Optimism outage unrelated to scheduled maintenance

The Optimism Mainnet underwent an hour of maintenance, but went down prematurely earlier today for 2 hours

article-image

CryptoFX/Shutterstock modified by Blockworks

share

The Optimism Mainnet blockchain experienced a series of outages and instabilities on Feb. 15, 2024, beginning around 6:00 am ET. The team started investigating reports of an “unsafe head stall,” meaning the sequencer stopped producing blocks.

Shortly after at 6:10 am ET, developers identified the cause of the issue and applied a fix that briefly restored operations.

However, the resolution was short-lived; by 6:26 am ET, reports of additional instability called into question the efficacy of the patch, according to the network’s status page.

The Optimism sequencer remains centralized, meaning OP Labs is responsible for identifying and troubleshooting problems.

Read more: Optimism devs tackle bad actors with fault-proof system testnet launch

After finding the suspected root cause, the network resumed around 8:00 am ET when the status page noted the incident was unrelated to the planned pause of OP Mainnet withdrawals — a scheduled maintenance window began at 9:01 am ET and ended one hour later.

Loading Tweet..

Blockworks has contacted Optimism for details.

Arbitrum, the largest Ethereum rollup by total value locked (TVL), suffered a similar outage in December 2023.

Read more: Arbitrum suffers ‘partial outage’ amid traffic influx

Although the team stated that no action was required from users or node operators following the resolution, community members in Discord dispute that.

“I can also confirm that a full node restart of op-node and op-geth was required to get unstuck,” wrote one member hazim-j.eth, co-founder of Stackup, who works on account abstraction tooling.

“If the status page had advised a restart we might have been able to get back online a lot sooner,” he said.  

During the outage, node operators observed single-block reorganizations — or reorg — of the unsafe chain.

A single-block reorg, not uncommon in blockchain operations, occurs when the chain diverges into two paths due to discrepancies in block validation and then reconverges on a single, agreed-upon path.

In the case of Optimism, an “unsafe” head reorg refers to blocks produced by the sequencer, but not yet posted in batches to Ethereum mainnet, according to pseudonymous developer support engineer at OP Labs known as Soyboy Vegan.

According to Optimism’s documentation, “it is still possible for [unsafe transactions] to be excluded from the final blockchain if the Sequencer fails to publish the block to Ethereum in a timely manner.”

The planned withdrawal pause scheduled for 9:00 to 10:00 am ET was intended to “test Optimism’s incident response capabilities,” according to an OP Labs X post.

Updated on Feb. 15, 2024, at 11:05 am ET, with additional context.


Get the news in your inbox. Explore Blockworks newsletters:

Tags

Decoding crypto and the markets. Daily, with Byron Gilliam.

Upcoming Events

Javits Center North | 445 11th Ave

Tues - Thurs, March 24 - 26, 2026

Blockworks’ Digital Asset Summit (DAS) will feature conversations between the builders, allocators, and legislators who will shape the trajectory of the digital asset ecosystem in the US and abroad.

recent research

Unlocked by Template.png

Research

The march toward an interoperable and onchain-by-default internet depends on reliable messaging and value transfer across heterogeneous domains. Crosschain protocols now process >$1.3T in combined annual transfer volume and secure tens of millions of user interactions, yet no single design dominates.

article-image

The goal, per Santiago Santos, is to make crypto a relatable piece of tech for people who may not even understand it

article-image

Stripe stablecoin unit aims to operate under a federal charter enabling regulated stablecoin issuance and custody services

by Blockworks /
article-image

Will TradFi make crypto better or create more problems than it solves?

article-image

Subtle decisions by risk curators saved Aave from significant turmoil

article-image

The new Rootstock Institutional unit aims to connect professional investors to Bitcoin-native yield and liquidity strategies anchored in BTC’s security layer

by Blockworks /
article-image

DOJ files record civil forfeiture against more than 127,000 BTC linked to scam activity

by Blockworks /