This document discusses building scalable web applications. It defines scalability as the ability of a system to handle growing workloads in a capable manner or to be enlarged to accommodate growth. There are two types of scalability: vertical, which involves making individual components more powerful; and horizontal, which involves adding more components. The document uses examples like YouTube and Twitter to show how startups need to plan for scalability to accommodate rapid growth, as they may experience 10-100x increases in users within a year. It provides strategies for scaling out non-scalable apps, such as adding caching, separating databases from apps, and using load balancers and clusters.

1. BUILDING SCALABLE
WEB APPS

2. ABOUT ME
Matías E. Fernández @matiasfrndz
Head of Systems and Development

3. WHAT DOES
“SCALABLE” MEAN?

4. ≠ efficient usage of CPU
≠ efficient usage of bandwidth
≠ efficient usage of storage
≠ fast page loads in browser
SCALABILITY ≠ PERFORMANCE

5. WTF?

6. SCALABILITY
In electronics (including hardware,
communication and software), scalability is
the ability of a system, network, or process
to handle a growing amount of work in a
capable manner or its ability to be
enlarged to accommodate that growth.
en.wikipedia.org/wiki/Scalability

7. VERTICAL VS.
HORIZONTAL
SCALABILITY

8. VERTICAL SCALING
Bigger, faster, stronger!

9. HORIZONTAL SCALING
Start small …

10. HORIZONTAL SCALING

11. HORIZONTAL SCALING
Think BIG!

12. WHY BOTHER?
Because web startups tend to die
or grow … really big!

13. EXAMPLES

14. YOUTUBE
• Founded in 2005 in a garage
• Officially launched in December 2005 with
8 million videos watched per day
• 100 million views a day in July 2006
• Over 4 Billion videos viewed per day in
January 2012
• 72 hours of video uploaded every minute
in May 2012
x 12 in
7 month!

15. YOUTUBE
1 mio
10 mio
100 mio
1'000 mio
10'000 mio
2005
2006
2012
YouTube videos watched per day
Notice the logarithmic scale, bro?

16. TWITTER
• Founded in March 2006
• Officially launched in July 2006
• 400’000 tweets per quarter in 2007
• 100 million tweets per quarter in 2008
• 65 million tweets per day in June 2010
• 140 million tweets per day in March
2011, 1’600 tweets per second
x 230 in
12 month!

17. TWITTER
1'000
10'000
100'000
1'000'000
10'000'000
100'000'000
2007
2008
2010
Tweets per day
Recognise the scale?

18. BETTER BE PREPARED
Rewriting your web app to be scalable
and
at the same time scale it to accommodate
a 10 to 100 fold of customers
in 12 month?
Sounds like a challenge!

19. PLAYING FOR TIME
Strategies to Scaling out a Non-Scalable Web App
Semi

20. KEEP THINGS SIMPLE
Add caching reverse proxy to reduce the
load on your web app and server
HTTP Accelerator

21. WE ALL START SMALL
Separate database and app server to gain
CPU and I/O-performance
App Server
Database Server

22. LET’S START THE PARTY
App Servers
Redundant Load Balancer
w. HTTP Acc.
We still need
our database

23. SCALE OUT
vertically
vertically
horizontally

24. SINGLE POINT OF FAILURE
They call me single point
of failure

25. REDUCE SPOF
2-Node Failover
Cluster highly availability
✔

26. Kundenname, Präsentationstitel
Nine Internet Solutions AG
Albisriederstr. 243a
CH-8047 Zürich
Tel +41 44 637 40 00
Fax +41 44 637 40 01
info@nine.ch
QUESTIONS?

27. Kundenname, Präsentationstitel