This document provides an overview of the architecture of a social network system. It describes the core components including the user data storage, user activity system, notification and feed system (NFS), and big data system. It then focuses on describing the NFS in more detail, outlining its processes for storing activities and connections between users, aggregating this data to generate feed items and notifications, and displaying this information on various front-ends such as web, mobile, and APIs.

1. <SOCIAL NETWORK ARCHITECTURE>
@DEV ZONE

2. Overview architecture
Web Apps
Web Service APIs
Mobile Apps
4. Front-end
SSO
User
ranking
1. Core User
User Data Storage
Real-time
Notification
News Feed
2. User Activity System
User Activity Storage
3. Others
Real-time Chat
Search System Suggestion System
3. Big Data System
Big Data Storage
…
External Apps
Service Data
User
Administrator

3. Notification & Feed System –
NFS (Need For Speed :D)

4. 2. NFS: Definition
• Notification: to owner
• News feed: to owner connection

5. 2. NFS: Process
STORAGE
Activities
Connections
AGGREGATION
Feed Items
Notifications
DISPLAY
HTMLs
JSONs
AJAXs

6. 2. NFS: STORAGE
• Actions
• Ronaldo followed Messi
• Ronaldo tagged Messi on a Post
Subject Verb Object Target
User
Group
Follow
Add (friend, member)
Join
Post
Like
Share
Comment
Tag
Update
User
Group
Content
User
Group
Content

7. 2. NFS: STORAGE
• Connections
• Ronaldo follow Messi
• Ronaldo post a Content
• Ronaldo comment a Content
• Ronaldo join a Group
• …
Content
Group
User
User
post, follow,
tag, comment

8. 2. NFS: STORAGE
• Store actions -> activities
• [owner, [{ subject, verb, object, target }]]
• Examples:
• Ronaldo followed Messi
• [ Ronaldo, [{ Ronaldo, follow, Messi, null }]]
• Ronaldo added friend to Messi
• [ Ronaldo, [{ Ronaldo, friend, Messi, null }]]
• [Messi, [{ Ronaldo, friend, Messi, null }]]
• Ronaldo post Content on a Group
• [ Ronaldo, [{ Ronaldo, post, Content, Group }]]
• [Content, [{ Ronaldo, post, Content, Group }]]
• [ Group, [{ Ronaldo, post, Content, Group }]]
• Ronaldo tagged Messi on a Post
• [ Ronaldo, [{ Ronaldo, tag, Messi, Post }]]
• [ Messi, [{ Ronaldo, tag, Messi, Post }]]
• [ Post, [{ Ronaldo, tag, Messi, Post }]]

9. 2. NFS: STORAGE
• Store Connections
• Model
• [from, to, weight]
from to weight
A B 0.1
A C 0.2
C A 0.3

10. 2. NFS: AGGREGATION
• News feed Plans
• Pull: generate feed item for requested user as soon as he|she request
• Push: generate feed item for connected users as soon as a user action
• Pull & Push
• Active user  push
• Other  pull
• Schedule: generate feed item for connected user

11. 2. NFS: AGGREGATION
• Steps
1. Iterate Activities
2. Select Connections
3. Generate Feed items
 Focus Push plan

12. 2. NFS: AGGREGATION
• Select connections
• Activities: Ronaldo post Content on a Group
• Connections
owner subject verb object target
Ronaldo Ronaldo Post Content Group
Group Ronaldo Post Content Group
from to weight
Neymar Ronaldo 0.5
Kaka Ronaldo 0.5
Suarez Messi 0.8
Kaka Group 0.5
• Generate Feed items
• Feed items
owner order SVO VOT Data
Neymar 1.1 RPC PCG {}
Kaka 1.2 RPC PCG {}
Kaka 1.5 RPC PCG {}

13. 2. NFS: AGGREGATION
• Feed items
1.1
Feed item
0x0001
0x0002
1.2
Feed item
0x0001(RPC)
0x101(PCG)
1.5
Feed item
0x0001(RPC)
0x101(PCG)

14. 2. NFS: DISPLAY
• Front-ends
• Web: HTML, JSON, AJAX
• Mobile: HTML, JSON, XML
• API: JSON

15. 2. NFS: DISPLAY
• Group
• Example: Ronaldo and Messi commented on Content
• Get relation contents
• Generate HTML, JSON
1.2
Feed item
0x0011
0x101
1.5
Feed item
0x0001
0x101