A year ago we started a big change in FTBpro. We completely changed the visual design, moved to a single page architecture and started exploring new ways to minimise load on our servers - both when serving our actual website, and mobile API responses.We'll focus on how scaling considerations are now an integral part of our architecture, which enabled us to serve 20x more traffic than we did 1 year ago, with the same setup and with no additional costs.

1. Growing X20 without
spending an extra
penny on hosting
Dor Kalev, CTO @ FTBpro

2. Largest fan-generated media platform in
global football
130m pageviews / month

3. a Football fan #musthave
1M+ mobile installs

4. Content is king

5. Single Page Application
Phantom.js renders pages on the server-side for SEO,
crawlers and mobile web performance
Load Balancer
Memcached
Redis
Web 1 Web 2 Web 3
MySQL MongoDB ElasticSearch
Amazon Web Services
NginX
+
Ruby on
Rails
PhantomJS
Web 4

6. How do we scale
post pages?

7. Each Render Server can return
1 client request at a time
1:1
Client
Server
Render

8. Linear correlation between
clients and servers
1:1
Client
Server
Render
Client
Server
Render

9. A cache server can handle
over x10 more traffic
10:1:1
Cache
Server
Render
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client

10. Cache server still consumes CPU and
with more traffic, more servers are needed
20:2:1
Cache
Server
Render
Cache
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client

11. Accelerator like NGINX+MemCached or
Varnish can be x100 more efficient than
plain App Server Cache
100:1:1
Server
Render
Accelerator
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
https://www.igvita.com/2008/02/11/nginx-and-memcached-a-400-boost/
https://www.varnish-cache.org

12. 200:2:1
Server
Render
Accelerator
Accelerator
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Accelerator also runs on limited hardware
and needs more CPU in order to scale

13. Enter CDN
∞:1
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
CDN
Server
Render

14. Client
Client
My
Tiny
Server
PoP
CDN
SERVER
CDN
SERVER
CDN
SERVER
PoP
CDN
SERVER
CDN
SERVER
CDN
SERVER
PoP
CDN
SERVER
CDN
SERVER
CDN
SERVER
Client
Client
Client Client Client Client
Client
What’s a CDN?

15. What’s a CDN?
• Content Delivery Network
• A set of autonomic distributed cache servers
• Serve cache from a location geographically
close to the client
• e.g: Akamai, Cloudflare, Fastly, Highwinds,
Edgecast, Cloudfront

16. Enter Trouble
∞:1
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
Client
CDN
Server
Render

17. Fixing minor Typo?
Need to Refresh Cache??

18. TTL vs. ON CHANGE
Cache Policy

19. Purge by URL can take over an
hour on classic CDNs
Z
Z
Z

20. Purge by TTL - isn’t realtime &
causes redundant server hits
CPULOAD
0
7.5
15
22.5
30
TIME
1 2 3 4 5 (TTL) 6 7 8 9 (TTL) 10 11 12

21. multiply by all articles
CPULOAD
0
7.5
15
22.5
30
TIME
1 2 3 4 5 (TTL) 6 7 8 9 (TTL) 10 11 12

22. TTL = Constant waste of CPU
CPULOAD
0
7.5
15
22.5
30
TIME
1 2 3 4 5 6 7 8 9 10 11 12

23. Better Solution?

24. abuse new CDN
technologies
Super Fast Purge + Smart API!
!
!
!
!
!
e.g. Fastly, EdgeCast

25. cache forever +
purge on demand
0
7.5
15
22.5
30
1 (release) 2 3 4 5 6 7 8 9 (purge) 10 11 12

26. fast purge at ~10-45 seconds

27. Advantages
• ∞ scaling
• cheap
• fast
• keep the stack simple

28. Caveats
• Purging everything can lead to downtime, e.g.
when deploying
• User Specific content can’t be cached with the
entire page
• Downtime on massive Push Notifications

29. Massive Push Notification + cold CDN
Cache = traffic goes to app servers
CPULOAD
0
250
500
750
1000
TIME
1 (PN) 2 3 4 5 6 7 8 9 10 11 12

30. Client
Client
My
Tiny
Server
PoP
CDN
SERVER
CDN
SERVER
CDN
SERVER
PoP
CDN
SERVER
CDN
SERVER
CDN
SERVER
PoP
CDN
SERVER
CDN
SERVER
CDN
SERVER
Client
Client
Client Client Client Client
Client
Render (or cache & serve) X number of calls
in parallel = self-DDoS

31. Client
Client
CACHE
PoP
CDN
SERVER
CDN
SERVER
CDN
SERVER
PoP
CDN
SERVER
CDN
SERVER
CDN
SERVER
PoP
CDN
SERVER
CDN
SERVER
CDN
SERVER
Client
Client
Client Client Client Client
Client
Solution: Another local cache layer & Preload CDN
(few CDNs have this feature, e.g. EdgeCast)
My
Tiny
Server

32. CPU vs TRAFFIC
• 13:53 preloaded post to CDN
• 13:55 PN sent
• 13:57+ traffic stops @ CDN servers, no CPU throughput
• 14:00 …

33. 14:00 Laugh a maniacal laugh of satisfaction

34. Summary
• CDN allows massive scale
• Smart CDN usage allows even more scale
• Scale + fresh content + low hosting prices is a
do-able mission
!
Questions?

35. Read More…
• Growing X20 without spending an extra penny on
hosting (The original blog post)
http://tech.ftbpro.com/post/78969626647/growing-x20-without-spending-an-extra-penny-on-hosting
• Single Page Applications Done Right
http://tech.ftbpro.com/post/84720180206/single-page-applications-done-right
• Count von Count - Real time counting DB
http://tech.ftbpro.com/post/73212710968/count-von-count-a-real-time-counting-database
• The Dark Side of Single Page Applications
http://tech.ftbpro.com/post/66182501420/the-dark-side-of-single-page-applications-rails
OSS: http://github.com/ftbpro
BLOG: http://tech.ftbpro.com