1. Beyond relational database
Building high performance website using
Redis and PHP
Pham Cong Dinh Hanoi PHP Day 2009
Software Developer December 19, 2009
Vega Corporation

2. What I am talking about
• Relational database in our world
• High performance web apps: new challenges
• Redis: A data structure store
• Using some of Redis's PHP clients
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Go beyond relational database 1st Qtr 2nd Qtr 3rd Qtr 4th Qtr

3. Relational database in our world
• Question
• How can we store our data?
• Answer
Part 1 • Relational database
• ACID is our love
• Atomicity - all parts of a transaction succeed or none of
then succeed. Integrity.
• Consistency - Nothing in your transaction will violate the
rules of the database. Integrity.
• Isolation - Each transaction operates independently of
every other transaction.
• Durability - Once the database says that data is
committed there is no opportunity for that to be undone.
Go beyond relational database

4. Relational database in our world
• Brewer's (CAP) Theorem
• C: Consistency - The client perceives that a set
of operations has occurred all at once.
• Strong consistency: ACID
• A: Availability - Every operation must terminate
in an intended response. Requests are to be
served even when there is a partition in the
cluster.
• P: Partition tolerance - Operations will
complete, even if individual components are
unavailable.
Go beyond relational database

5. Relational database in our world
• BASE: An ACID Alternative
• Basically Available
• Soft state
• Eventually consistent.
• Data partitioning and decision between
Consistency and Availability.
Go beyond relational database

6. Relational database in our world
• Relational database in high performance
environments
• Google
• Facebook
• Wikipedia
• Live Journal
• Yahoo
FAILED?
• … but most companies does not need
more than a single database server
• … but modern web apps today is facing a
real challenge
Go beyond relational database

7. High performance web apps: new
challenges
• Web server is bottleneck
Part 2
Go beyond relational database

8. High performance web apps: new
challenges
• Database is bottleneck
Go beyond relational database

9. High performance web apps: new
challenges
• CPU is bottleneck
Go beyond relational database

10. High performance web apps: new
challenges
• More requests: going distributed is easy
• Apache
• PHP
• Database scalability is hard
• Struggling with SMP: MySQL
• Replication is hard: replication is single
threaded: MySQL
• Most relational databases find hard to scale
WRITEs
• Schema constraints
• Disk I/O
• Memory constraints
• Global lock
• Complicated data types
Go beyond relational database

11. High performance web apps: new
challenges
• Scaling for READ is easier for scaling for
WRITE
mysql> select count(1) from setacc;
+----------+
| count(1) |
+----------+
| 3982438 |
+----------+
1 row in set (0.00 sec)
mysql> select count(1) from setacc_del;
+----------+
| count(1) |
+----------+
| 4003793 |
+----------+
1 row in set (0.00 sec)
Go beyond relational database

12. REDIS: A data structure datastore
• Redis (REmote DIctionary Server)
• Network interface to language dependent
client library: Python, Java, Ruby, Erlang,
Part 3 C# …
• Written in C
• Latest version: 1.1
Go beyond relational database

13. REDIS: A data structure datastore
• In a most basic form, it is a key – value
store: think Memcached
• Not memory only
• Not immediately durable
• Supports set of complicated data structure
• Can be found at
http://code.google.com/p/redis/
Go beyond relational database

14. REDIS: A data structure datastore
• Database concept
• SELECT index
Go beyond relational database

15. REDIS: A data structure datastore
• Key => Value
• SET mykey myvalue
• GET mykey
• More: MGET, MSET
•
Go beyond relational database

16. REDIS: A data structure datastore
• LIST
• RPUSH mylistkey string
• LPUSH mylistkey string
• LLEN mylistkey
• LPOP mylistkey
• RPOP mylistkey
• More: LGET/LSET ...
Go beyond relational database

17. REDIS: A data structure datastore
• SET
• SADD mysetkey member
• SREM key member
• Sorted SET
Go beyond relational database

18. Redis PHP clients
• Owlient's phpredis
• Can be found at
http://github.com/owlient/phpredis
Phần 4 • C extension
Go beyond relational database

19. Any question?
Phần 4
Go beyond relational database