The scalability is described with technical details and a basic scenario.

1. XXL WEB
Seda Yalçın, Ömer Taşkın

2. ABOUT US, ABOUT YOU?
Seda Yalçın
Ömer Taşkın
Software
Engineer@GG
Software
Engineer@GG

3. OUTLINE
• WHY XXL WEB?
• What is Scalability in Theory?
• Scalability & Performance Issue
• How to scale?
• What is Scalability in Practice?
• Horizontal (Scale Out)
• Vertical (Scale Up)

4. WHY XXL WEB?
Scalability in WEB domain

5. XXL
web
What is scalability?
• What is scalability?
• What is not scalability?
• Scalability != performance, but..

6. XXL
web
Scalability & Performance
Only scalability does not increase the performance,
but increasing performance make scaling easier.

7. XXL
web
Scalability & Performance
Question: 100 room, 100 person
1- 1 P per room
2- 100 P in one room
What’s your choice?

8. XXL
web
Scalability & Performance

9. XXL
web
Language-oriented?
After 3 days + 10 min.. JJ Then, click ‘make it scalable’.

10. XXL
web
What can I do sometimes?
• Optimize your code,
• Design for scaling! “It won’t scale, if it’s not to scale”.
• A couple of language oriented examples.
• Performance is must for Scaling!
• Use caching Mechanisms
• And surely.. Scale your DB!

11. Caching Techniques
•
Store entire page
•
Store parts of a page
•
Store SQL queries
•
Store Complex Results
•
And Yours

12. Why Cache?
•
Kind a short-cut
•
Reducing number of requests
•
In fact, it’s for not scaling in DB layer
•
Ok, what if cache is burn out?
•
Then scale it!

13. That is not all..

14. Scalability @ DB Layer
With a basic example that shows DB things for scaling

15. A scaling scenario
• User actions should be logged.
• Probably records will be bigger than we guess.

16. A scaling scenario
•
Scalability Types
•
Horizontal (Scale Out)
•
Vertical (Scale Up)

17.
VERTICAL SCALABILITY (SCALE UP)
•
Adding resources to single node in a system
•
•
•
•
Bandwidth
Disc √
CPU
Memory

18. VERTICAL SCALABILITY (SCALE UP)
•
It’s not enough, isn’t it?

19. HORIZONTAL SCALABILITY (SCALE out)
•
Adding new node to system

20. HORIZONTAL SCALABILITY (SCALE out)
•
Need a sharding mechanism!

21. HORIZONTAL SCALABILITY (SCALE out)
•
First attempt:
Write your own sharding KK

22. HORIZONTAL SCALABILITY (SCALE out)

23. HORIZONTAL SCALABILITY (SCALE out)
Disadvantages of MySQL Cluster
• Does not supports add / remove node while cluster is up.
• Alter queries does not run on every node. Alter queries have to
run for every node.

24. HORIZONTAL SCALABILITY (SCALE out)
•
What we need?
• Have to be transactional?
• Must data be warranty?

25. HORIZONTAL SCALABILITY (SCALE out)
•
Second attempt
•
MongoDB!

26. HORIZONTAL SCALABILITY (SCALE out)

27. HORIZONTAL SCALABILITY (SCALE out)
•
Disadvantages of mongodb
• Does not supports transaction
• Does not supports data guarantee ( >= Mongo 1.8)

28. Wake Up!

29. Here we are!
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30. REFERANCES
http://www.oracle.com/technetwork/articles/dsl/white-php-part1-355135.html
http://docs.mongodb.org/manual/sharding/
http://dev.mysql.com/doc/refman/5.0/en/mysql-cluster.html
http://dev.mysql.com/doc/refman/5.0/en/mysql-cluster-limitations.html
http://bobiler.org
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