cassandra_client

A 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

  • pluggable serialization and compression

  • Ruby 1.9 compatibility

This is an alpha release and does not yet support the full Thrift API.

Cassandra is a rapidly moving target; this library is currently tested against Cassandra trunk revision 789419.

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

Installation

You need Ruby 1.8 or 1.9, and Thrift.

If you don’t want to install Thrift from source, you can use this pre-packaged gem. Once you have Thrift, just run:

sudo gem install cassandra_client

Usage

Require the library:

require 'cassandra_client'

Connect to a server and keyspace:

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

Insert into a column family. You can insert a CassandraClient::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" => {"1" => ""}})

Query a super column:

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

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

See CassandraClient for more methods.

Reporting problems

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