What Are Content Delivery Networks & Why Big Websites Hang Together
You don’t hear much on content delivery networks, or CDNs, until they stop broadcasting. A global outage of major websites on June 8 that lasted about an hour was caused by problems at San Francisco-based Fastly Inc. He took down websites like the New York Times, Bloomberg News, and even the UK government.
What is a content delivery network?
It is a kind of bridge between a website or application and a user, helping to quickly distribute data across the internet on behalf of some of the most popular online companies. CDN providers do this by hosting multiple servers and directing people who call up a webpage to the geographically closest webpage, rather than sending them back to the origin. Suppose a company’s website is based in the United States and generates traffic from France, it is possible that a CDN provider has a server in France that will direct users there.
Who uses them?
These networks are popular with large, high traffic websites and those with large downloads. The list of people affected by the June 8 outage included Amazon, Spotify, Twitch, Shopify and Etsy, according to Downdetector, a website that tracks internet service outages. Other major CDN providers include Cloudfare, Akamai, and MaxCDN.
Why use them?
Along with the speed and ease of serving more customers simultaneously, CDNs are in a better position to deliver content such as high-resolution video without interruption. They can also divert traffic to different servers if demand is high or there is a sudden spike, allowing websites to keep running when under pressure. On the other hand, they are expensive, do not have servers everywhere and, as this latest episode shows, make companies put the fate of their websites in the hands of a third party.
What happened with Fastly?
CDNs very rarely fail, but when they fail it can be spectacular. There are many similarities between this outage and an issue with rival Cloudflare last year. Cloudflare’s problems arose because, put simply, the company’s engineers tried to reroute internet traffic and everything blew up. Since website traffic is routed through the servers of a CDN, when the servers go down, so do everything else. These issues are also difficult to avoid and often arise when businesses need to update their systems. Quickly attributed the incident to “a service setup that triggered disruption to our POPs (points of presence) globally.”
Was it a hack?
There is no evidence to suggest that Fastly’s issues were the result of a malicious cyber attack. In contrast, all website system administrators know that network outages and downtime can occur regardless of the size of their hosting platform.