This Week's Global Internet Blackout Was Caused By A Single Customer, Says Fastly


Tom Hale

Senior Journalist

clockJun 9 2021, 17:44 UTC

It's unknown if the person knows how much power they wielded for one hour. Image credit: MikeDotta/

The global Internet crash that stopped some of the world’s most visited websites from working on Tuesday was caused by a single customer, according to the infrastructure provider Fastly.

At around 11 am BST (6 am EST / 3 am PST) on June 8, Internet users around the world were greeted with a message saying: “Error 503 service unavailable” and “connection failure.” A bunch of the world's most important and influential websites — including Twitch, Reddit, Amazon, Hulu, Spotify, and the UK government website, as well as media outlets such as the Financial Times, CNN, BBC, and the New York Times — had been plummeted into darkness.


The outage was caused by a problem at Fastly, a cloud computing services provider. All in all, the bug affected up to 85 percent of their network, affecting Internet users from Boston and Bogota to Tokyo and Toronto. Meanwhile, a bunch of others cities, such as Berlin and Beijing, remained unaffected.

Fastly managed to restore most of the network within an hour and apologized for the inconvenience. While investigating the problem, they found the widespread outage was caused by a single customer changing their settings, which triggered a dormant bug introduced in a May 2021 software update. It's unknown if this person knows what power they wielded for one hour.

“We experienced a global outage due to an undiscovered software bug that surfaced on June 8 when it was triggered by a valid customer configuration change,” Nick Rockwell, Senior Vice President of Engineering and Infrastructure at Fastly, said in a statement.


“Even though there were specific conditions that triggered this outage, we should have anticipated it,” Rockwell added 

It was undoubtedly a stressful day at the Fastly offices, but it wasn’t all bad news for the San Francisco-based company. Perhaps surprisingly, Fastly’s shares rose by 11 percent in the wake of the outage. The reasons behind the rise are multi-faceted, but it’s likely a reflection of how smoothly the problem was resolved. Furthermore, the outrage brought attention to how vital Fastly’s serves are to the day-to-day running of the internet infrastructure. I guess you don’t realize how much you need something until it’s gone…

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