On November 18, a strange picture appeared on the Internet worldwide. The text “500 Internal Server Error” is written in large letters on that picture. If you pay attention, you will see that it says “Visit Cloudflare for more information”. Also as shown in the image below, “Browser” and “Host” are green or active but Cloudflare has a red light.
That’s the fact—Cloudflare was down yesterday. Joking about this, memes spread on social media. An engineer working at Cloudflare is looking at the report, a billion-dollar loss of billion dollars every minute is happening worldwide.
At times like this, when systems like Cloudflare go down, many people around the world feel that the Internet is standing on an invisible thread. The work is done when the thread is torn somewhere. Many are surprised – is it possible? Is this huge network standing on just a few threads? Answer – Yes. But if you answer in one word like this, nothing is understood about the matter. In this article, we will discuss the ‘invisible threads’ within the structure of the Internet. Let’s take a look at why a framework like Cloudflare brings the entire internet world to a standstill.
Basic structure of the Internet
We often say “Cloud” when talking about the Internet. Indeed, the Internet does not pass through the clouds or the sky. Rather, our internet is built by thousands of miles of huge cables (actually Fiber Optic Cables) and huge AC rooms that go under the ground and under the sea. Inside this AC room is the server—think of it as a larger version of your home’s CPU.
The fact is, when you type a URL (URL) in the browser—such as bigganchinta.com.com—and press Enter, one thing after another happens in the blink of an eye. The major players in this grand journey are:
- Client: Your Mobile or Computer
- ISP: Your local Internet provider
- Backbone: The main optical fiber highway
- Router/Gateway: Gateway to the network
- CDN/Reverse Proxy (eg Cloudflare)
- Main Server (eg AWS)
How Cloudflare Works
Imagine, you wrote a letter, dropped it in the postbox—but the letter didn’t arrive, because the Post Office disappeared! Here the Post Office is the CDN. Just as there is no internet when your ISP is down, a gateway or CDN is a bigger problem.
- Why is CDN important?
- To reduce latency
- To cache popular information
- And the biggest reason—Security
- Hackers can crash the server by sending billions of requests.
Cloudflare therefore:
- Checks whether the request is Human or a Bot
- Hides Server IP
- User keeps IP to himself
- As a result, it cannot be easily bypassed.
What happened on 18 November
Cloudflare was down. Even if your favorite websites like Facebook or bigganchinta are fine, you are unreachable. The middle CDN was down.
The browser then showed:
- 502 Bad Gateway — Gateway failed
- 500 — Server-side problem
- 404 — Information not found
About 20% of the world’s websites use Cloudflare. So when it is down, it seems that there is no internet in many places.
Source: Cloudflare.com, Wikipedia
