The document discusses how the mobile game company wooga used Redis as the data store for their Facebook game Happy Hospital to achieve their goals of 1 million daily active users with a small production cluster. It describes their data model of storing user and game entity data in Redis hashes and lists, and how their architecture evolved over time from the initial setup in 2010 to the current production setup in 2011 to address Redis limitations around memory usage and durability. The document highlights Redis' performance and stability but also warns of memory consumption and durability issues.

1. Redis to the Rescue?
Berlin Buzzwords
2011-06-07

2. Who
• Tim Lossen / @tlossen
• backend developer at wooga
• Berlin, Germany

4. apps.facebook.com/happy-hospital

5. Goals
• 1 million players per day
(“DAU = daily active users”)

6. Goals
• 1 million players per day
(“DAU = daily active users”)
• small production cluster
- less operational overhead
- cheaper

7. Architecture

9. Data Model
• user = single Redis hash
- each entity stored in hash field
(serialized to JSON)
• custom Ruby mapping layer
(“Remodel”)

10. {“level”: 4,
1220032045 u1
“xp”: 241}
u1_pets [“p7”, “p8”]
{“pet_type”:
p7
“Cat”}
{“pet_type”:
p8
“Dog”}
{“level”: 1,
1234599660 u1
“xp”: 22}
u1_pets [“p3”]
... ...

11. {“level”: 4,
1220032045 u1
“xp”: 241}
u1_pets [“p7”, “p8”]
{“pet_type”:
p7
“Cat”}
{“pet_type”:
p8
“Dog”}
{“level”: 1,
1234599660 u1
“xp”: 22}
u1_pets [“p3”]
... ...

12. Setup A (July 2010)

13. Setup B (Nov 2010)

14. Setup B (Dec 2010)

15. Analysis
• Redis virtual memory not
compatible with:
- persistence
- replication

16. Setup B’ (Dec 2010)

17. Setup C (Dec 2010)

18. Setup D (May 2011)

19. Status
• peak traffic:
- 3000 requests/s
- 35000 Redis operations/s
• average backend response time:
- 10 ms

20. appdata.com

21. Goals
• 1 million DAU
• small production cluster

22. Production Cluster
Text
(1x intel core i7 X980,
6 cores, 24 gig ram)

23. Goals
• 1 million DAU
• small production cluster

24. Redis Highlights
• high sustained throughput /
performance
• very stable
• active & helpful community

25. Redis Gotchas
• memory consumption
- fragmentation!
• durability

26. Q&A

27. redis.io
github.com/tlossen/remodel
wooga.com/jobs