CDN concept and usage in HLD - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does CDN stand for and what is its primary purpose?

CDN stands for Content Delivery Network. Its primary purpose is to deliver web content quickly and reliably to users by using a network of servers distributed across different locations.

beginner

How does a CDN improve website performance?

A CDN improves website performance by caching content closer to users, reducing the distance data travels, lowering latency, and decreasing load on the origin server.

intermediate

What is cache invalidation in the context of CDN?

Cache invalidation is the process of updating or removing cached content on CDN servers to ensure users get the latest version of the content.

beginner

Name two common types of content typically served by a CDN.

Two common types of content served by a CDN are static assets like images, CSS, JavaScript files, and streaming media such as videos.

intermediate

Why is geographic distribution important in a CDN?

Geographic distribution is important because it places servers closer to users worldwide, reducing latency and improving load times regardless of user location.

What is the main benefit of using a CDN?

A Improved server CPU speed

B Increased database storage

C Faster content delivery to users

D Better software development

CDNs speed up content delivery by caching data closer to users.

Which content is least likely to be cached by a CDN?

A JavaScript files

B Static images

C CSS files

D HTML pages that change frequently

Frequently changing HTML pages are less suitable for caching to avoid serving outdated content.

How does a CDN reduce load on the origin server?

A By caching content and serving it from edge servers

B By compressing data on the origin server

C By increasing the origin server's bandwidth

D By encrypting all data

CDNs cache content on edge servers, so fewer requests reach the origin server.

What does cache invalidation ensure in a CDN?

A That cached content is always encrypted

B That users receive the most recent content

C That servers never go offline

D That content is compressed

Cache invalidation updates or removes old cached content to serve fresh data.

Which factor is most important for CDN server placement?

A Proximity to users

B Server brand

C Operating system

D Number of CPU cores

Servers are placed close to users to reduce latency and improve speed.

Explain how a CDN works to improve user experience when accessing a website.

Think about how content travels from servers to users.

Describe the importance of cache invalidation in CDN usage and what could happen if it is not done properly.

Consider what happens if users see old versions of content.