> Social Graph — TAO

How Facebook models billions of relationships with objects, associations, and a two-tier cache

+ Create Object

▸ 💡 Objects and Associations: The Social Graph Data Model

↔ Create Association

↔ Bidirectional FRIEND ⟷ FRIEND
▸ 💡 Why Not SQL? The Memcache-MySQL Problem

🕸️ Social Graph

No objects yet. Create some above to see the graph.

▸ 💡 TAO API: Point, Range, and Count Queries

🔍 TAO Query Panel

assoc_get(id1, type, id2) — Does this association exist?

⚡ Two-Tier Cache Simulator

Client
→
Follower 0/8
→
Leader 0/20
→
MySQL

Follower

0 Hits
0 Misses
0.0% Hit Ratio

Leader

0 Hits
0 Misses
0.0% Hit Ratio

MySQL (Storage)

0 Reads
0 Total
▸ 💡 Two-Tier Caching: Leaders and Followers
▸ 💡 Sharding and Data Distribution
▸ 💡 Consistency Model: Eventual vs Strong
▸ 💡 System Design Overview
▸ 💡 References & Further Reading