Media storage and CDN in HLD - Cheat Sheet & Quick Revision

Recall & Review

beginner

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

A CDN is designed to deliver media and other content to users quickly by caching copies of the content on servers located close to the users, reducing latency and load on the origin server.

beginner

Why is media storage often separated from application servers in system design?

Separating media storage from application servers helps scale storage independently, improves performance by offloading heavy media data, and allows specialized storage solutions optimized for large files.

intermediate

What is 'cache invalidation' in the context of CDNs?

Cache invalidation is the process of removing or updating cached content on CDN servers when the original media changes, ensuring users receive the latest version.

intermediate

Name two common storage types used for media storage in large-scale systems.

Object storage (like Amazon S3) and block storage are commonly used. Object storage is preferred for its scalability and metadata support, ideal for media files.

intermediate

How does a CDN improve scalability for media-heavy applications?

By distributing media content across many edge servers worldwide, a CDN reduces the load on the origin server and handles many user requests simultaneously, allowing the system to scale efficiently.

What does a CDN primarily reduce for end users?

A Database queries

B Storage cost

C CPU usage

D Latency

A CDN reduces latency by serving content from servers closer to the user.

Which storage type is best suited for storing large media files?

A In-memory cache

B Object storage

C Relational database

D Block storage only

Object storage is optimized for large files and scalability, making it ideal for media.

What happens during cache invalidation in a CDN?

A Cached content is updated or removed

B New content is uploaded to origin server

C User requests are blocked

D Media files are compressed

Cache invalidation updates or removes outdated cached content to keep it fresh.

Why separate media storage from application servers?

A To scale storage independently

B To reduce network bandwidth

C To increase CPU power

D To simplify database queries

Separating storage allows independent scaling and better performance.

Which is NOT a benefit of using a CDN?

A Improved content delivery speed

B Reduced load on origin servers

C Automatic media file editing

D Better handling of traffic spikes

CDNs do not edit media files automatically; they focus on delivery.

Explain how a CDN works to improve media delivery performance.

Think about how content gets closer to the user.

Describe the key considerations when designing media storage for a large-scale system.

Focus on storage type, separation, and integration with CDN.