For an overview of Mahout, please refer Apache Mahout – Machine Learning for Big Data.

Installation

As mentioned in the overview, Mahout is an open source scalable machine learning library. It is recommended that Mahout runs on top of Hadoop when processing large amounts of data. It is sufficient to install Mahout only on the Hadoop master node.

Before installing Mahout,  ensure that Hadoop is installed in any of the modes. For the purposes of this blog, install Hadoop in cluster mode. Proceed with these commands in the same order -

user1@ubuntu-server:~$ apt-get install maven2

user1@ubuntu-server:~$ cd /opt

user1@ubuntu-server:~$ svn co http://svn.apache.org/repos/asf/mahout/trunk

user1@ubuntu-server:~$ mv trunk mahout_trunk

user1@ubuntu-server:~$ ln -s mahout_trunk/ mahout

user1@ubuntu-server:~$ cd mahout

user1@ubuntu-server:~$ mvn install

P.S.: Sometimes some tests fail while building mahout from source. In such cases use – user1@ubuntu-server:~$ mvn -DskipTests install

Edit .bash_profile to add entry for $MAHOUT_HOME, $HADOOP_CONF_DIR and change $PATH

vim ~/.bash_profile

• export HADOOP_CONF_DIR=$HADOOP_HOME/conf
• export MAHOUT_HOME=/opt/mahout
• export PATH=$PATH:$MAHOUT_HOME

Logout and login for the changes to take effect. After successful login, typing echo $MAHOUT_HOME should print /opt/mahout on the console.

That’s it! Mahout is installed successfully. Let’s play around.

For more details, please refer the following links -

https://cwiki.apache.org/confluence/display/MAHOUT/BuildingMahout