Design of a CDN

CDN design

We’ll explain our CDN design in two phases. In the first phase, we’ll cover the components that comprise a CDN. By the end of this phase, we’ll understand why we need a specific component. In the second phase, we’ll explore the workflow by explaining how each component interacts with others to develop a fully functional CDN. Let’s dive in.

CDN components

The following components comprise a CDN:

• Clients: End users use various clients, like browsers, smartphones, and other devices, to request content from the CDN.
• Routing system: The routing system directs clients to the nearest CDN facility. To do that effectively, this component receives input from various systems to understand where content is placed, how many requests are made for particular content, the load a particular set of servers is handling, and the URI (Uniform Resource Identifier) namespace of various contents. In the next lesson, we’ll discuss different routing mechanisms to forward users to the nearest CDN facility.
• Scrubber servers: Scrubber servers are used to separate the good traffic from malicious traffic and protect against well-known attacks, like DDoS. Scrubber servers are generally used only when an attack is detected. In that case, the traffic is scrubbed or cleaned and then routed to the target destination.
• Proxy servers: The proxy or edge proxy servers serve the content from RAM to the users. Proxy servers store hot data in RAM, though they can store cold

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