1. An introduction to Cassandra
London Web Meetup 20/1/2011
Dave Gardner @davegardnerisme

2. Plug
Regular Cassandra meetup at Skills Matter near Old Street.
Monday 21st February. Free beer! Free pizza!
http://meetup.com/Cassandra-London
3. What is Cassandra?
4. Cassandra is a distributed,fault-tolerant, scalable, column-oriented data store
More on this in a minute
5. Who is using Cassandra?
6. 7. Why might you want to use a distributed,fault-tolerant, scalable, column-oriented data store?
8. Collecting preferences
9. Recommendations
The Tweeted Times
10. Social graphs
11. Thats a lot of nuts
http://www.flickr.com/photos/swamibu/3520926105/sizes/o/
12. Why Cassandra?
13. Cassandra is a distributed,fault-tolerant, scalable, column-oriented data store
14. #1
#6
#2
No master node (no single point of failure)
#3
#5
Client
#4
15. Cassandra is a distributed,fault tolerant, scalable, column-oriented data store
16. Replication Factor = 3
#1
#6
#2
#3
#5
Client
#4
17. Key feature!
Cassandra hastunable consistency
(on a per-request basis)
18. Consistency level: how many replicas must respond to declare success?
Plus some DC aware levels
19. Cassandra is a distributed,fault-tolerant, scalable, column-oriented data store
20. Key feature!
Scales linearly for both reads and writes
(horizontally)
21. Cassandra is particularly suited to use-cases that have a high write load
22. Cassandra is a distributed,fault-tolerant, scalable, column-oriented data store
23. {foo => {bar => baz}}
{key => {col_name => col_value}}
24. {
column_family => {
key => {
col_name => col_value
}
}
}
25. That was a very brief overview
Learn more at Cassandra London!
26. Thank you! Any questions?
Dave Gardner @davegardnerisme
Cassandra London @cassandralondon
http://meetup.com/Cassandra-London
27. Further reading for the keen ones
WTF is a SuperColumn? An Intro to the Cassandra Data Modelhttp://arin.me/blog/wtf-is-a-supercolumn-cassandra-data-model
Clients list (Python, Java, .NET, Ruby, PHP)http://wiki.apache.org/cassandra/ClientOptions
Cassandra docs on DataStax websitehttp://www.datastax.com/docs/0.7/index
Introduction to Cassandra by Aaron Mortonhttp://www.slideshare.net/aaronmorton/well-railedcassandra24112010-5901169
Operations and troubleshooting guide by Ben Blackhttp://www.slideshare.net/benjaminblack/cassandra-summit-2010-operations-troubleshooting-intro
28. More reading for the really keen
Introduction to Cassandra: Replication and Consistency by Ben Blackhttp://www.slideshare.net/benjaminblack/introduction-to-cassandra-replication-and-consistency
Running Cassandra on Amazon EC2 by Dave Gardnerhttp://www.slideshare.net/davegardnerisme/running-cassandra-on-amazon-ec2
4 Months With Cassandra, a love story by CloudKickhttps://www.cloudkick.com/blog/2010/mar/02/4_months_with_cassandra/
Cassandra London meetuphttp://meetup.com/Cassandra-London