...
...
...
...
...
...
...
...
...
...
...
On this page.
| Table of Contents |
|---|
Introduction
News feed is the constantly updating list of stories in the middle of the home page. It includes status updates, photos, links, video, etc.
Part 1 - Understand the problem and establish design scope
Accessible via Mobile App or/and Web App ? | Both |
|---|---|
Features ? | Publish and See other posts (from other users) |
How is sorted the news feed ? | Reverse chronological order |
How many friends user can have ? | 5000 |
Traffic volume ? | 10 million per day, active users |
Contain images, videos or just text ? | All. |
Part 2 - High-Level design
...
2 flows :
Feed publishing → user publishes a post, corresponding data is written into cache and DB.
Newsfeed building → news feed is built by aggregating friends’ posts in reverse chronological order.
Part 3 - Deep dive design
Flow Feed Publishing
Focus is on Web servers and the fanout service.
...
Flow Newsfeed Retrieval
Focus is on the CDN and the News Feed Service :
Service fetches complete user and post objects from caches.
News feed is returned in JSON format back to the client for rendering.
...
Part 4 - Pros & Cons
Need to validate how to scale the DB (Master-Slave replication, Read Replicas, DB Sharding, etc.)
How to keep Web Tier Stateless
etc…