More than 30,000 websites for travel, banking, news, e-commerce and international shipping companies experienced an outage on Thursday.
Among the affected sites were those of Airbnb, Amazon, American Express, Costco, Delta Air Lines, Home Depot, McDonald's and UPS.
Streaming services run by HBO, gaming sites run by Microsoft, public transit sites like the New York subway and bus system, and financial service companies like Capital One were also hit by the outage.
“We have implemented a fix for this issue, and based on current observations, the service is resuming normal operations,” the company Akamai, which provides Domain Name System (DNS) services to thousands of companies, said in a tweet.
The outage only lasted for about an hour, but concern spread across social media as the event was similar to another outage that occurred in recent months.
What is Akamai?
Akamai is a cloud-based company based in Cambridge, Massachusetts, that handles web content delivery globally.
As a content delivery network (CDN), it ensures the availability and performance of thousands of websites.
Companies hire the services of businesses like Akamai to make their websites run reliably and smoothly for users around the world.
Why did the outage happen?
The company tweeted on Thursday that it was experiencing a service disruption, though it ruled out a cyber attack on its platform.
Akamai had put out an alert about the Edge DNS service incident, noting a “partial outage” on its website, Reuters reported.
DNS (Domain Name System) is a service that translates readable domain names into machine readable IP addresses, connecting it to a server and delivering the requested page on the user's phone or laptop.
The company said that it had “implemented a fix” that resulted in the return of thousands of websites.
Later on Thursday, the company confirmed "a software configuration update triggered a bug in the DNS system, the system that directs browsers to websites".
"This caused a disruption impacting availability of some customer websites," it said in a post.
Rolling back the software update fixed the problem, Akamai said, apologising for the trouble.
Was this related to recent internet outages and could it happen again?
In June, another internet outage occurred under cloud CDN service Fastly.
Many news websites like CNN, Bloomberg, The Guardian and The Financial Times as well as other sites like eBay, Reddit and Twitch were shuttered under Fastly's partial outage, though services such as Shopify and Stripe were not affected.
The company identified the problem as a “service configuration".
Akamai was involved in another recent outage that hit bank and airline websites on both sides of the Pacific Ocean.
At that time, Akamai said that around 500 of its customers were briefly knocked offline because of a problem with one of its online security products.
The incidents have drawn attention to the stability of economically vital online platforms and the key role that a handful of little-known CDN companies play in keeping the web running.
It is probable that internet services and websites using cloud-based CDN service providers will see similar outages in the future — it's only a question of when.