Apache Whirr is a set of libraries for running cloud services. You can use Whirr to run CDH4 clusters on cloud providers' clusters, such as Amazon Elastic Compute Cloud (Amazon EC2). There's no need to install the RPMs for CDH4 or do any configuration; a working cluster will start immediately with one command. It's ideal for running temporary Hadoop clusters to carry out a proof of concept, or to run a few one-time jobs. When you are finished, you can destroy the cluster and all of its data with one command.
If you have not already done so, install Cloudera's yum, zypper/YaST or apt repository before using the following commands to install or update Whirr. For instructions, see CDH4 Installation.