An outage at Fastly, a cloud-based content platform that serves many leading international websites, sent large chunks of the Web offline on Tuesday.

Fastly is one of a number of high-level website and application hosting services that large enterprises use to serve content to millions of users simultaneously.

Rather than hosting all website content on a single set of servers in one location, Fastly puts cloud infrastructure in dozens of locations to let people download from a server closest to them.

Similar to Amazon Web Services, Cloudflare and Microsoft’s Azure, Fastly is designed to resist outages caused by a range of network issues. These range from congestion and localised power failures to the distributed denial-of-service attacks often used by hackers to overwhelm a website.

By using multiple machines to host the same content, Fastly attempts to make it extremely hard to push a company’s web presence offline.

Problems

Major websites began reporting problems around 11:30am South African time on Tuesday, according to Downdetector.

Fastly acknowledged the issue at 11:58am, saying: “We’re currently investigating potential impact to performance with our CDN services.” At 12.44pm, the company said it had identified the problem and was implementing a fix. The company pared losses in premarket trading after a fall of more than 7% during the outage.

Websites hit by the outage, including Amazon.com, the New York Times, Reddit and UK government sites were accessible again shortly afterward.

There are many similarities between this outage and an issue with Cloudflare last year. Cloudflare’s problems arose because — in simple terms — the company’s engineers tried to reroute Internet traffic and everything exploded.

Both companies route website traffic through their servers. So when their servers break, so does everything else. These problems are also hard to prevent, and often happen when companies need to update their systems.

There is no evidence to suggest Fastly’s issues on Tuesday were the result of a malicious cyberattack. By contrast, all website system administrators know that network outages and downtime can happen, no matter the size of their hosting platform.

As such, a single outage in a year for under 60 minutes isn’t usually enough to warrant moving to a rival provider.

Depending on the service level agreement signed between it and affected customers, however, Fastly may offer refunds or credits equivalent to the number of minutes a website was unavailable, according to its website.

Widespread outages are often the result of hackers, but not always the fault of the companies hosting content. For instance, in 2016, millions of Internet users lost access to some of the world’s most popular websites after hackers compromised domain name system service provider Dyn. That knocked offline sites including Twitter, Spotify, Reddit, CNN, Etsy and the New York Times. — Reported by Nate Lanxon, (c) 2021 Bloomberg LP