Error 503 Service Unavailable: Why did major sites like Amazon, Reddit go down?

No, you weren’t the only one!

There was a major global outage on the morning of June 8, rendering many of the world’s popular websites inaccessible for more than an hour. On Tuesday morning, most popular websites came to an abrupt halt, with users presented with an ominous warning message “Error 503: Service Unavailable”. 
​
Before delving deeper into the issue, let us understand what this error means.

What is Error 503?

​The message ‘503 Service Unavailable’ is an error response code that indicates the server is not ready to handle the request. Common causes are a server that is down for maintenance, or that is overloaded.

​The global outage on June 8th, 2021 happened because of an issue with the content delivery network (CDN) of American cloud computing services provider “Fastly.” To better understand the issue, let’s look at the technicalities of CDN.

​
What is a CDN?

A CDN represents a geographically distributed network of servers that collaborate to provide Internet content quickly. They keep the content near to the networks of telecom service providers. Most of the web traffic is now routed through CDNs around the world.

Platforms with enormous amounts of data stored in global libraries, such as Netflix, Facebook, and Amazon, host their geographically relevant material closer to where it will be consumed. This ensures the end customer can access the content faster.
​
CDNs have gained tremendous popularity over the recent years. One such company is “Fastly,” the company in question for the outage on June 8.

​
What should we know about Fastly?

Fastly is a cloud computing service company based in the United States. Fastly advertises its network as an edge cloud platform that allows developers to extend their core cloud infrastructure, bringing it closer to users.

The Fastly edge cloud platform includes their content delivery network, image optimization, cloud security, and load balancing services. Apart from Fastly, the other leading CDN providers include Akamai Technologies, Cloudera, and AWS.

While CDN failures are rare, but once they occur, there is a massive global outage like the one on June 8. Now that we have understood CDNs let’s look at the actual reason behind the outage.

​
Why was there a major Internet Outage on June 8th?

https://www.theguardian.com/technology/2021/jun/08/edge-cloud-error-tuesday-internet-outage-fastly-speed

Many websites and apps throughout the world were down for nearly an hour after Fastly, a major content delivery network, announced a widespread failure on Tuesday. The problem was caused by an outage at Fastly, a cloud service provider.

On its service status website, the company said it had identified the problem and fixed the issue. Service for sites and apps started to be restored around 7 a.m. ET, although Fastly said some customers experienced longer load times as a residual effect of the problem.

Dozens of nations across the Americas, Europe, Asia, and South Africa were affected by the outage. Fastly said it had discovered a service setting that was causing server outages. The company has disabled that setting. Some of the websites that were affected are listed below.


Which websites were affected?

Amazon.com, Reddit, Twitch, Spotify, Pinterest, Stack Overflow, GitHub, gov.uk, Hulu, HBO Max, Quora, PayPal, Vimeo, and Shopify are some of the big names. Prominent news websites impacted were the Financial Times, the Guardian, the New York Times, CNN, and Verge.
​
Though short-lived, the outage took a significant toll on several companies.


Global Impact of the Outage

Some of the noticeable impacts of the global outage are as follows:

1. The gov.uk website was down during the outage, tweeted the UK’s attorney general.
2. According to the Financial Times, the disruption caused issues for citizens booking COVID-19 vaccinations or reporting test results.
3. News organizations’ websites, such as the Financial Times, the Guardian, and Bloomberg News, were also affected.
4. According to back-of-the-envelope estimates from media measurement firm Kantar, websites lost nearly $29 million in digital ad income each hour during the downtime.
5. As per Downdetector.com, nearly 21,000 Reddit users reported troubles with the social media network during the outage, while more than 2000 Amazon users reported troubles.
6. Shares of New York-listed Fastly were up 7.7% after being down nearly 4% in pre-market trading.

Even in the past, there have been several issues with CDNs causing massive global outages. Let us look at one such failure.


CDN issues in the Past

This isn’t the first time that a CDN failure has caused numerous other websites to fall as a result. Cloudflare, another large worldwide cloud platform, had previously had issues that damaged its client websites in 2020. Sites like Discord, Feedly, Politico, Shopify, and League of Legends were affected by the Cloudflare outage.


What did we Learn?

CDNs are a vital component in making the internet work the way it does, and when a company’s CDN goes down for whatever reason, that can result in a lot of trouble. While the outage has been addressed and things are back to normal, incidents like these serve as reminders of the need for back-end companies like Fastly.

They may not get as much attention as Facebook or Apple, but the internet would not exist as it does today without them.
​