own Sequencer issues. However, it stated that efforts were made to make sure all transactions were confirmed by the Sequencer before going offline. A total of 284 transactions captured by the Sequencer were prevented from being posted to the Ethereum chain.
This was a very minor outage in the grand scheme of things but the team did remind users that the network is still essentially in beta.
“The Arbitrum network is still in beta, and we will keep this moniker as long as there are points of centralization that still exist in the system.”
The team concluded that it was working on further decentralizing the network with a “twofold path of minimizing Sequencer downtime” that will be deployed in the coming weeks and months.
In mid-September, Arbitrum suffered a similar Sequencer outage when a bug caused the system to get stuck after a large batch of transactions was executed over a short time frame.
Arbitrum is an Ethereum layer-two network using Optimistic rollups to batch transactions for faster and cheaper processing. It was launched as Arbitrum One in early September following a massive $120 million funding round.
According to layer-two data platform L2beat, Arbitrum is the most popular layer-two network at the moment with a total value locked of $2.57 billion giving it a L2 market share of 47%.