CDNs are networks that connect website content, such as videos, text, and photos, to other servers spread across different regions of the world.
On Tuesday, 8, access to some of the world’s top sites was interrupted due to a server issue that affected Fastly, a network content delivery company. error hit domain eg new York Times, heroine, Spotify, reddit, among others, and affected cities on all continents—perhaps you have noticed. But how does Fastly work and why did the server stop working? The answer goes through something called a Content Delivery Network (CDN).
CDNs are networks that link website content, such as video, text, and photos, to other servers spread across different regions of the world so that they can be distributed locally. They are necessary because many of the sites and services affected in Tuesday’s crash usually do not have servers in more than one location.
What a CDN does is take a “copy” of the content from that server and send it to various networks around the world, which can continue to make “copies” until they reach multiple access points within the same country or city. Arrive.
“If you’re going to access a US website and you’re in Brazil, your Internet network doesn’t go to the United States to receive the content: a company has already taken this content and put it on a server.” left, for example, in So Paulo, closer to the Brazilian user”, explains Daniel Batista, a professor at the Institute of Mathematics and Statistics at USP.
It’s like a waterfall: Your streaming service sends a movie to a CDN, the CDN sends the same movie to a server in So Paulo and you watch it from the server next to you. It generates speed, transmission quality to load movies and avoids the overload of that first server, which certainly can’t handle the whole world watching the same movie.
Why do companies use CDN networks?
Hiring a company to act as a CDN, such as Fastly, is common among large content producers to facilitate and guarantee access in multiple countries – and with it, the potential commercialization of these services. Since CDN guarantees the quality of transmission, image and page loading, it is an option to enable users to access the platform wherever they are.
This feature also works because CDN companies have their own outsourced services in each country. In this case, the network can go through even more servers, depending on how the distribution is done across regions.
However, they are not free from defects, as could be seen on Tuesday. Like any Internet server, these systems are prone to failure, according to Rodrigo Izidoro, professor of computer science at the Centro Universitário FEI.
“A network of this type, like other services that we currently have online, can go down for many reasons. Infrastructure problems, server problems or even attacks. As well as the workload on the servers. In this context, the server may receive many requests, far more than it can handle”.
Provides fast explanation
In Fastly’s case, there was a software failure that started when one of its customers changed their settings. The blackout raised questions about how much the Internet relies on certain infrastructure companies.
“This outage was widespread and severe, and we truly regret the impact it will have on our customers and everyone who depends on them,” the company said in a blog by its senior engineering and infrastructure executive Nick Rockwell on Wednesday.
Fastly also promised to explain why it failed to detect software bugs during its testing process. The company said the problem was in a software update sent to customers on May 12, but was not triggered until an unidentified customer made a configuration change that triggered the problem. According to the company, it “made errors in 85% of our networks”./ with Reuters