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:

  • Blockworks Daily: The newsletter that helps thousands of investors understand crypto and the markets, by Byron Gilliam.
  • Empire: Start your morning with the top news and analysis to inform your day in crypto.
  • Forward Guidance: Reporting and analysis on the growing intersection of crypto and macroeconomics, policy and finance.
  • 0xResearch: Alpha directly in your inbox. Market highlights, data, degen trade ideas, governance updates, token performance and more.
  • Lightspeed: Built for Solana investors, developers and community members. The latest from one of crypto’s hottest networks.
  • The Drop: For crypto collectors and traders, covering apps, games, memes and more.
  • Supply Shock: Tracking Bitcoin’s rise from internet plaything worth less than a penny to global phenomenon disrupting money as we know it.
Tags

Upcoming Events

Industry City | Brooklyn, NY

TUES - THURS, JUNE 24 - 26, 2025

Permissionless IV serves as the definitive gathering for crypto’s technical founders, developers, and builders to come together and create the future.If you’re ready to shape the future of crypto, Permissionless IV is where it happens.

Old Billingsgate

Mon - Wed, October 13 - 15, 2025

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

Research

article-image

With much of the bitcoin mining supply chain based in Asia, US-based operations now face higher equipment prices

article-image

Anticipating an economic downturn, venture firms may be less likely to invest

article-image

Trump’s tariffs may have potentially significant impacts on GDP, household spending and food prices — if they hold

article-image

The Binance-affiliated stablecoin lost about $200M of market capitalization

article-image

How the Bitcoin conversation has evolved since the price was less than $1

article-image

The platform also rolled out 13 tokenized funds for institutions on the Connect platform