Style Jukebox is a cloud music streaming service that stores over 4.5 million songs for 125,000+ users. It faces challenges with scalability, availability, and latency due to its large user base and song library. It addresses these by using Azure services like SQL databases, storage, caching, and content delivery networks distributed across data centers for high performance as the system scales.

1. Ionut Antiu
www.get-jukebox.com
@johnnyantiu

2. 1. What are we talking about
2. What is Style Jukebox
3. What were the challenges
4. Wrap up

3. Style Jukebox is a High Fidelity cloud-music streaming service
that helps you keep all your music – be it bought, self-produced,
or imported from CDs or other media, always backed up and
synced across all your devices.

4. TRACTION
125,000+ registered users
52,000+ MAU
Peak of 13,000 users DAU
4,5+ million songs stored in the Cloud
50,000 – 100,000 songs listened daily

5. Low latency
Scalability
High Availability
OBJECTIVES

6. What is the basic Cloud architecture?

7. “LE SERVER”
Database SQL
Storage
API
LE CLIENT APP LE CLIENT APP LE CLIENT APP

8. “LE SERVER”
API
LE CLIENT APP LE CLIENT APP LE CLIENT APP
STORAGE
Windows Azure Storage Blobs
DATABASE
SQL Azure

9. Scale Up
Scale Out
Database, API, Content bandwidth, Website

10. Scale Up
One operation that cannot
be divided requires more compute power
(Audio/Video encoding, Your own DB, etc.)
Basic A1
1 Core AMD CPU
1,75 GB RAM
EUR 41/month*
G5, 32 cores
Intel Xeon
448 GB RAM
6 TB
EUR 4865/month*

11. Scale Out
Used for API, Website, etc.
Ex: Each machine can have a limited number of connected users
Basic A1
1 Core AMD CPU
1,75 GB RAM
EUR 41/month*
4x
Basic A1
1 Core AMD CPU
1,75 GB RAM
EUR 41/month*

12. SYNC SERVICE
API (GetSongURL, Login)
LE CLIENT APP LE CLIENT APP LE CLIENT APP
STORAGE
Windows Azure Storage Blobs
DATABASE
SQL Azure
BLOCK SERVICE
API (DownloadSong, UploadSong)

13. SYNC SERVICE
API (GetSongURL, Login)
LE CLIENT APP LE CLIENT APP LE CLIENT APP
STORAGE
Windows Azure Storage Blobs
DATABASE
SQL Azure
BLOCK SERVICE
API (DownloadSong, UploadSong)
MEMCACHE
Redis
Memcache Worker

14. The Memcache Worker
predicts and prepares the
results
Memcache Hit Ratio 86-91%
Reduced time of response with
80% to an average of 250ms

15. SYNC SERVICE
API (GetSongURL, Login)
LE CLIENT APP LE CLIENT APP LE CLIENT APP
STORAGE
Windows Azure Storage Blobs
DATABASE
SQL Azure
BLOCK SERVICE
API (DownloadSong, UploadSong)
MEMCACHE
Redis
Memcache Worker
CDN
Windows Azure CDN
CDN Worker

16. SYNC SERVICE
API (GetSongURL, Login)
LE CLIENT APP LE CLIENT APP LE CLIENT APP
STORAGE
Windows Azure Storage Blobs
DATABASE
SQL Azure
BLOCK SERVICE
API (DownloadSong, UploadSong)
MEMCACHE
Redis
Memcache Worker
CDN
Windows Azure CDN
CDN Worker
STORAGE
Upload Buffer
Upload Processing

17. SYNC SERVICE
API (GetSongURL, Login)
LOAD BALANCER
LE CLIENT APP LE CLIENT APP LE CLIENT APP
STORAGE
Windows Azure Storage Blobs
DATABASE
SQL Azure
BLOCK SERVICE
API (DownloadSong, UploadSong)
LOAD BALANCER
MEMCACHE
Redis
Memcache Worker
CDN
Windows Azure CDN
CDN Worker
STORAGE
Upload Buffer
Upload Processing
Download Processing

18. Load Balancer
Integrated in the Azure Cloud Services
Makes sure all instances have the same load
Auto-Scale creates new instances or removes automatically

20. SYNC SERVICE
API (GetSongURL, Login)
LOAD BALANCER
LE CLIENT APP LE CLIENT APP LE CLIENT APP
STORAGE
Windows Azure Storage Blobs
DATABASE
SQL Azure
BLOCK SERVICE
API (DownloadSong, UploadSong)
LOAD BALANCER
MEMCACHE
Redis
Memcache Worker
CDN
Windows Azure CDN
CDN Worker
STORAGE
Upload Buffer
Upload Processing
Download Processing
TRAFFIC MANAGER

21. SYNC SERVICE – WEST US
API (GetSongURL, Login)
DATABASE - AMSTERDAM
SQL Azure

22. SYNC SERVICE – WEST US
API (GetSongURL, Login)
DATABASE - AMSTERDAM
SQL Azure
~ 9,000 km * 3 calls = ~ 30,000 km
30,000 km : 300,000km/s = 100 ms

23. LE CLIENT APP LE CLIENT APP LE CLIENT APP
TRAFFIC MANAGER
SYNC – WEST US
API x VMs
LOAD BALANCER
BLOCK – WEST US
API x VMs
LOAD BALANCER
SYNC – WEST EU
API x VMs
LOAD BALANCER
BLOCK – WEST EU
API x VMs
LOAD BALANCER
CDN
Windows Azure CDN
STORAGE
Windows Azure Storage Blobs
MAIN DATABASE – WEST EU
SQL Azure
MEMCACHE – WEST EU
Redis
SLAVE DATABASE – WEST US
SQL Azure
MEMCACHE 2 – WEST US
Redis
STORAGE
Upload Buffer

24. Traffic Manager
stylejukebox.trafficmanager.net
4 VM machines
in West Europe
4 VM machines
in West US
Closest location to the user
Load balancing
Fail-over
Works for Websites, Cloud Services

25. Azure Datacenters

26. How to test?

30. Test 1
1,000 concurrent users
1 core machine

34. Test 2
1,000 concurrent users
4 core machine
$ 0,4 more per hour

37. Autoscale applies to Cloud Services and Websites
1 core machine can handle 200
connections simultaneous
4 core machine can handle 1,000
connections simultaneous

38. Monitoring

39. NewRelic

43. Always prepare for things to go wrong
Ex: Routers on the Internet

44. Low latency
Scalability
High Availability
OBJECTIVES

45. Ionut Antiu
www.get-jukebox.com
@johnnyantiu