Tuesday 8 June 2021 1:13 pm

Internet outage: What is Fastly and how can a glitch bring down the world’s biggest websites?

The internet was plunged into a temporary blackout this morning as thousands of websites were hit by a global outage.

Some of the world’s biggest news sites, including the BBC, Guardian and Financial Times, were hit by the glitch, as well as streaming service Spotify, ecommerce giant Amazon social media platform Reddit and even the UK government website.

But what happened, and how can so many of the world’s largest sites go down at once?

What happened?

Thousands of websites were inaccessible for roughly an hour this morning. Visitors to the affected sites were shown a 503 error, meaning their browser was unable to access the server of the destination site.

What was behind the outage?

The outage is believed to be linked to a glitch at Fastly, a US-based cloud computing company. Earlier this morning most of its coverage areas were suffering “degraded performance”, according to the company’s website.

In a statement after sites came back online, Fastly said: “The issue has been identified and a fix has been applied. Customers may experience increased origin load as global services return.”

What is Fastly?

Silicon Valley-based Fastly operates a content delivery network (CDN) — a group of servers spread across different geographical locations.

CDNs provide faster loading times for web pages, as well as for larger files including images and videos.

They do this through so-called edge cloud computing, where data is brought away from the main, centralised cloud servers and closer to the devices that are trying to access it. 

Why did so many sites go down?

The scale of the outage is due simply to Fastly’s position as one of the world’s largest CDN providers. It counts scores of media outlets, online retailers and financial services platforms among its clients. So when Fastly suffered an outage, all of these sites were affected.

Should we be worried?

While Fastly quickly resolved the issue, and access to the impacted websites has been restored, the incident has sparked concerns about the internet’s reliance on just a few major cloud providers.

“This is what happens when half of the internet relies on goliaths like Amazon, Google and Fastly for all of its servers and web services,” says Gaz Jones, technical director of digital agency Think3. “The entire internet has become dangerously geared on just a few players.”

Michael Barragry, operations lead and security consultant at cyber firm Edgescan, adds: “This outage could also represent a window of opportunity for further attacks — especially against those sites which have an over-dependence upon CDN infrastructure for their security. 

“Additional independent security layers should be used where appropriate to ensure that no single point of failure is present.”