S18. What are CDNs, why are they needed, and what are common examples? Flashcards
What are CDNs?
CDNs, or content delivery networks, are distributed networks of servers strategically positioned across geographic locations to be able to serve content end-users more efficiently.
How do CDNs work?
CDNs work by caching and distributing content closer to users, reducing latency, improving website performance, and offloading traffic from origin servers. When a user requests content, the CDN delivers it from the nearest cache server rather than the origin server.
Why are CDNs needed?
CDNs are needed to address the challenges posed by the increasing demand for web content from an ever-growing global population of Internet users. As Internet traffic grows, websites face performance issues such as slow loading times and high latency, particularly for users located far from the origin server.
How do CDNs solve the issue of high latency for uses located far from the origin server?
CDNs solve these issues by caching copies of web content on servers located closer to end-users, reducing the distance data must travel.
How does CDN balance server load?
For example, if a popular video, that may be requested by millions of users in a day, is cached in multiple locations worldwide, users can access it from the nearest CDN server instead of overwhelming the origin server. CDNs also have load balancing algorithms to distribute traffic across multiple servers, preventing any single server from becoming a bottleneck
How do CDNs prevent bandwidth bottlenecks?
The distribution of traffic by CDNs reduces the strain on network infrastructure and helps manage bandwidth more efficiently. For websites and services with heavy multimedia content, such as streaming platforms, CDNs are essential in preventing bandwidth bottlenecks and ensuring smooth playback.
How do CDNs ensure content availability?
If one CDN server fails, requests are automatically redirected to another server with a cached copy of the content. This helps maintain high availability and reliability, ensuring that users can access content without interruption.
How do CDNs provide security?
CDNs provide an additional layer of security against Distributed Denial of Service (DDoS) attacks. During a DDoS attack, malicious actors flood a website with excessive traffic, attempting to overwhelm the server. CDNs can detect and filter out malicious traffic before it reaches the origin server.
What are examples of CDNs?
One of the most widely used CDNs is Akamai, with servers located in over 135 countries, providing content from various industries, such as media, e-commerce, and finance. Other examples of CDNs include Cloudflare and Amazon CloudFront.
