Architecture & Components Flashcards

What is the primary function of a Content Delivery Network (CDN)?

Answer: Deliver web content globally

The primary function of a Content Delivery Network (CDN) is to deliver web content, such as images, videos, and web pages, to users across the globe quickly and efficiently. It achieves this by distributing content to servers located closer to end-users. This geographical distribution minimizes latency and improves the loading speed of websites and applications, enhancing the user experience.

What are edge servers in a CDN?

Answer: Servers near users

Edge servers in a CDN are strategically located servers positioned at the 'edge' of the network, meaning they are geographically closer to the end-users. These servers cache copies of content, allowing them to deliver data with minimal delay. By reducing the physical distance data needs to travel, edge servers significantly improve content loading times and overall website performance.

What is the role of origin servers in a CDN?

Answer: Store original content

Origin servers in a CDN architecture are the primary source where the original, authoritative versions of web content are stored. When a user requests content, and it's not available in a CDN's edge server cache, the edge server retrieves it from the origin server. This ensures that the CDN always serves the most up-to-date content while offloading direct traffic from the origin.

What is caching in a CDN?

Answer: Storing content near users

Caching in a CDN refers to the process of storing copies of frequently accessed web content on edge servers that are geographically closer to users. When a user requests content, the CDN checks if a cached version is available on a nearby edge server. This significantly reduces the time it takes for content to reach the user, improving website speed and reducing the load on origin servers.

What does latency refer to in CDN performance?

Answer: Delay in content delivery

In CDN performance, latency refers to the delay or time lag experienced between a user's request for content and the delivery of that content. High latency can result in slow loading times and a poor user experience. CDNs aim to minimize latency by serving content from edge servers located closer to the user, thereby reducing the physical distance data must travel.

What is load balancing in a CDN?

Answer: Distributing requests evenly

Load balancing in a CDN is the process of efficiently distributing incoming user requests across multiple available edge servers. This ensures that no single server becomes overloaded, which could lead to performance degradation or downtime. By evenly distributing the traffic, load balancing optimizes server utilization, maintains high availability, and ensures consistent content delivery speeds for all users.

What is the function of DNS in a CDN?

Answer: Direct requests to optimal server

DNS (Domain Name System) plays a crucial role in a CDN by directing user requests to the optimal edge server. When a user types a website address, the CDN's DNS service resolves the domain name to the IP address of the closest and most available edge server. This intelligent routing ensures that content is delivered from the server that can provide the fastest response, minimizing latency.

What is a common CDN security feature?

Answer: DDoS protection and SSL

CDNs incorporate robust security features to protect web content and ensure secure delivery. Two common and vital features are DDoS (Distributed Denial of Service) protection, which defends against malicious traffic overwhelming servers, and SSL (Secure Sockets Layer) encryption. SSL encrypts data in transit, safeguarding sensitive information and ensuring secure communication between users and the CDN.

Why is scalability important in CDN architecture?

Answer: Handle growing traffic efficiently

Scalability is paramount in CDN architecture because web traffic can fluctuate dramatically, especially during peak events or viral content. A scalable CDN can efficiently handle a growing number of user requests and increasing data volumes without compromising performance. This ensures that content remains accessible and fast-loading, regardless of the demand, providing a consistent user experience.