cassandra

A Ruby client for the Cassandra distributed database.

License

Copyright 2009 Twitter, Inc. See included LICENSE file. Portions copyright 2004-2009 David Heinemeier Hansson, and used with permission.

The public certificate for this gem is here.

Features

• clean encapsulation of the Thrift API

• compatible UUID and Long classes, for GUID generation

• Ruby 1.9 compatibility

The Github source repository is here. Patches and contributions are very welcome.

Installation

You need Ruby 1.8 or 1.9. If you have those, just run:

sudo gem install cassandra

Cassandra itself is a rapidly moving target. In order to get a working server, use the bin/cassandra_helper script:

cassandra_helper cassandra

A server will be installed in $HOME/cassandra/server, and started in debug mode.

Usage

Now, start IRb and require the library:

require 'cassandra'

Connect to a server and keyspace:

client = Cassandra.new('Twitter', "127.0.0.1")

Insert into a column family. You can insert a Cassandra::OrderedHash, or a regular Hash, if order doesn’t matter:

client.insert(:Users, "5", {'screen_name' => "buttonscat"})

Insert into a super column family:

client.insert(:UserRelationships, "5", {"user_timeline" => {UUID.new => "1"}})

Query a super column:

timeline = client.get(:UserRelationships, "5", "user_timeline")

The returned result will always be a Cassandra::OrderedHash.

See Cassandra for more methods.

Further reading

• Up and Running With Cassandra

Reporting problems

The Github issue tracker is here. If you have problems with Cassandra itself, please use the cassandra-user mailing list.