Cassandra is available for many systems, and in a variety of formats. These notes are for Cassandra 0.5x and Ubuntu 9.x.
First we need Java, Ant & Ivy:
See Java: Install OpenJDK, Ant & Ivy on Ubuntu Linux
Cassandra is written in Java and runs using Java.
Cassandra uses Ant and Ivy during the installation.
git clone git://git.apache.org/cassandra.git
groupadd cassandra
useradd cassandra -g cassandra -d /var/lib/cassandra -s /bin/false
sudo mkdir -p /var/log/cassandra
sudo chown -R cassandra /var/log/cassandra
sudo mkdir -p /var/lib/cassandra
sudo chown -R cassandra /var/lib/cassandra
ant -lib /usr/share/java/:/usr/lib/jvm/java-1.5.0-gcj-4.4/lib/