Content delivery with CDN in HLD - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a CDN in simple terms?

A CDN (Content Delivery Network) is a group of servers placed in different locations that store copies of content to deliver it faster to users nearby.

beginner

Why do websites use CDNs?

Websites use CDNs to make their content load faster, reduce the load on their main servers, and improve user experience by serving content from nearby servers.

intermediate

What is cache miss and cache hit in CDN context?

Cache hit means the CDN server has the requested content and delivers it quickly. Cache miss means the content is not on the CDN server, so it fetches it from the origin server first.

intermediate

How does a CDN improve scalability?

A CDN spreads user requests across many servers worldwide, so the origin server handles fewer requests, allowing the system to serve more users without slowing down.

beginner

Name two common types of content typically delivered by CDNs.

Static files like images, videos, stylesheets, and scripts are commonly delivered by CDNs because they don’t change often and benefit from caching.

What is the main purpose of a CDN?

A To replace the main database

B To deliver content faster by using servers close to users

C To store user passwords securely

D To generate website content dynamically

CDNs deliver content faster by caching it on servers near users.

What happens during a cache miss in a CDN?

A Content is fetched from the origin server and then cached

B Content is served immediately from the CDN

C User request is denied

D CDN deletes the content

On a cache miss, the CDN fetches content from the origin server and caches it for future requests.

Which content type is best suited for CDN delivery?

A Real-time chat messages

B Dynamic user data

C Static images and videos

D Database transactions

Static content like images and videos are ideal for CDN caching and delivery.

How does a CDN help reduce load on the origin server?

A By caching and serving content directly to users

B By increasing server CPU speed

C By deleting unused files

D By blocking user requests

CDNs cache content and serve it directly, reducing requests to the origin server.

Which of these is NOT a benefit of using a CDN?

A Reduced server bandwidth usage

B Better scalability

C Improved content delivery speed

D Automatic content creation

CDNs do not create content; they only deliver cached content faster.

Explain how a CDN works to improve website performance.

Think of how a package delivery service uses local warehouses to deliver faster.

Describe the difference between cache hit and cache miss in a CDN.

Compare it to finding a book in your local library versus ordering it from a distant store.