You must have a Hadoop cluster (single-node experimental or multinode production) up and running to install Impala on it or already have Impala installed on it. Cloudera CDH 4.3 or above is preferred to install Impala. If you decide to install Cloudera Impala in your Hadoop Cluster, you can download it from the following link:

https://www.cloudera.com/content/support/en/downloads/download-components.html

If you do not have an active Hadoop cluster and still want to learn and try Impala, you have the option of downloading a Cloudera QuickStart Virtual Machine including everything from Cloudera, at the following link:

https://www.cloudera.com/content/support/en/downloads.html