CDN

Content Delivery Network (CDN)

What is a CDN?

A Content Delivery Network (CDN) is a distributed network of servers that deliver web content and resources to users based on their geographic location. CDNs aim to improve the performance, reliability, and security of web applications by caching content closer to the end-users.

When to use?

Use a CDN to improve performance, scalability, security, and reliability of your web applications.

How does it work?

When a client, such as a browser or mobile app, sends a request for content, the request is routed to the nearest CDN server. The CDN server then serves the cached content directly to the client, reducing the load on the origin server and decreasing latency.

Key features

  • Performance: Reduces latency by serving content from servers closer to the end-users, resulting in faster load times.
  • Scalability: Handles large volumes of traffic by distributing requests across multiple servers, preventing any single server from being overwhelmed.
  • Security: Provides protection against DDoS attacks, data breaches, and other security threats by acting as a barrier between the client and the origin server.
  • Reliability: Ensures high availability and uptime by distributing content across multiple servers, reducing the risk of server failures.

Common Use Cases

Speeds up the delivery of web content by caching static content and optimizing resource delivery. Improves performance, reduces latency, and enhances user experience.

Example of static content includes: images, videos, CSS, JavaScript files, and other assets that do not change frequently.

How to set up a CDN?

To set up a CDN for your web application, follow these steps:

  1. Choose Provider: Select a CDN provider that meets your requirements.
  2. Integrate: Configure your web application to use the CDN by updating the URLs of static assets to point to the CDN's domain.
<!-- Original URLs -->
<link rel="stylesheet" href="/css/styles.css">
<script src="/js/scripts.js"></script>
<img src="/images/logo.png" alt="Logo">
 
<!-- CDN URLs -->
<link rel="stylesheet" href="https://cdn.example.com/styles.css">
<script src="https://cdn.example.com/js/scripts.js"></script>
<img src="https://cdn.example.com/images/logo.png" alt="Logo">

In this example, the URLs for the CSS, JavaScript, and image files have been updated to point to the CDN.

Disadvantages

  • Cost: CDNs can be expensive, especially for high-traffic websites or applications.
  • Dependency: Relying on a third-party CDN provider means that your website's performance and availability are dependent on the provider's infrastructure. Any downtime or performance issues on the provider's end can impact your website.
  • Cache Invalidation: Ensuring that cached content is up-to-date and avoiding stale content can be challenging.

Popular CDN Providers

IntroductionWebhooks