LONDON – Dozens of websites around the world went offline briefly on Tuesday, including CNN, The New York Times and the UK government website, following a failure of the Fastly cloud service, demonstrating the importance of a small number of businesses behind the scenes is to operate the internet.

The unreachable sites also included some Amazon sites, the Financial Times, Reddit, Twitch, and The Guardian.

Fastly from San Francisco confirmed a problem just before 6 a.m. East Coast time. About an hour later, the company said, “The problem has been identified and a solution has been applied.”

Most of the websites appeared to be back online soon.

Fastly said it identified a service configuration that was causing interruptions, which means the outage appears to have been caused internally. Brief outages in Internet services are not uncommon and are rarely the result of hacking or other nonsense.

Still, the major futures markets in the US posted a sharp decline just minutes after the outage that forced the closure of the US’s largest fuel pipeline a month after a cyberattack

Fastly is a content delivery network, or CDN. It provides important, but behind the scenes, cloud computing “edge servers” for many of the popular websites. These servers store or “cache” content such as pictures and videos in locations around the world so that they are closer to users so that they can access them faster and more smoothly.

Fastly says its services mean that a European user visiting an American website can get the content 200 to 500 milliseconds faster.

Kentik’s measurement of Internet traffic showed that Fastly recovered from the outage about an hour after the outage in the morning European time, before most Americans were awake.

“Looks like it’s coming back slowly,” said Doug Madory, an Internet infrastructure expert at Kentik. He said, “It’s serious because Fastly is one of the largest CDNs in the world and this was a global outage.”

The impact of Fastly’s problems shows the relative fragility of Internet architecture given its heavy reliance on big tech companies – like Amazon’s AWS cloud services – as opposed to a more decentralized group of companies.

“Even the largest and most demanding companies have failures. But they can also recover pretty quickly, ”said Madory.

When the outage occurred, some visitors who tried to access received a message saying “Fastly error: unknown domain:”. Attempts to access the Financial Times website yielded a similar message, while visits to the New York Times and the UK government’s website returned an “Error 503 Service Unavailable” message along with the line “Varnish Cache Server” Technology, on which Fastly builds.

Down Detector, which is tracking internet outages, has published reports of dozens of websites that have gone down.

Frank Bajak in Boston and Zen Soo in Hong Kong contributed to this report.