CDN
Category: Marketing
What is CDN?
Content Delivery Network (CDN) is a geographically distributed network of servers that work together to provide fast delivery of internet content. CDN allows for the rapid transfer of resources needed to load internet content, including HTML pages, JavaScript files, style sheets, images, and video.
CDN is like a "copy" of your website located in many places around the world to be closer to your users.
How does CDN work?
- 1
User request
User from a specific region requests access to the website
- 2
DNS redirection
CDN redirects the request to the nearest CDN server (edge server)
- 3
Cached content
If the content is in the cache, it is delivered immediately from the edge server
- 4
Origin server request
If the content is not in the cache, the edge server downloads it from the origin server
- 5
Caching and delivery
The content is cached on the edge server and delivered to the user
Main components of CDN:
Edge servers (Edge Servers)
Located in different points of presence (PoPs) around the world, they are the closest to the end users and store the cached content.
Origin server (Origin Server)
The main server where the original content of the website is located. This is the source of truth for CDN.
Points of Presence (PoPs)
Physical places where the edge servers are located. The more PoPs, the better coverage.
Caching mechanisms
Special algorithms that determine how and how long to store the content in the cache.
Advantages of using CDN:
Improved performance
- Reduced loading time - the content is delivered from closer servers
- Better TTFB - faster first response from the server
- Optimized resources - automatic compression and minification
Improved security
- DDoS protection - distributed attack is handled by multiple servers
- Web Application Firewall (WAF) - filtering of malicious traffic
- SSL/TLS certificates - automatic management of certificates
Scalability and reliability
- Automatic scaling - handling traffic peaks
- Redundancy - if one server is damaged, others take the traffic
- Reduced load on the origin server
Economic benefits
- Reduced bandwidth costs - traffic is distributed
- Better SEO - the speed of the site is a factor for ranking
- Higher conversion - faster sites have better business results
When to use CDN?
Global audience
When your users are distributed in different geographical regions
High traffic
For sites with a large number of visits or seasonal traffic peaks
Media-heavy sites
Sites with many images, video or large files for download
E-commerce platforms
Where speed directly affects sales and conversion
Real-time applications
Applications requiring low latency and high performance
Types of content that CDN serves:
Static content
- HTML, CSS, JavaScript files
- Images (JPG, PNG, GIF, WebP)
- Fonts (WOFF, WOFF2)
- PDF documents
Media content
- Video streams
- Audio files
- Live streaming
- Podcasts
Dynamic content
- API responses
- Personalized content
- E-commerce products
- News and blogs
Software and applications
- Software downloads
- App store distributions
- Game patches
- OS images
Popular CDN providers:
Cloudflare
Advantages: Free plan, easy to use, good security
Suitable for: Small and medium businesses, startups
Amazon CloudFront
Advantages: Integration with AWS, high performance, advanced features
Suitable for: Enterprise customers, AWS users
Akamai
Advantages: Largest network, enterprise level, specialized solutions
Suitable for: Large corporations, media companies
Fastly
Advantages: Edge computing, real-time changes, high speed
Suitable for: Dynamic applications, real-time platforms
Google Cloud CDN
Advantages: Integration with Google Cloud, competitive prices
Suitable for: GCP users, technical companies
Steps for implementing CDN:
- 1
CDN provider selection
Based on budget, needs and geographical coverage
- 2
DNS configuration
Change the DNS records to point to CDN
- 3
Caching configuration
Define caching rules for different types of content
- 4
SSL/TLS configuration
Enable HTTPS and configure certificates
- 5
Testing and validation
Check performance and content correctness
- 6
Monitoring and optimization
Continuous monitoring and optimization
Good practices for using CDN:
- Cache strategically - different TTL for different content
- Use HTTP/2 or HTTP/3 for better performance
- Implement cache invalidation strategy
- Optimize images before uploading
- Use CDN for static and dynamic assets
- Configure CORS headers correctly for cross-origin requests