How did it happen and what companies affected it?

Dozens of popular websites, apps and news outlets around the world were unavailable for nearly an hour early Tuesday after the outage of Fastly, the main Internet content delivery service. The attack, as in the May 7 ransomware attack on Colonial Pipeline, Fastly instead pointed to a technical issue and said a fix had been implemented, the Associated Press reported. During the outage, web users – including USA TODAY readers – received error messages like “Error 503 Service Unavailable” when trying to access the sites. The outage began shortly before 6AM EST and recovery began less than an hour later. In a message posted to Twitter at 7:09AM ET, Fastly said, “We have identified a service configuration that is causing disruptions across POPs globally and have disabled this configuration. Our global network is back online.” Still confused? Here’s what that means: What are CDNs? Websites, apps, and other companies use CDNs to move content around the world, reducing users’ access time. CDNs carry more than half of Internet traffic, says Akamai, a CDN and cloud services company, which describes CDNs themselves as online intermediaries. Simplified version of the process: A website wants to serve content such as a web page, video, or image and send it to a CDN, the CDN copies the content to Edge servers across the network, the process of copying is called caching. Cached information can be quickly retrieved and stored on a server for a specified period of time. Servers are grouped in strategically located locations all over the world. They are known as Points of Presence or POP. When a user searches for content – by typing a URL into a web browser for example – a CDN sends it from the nearest edge server. Imperva.com says the appropriate PoP is chosen based on regional traffic patterns, and CDNs say the benefits are: reduced actual travel distance to request content, less time between requesting a web page and loading the page to the device, and lower bandwidth costs. How do CDNs work? Let’s take a look at how this works, using the USA TODAY website or app you’re watching this story on in a simplified example: Some joke that the Internet is a chain of tubes, but that’s fairly accurate. There are wires in pipes everywhere that connect physical computers together, forming a network. You, the user or the customer, are making a request to download a file. This might look like the URL you type into a web browser. Or the link you clicked that brought you to this page, a website is mostly a set of files that your computer needs to download from a server, in our simple example, your request goes to a web server, which is a device somewhere. We used to rely on physical shelves in our server room downstairs. Now, most of our servers are virtual, but we’ll save an explanation of virtualization and cloud infrastructure for another day, this web server is our parent server, where the files originate from. You these files are yours. Your computer downloads them as data is sent over the Internet to your computer, but the files can be large, and your computer may be far from the server. And you may want to request a website or file over and over again, downloading it frequently is slow and expensive, and that’s where caching comes in. It is a concept in which the last seen version of a file or piece of data is saved for easy retrieval. Pictured as layers of onions, protecting central programs and computers from a lot of stress, one of the most important forms of caching is the content delivery network, and the content delivery network is what it sounds like: a collection of thousands of web servers containing the latest versions of websites and files and app data so users can download files and get things done faster. Companies like Akamai and Fastly maintain thousands of edge servers at points of presence all over the world. These are close to where you are, even in cell towers. Once someone visits a copy of a website, it saves a copy there for all subsequent users. So, unless you are the first person in your area to read this USA TODAY article, it will likely be served to you by the CDN’s Edge Server: Return to the original server. This causes major bottlenecks as servers are overloaded. Meanwhile, engineers are scrambling to respond to the flow of traffic and the stability of systems. Examples of sites affected by the outage are Twitch, Stack Overflow, Hulu, Quora, Vimeo, StripeCommerce, Amazon, PayPal, Shopify, EtsyInternet service, Google, GitHubGovernmentgov.ukSOURCE USA TODAY Reporting and Research Network; News agency; Reuters. Fastly.com; Akamai. Mitchell Thorson and Katie Vogel contributed to this report, and it’s possible that stories like this are possible because of our subscribers like you. Your support will allow us to continue to produce high quality press. Stay informed by subscribing to one of our newsletters.