The following commands install Whirr and start a 3 node ZooKeeper cluster on Amazon EC2 in 5 minutes or less. You need to have Java 6 and an SSH client already installed. Help on finding your AWS credentials can be found in the FAQ.
export WHIRR_PROVIDER=aws-ec2
export WHIRR_IDENTITY=$AWS_ACCESS_KEY_ID
export WHIRR_CREDENTIAL=$AWS_SECRET_ACCESS_KEY
# or create ~/.whirr/credentials similar to conf/credentials.sample
curl -O http://www.apache.org/dist/whirr/whirr-0.8.0/whirr-0.8.0.tar.gz
tar zxf whirr-0.8.0.tar.gz; cd whirr-0.8.0
ssh-keygen -t rsa -P '' -f ~/.ssh/id_rsa_whirr
bin/whirr launch-cluster --config recipes/zookeeper-ec2.properties --private-key-file ~/.ssh/id_rsa_whirr
echo "ruok" | nc $(awk '{print $3}' ~/.whirr/zookeeper/instances | head -1) 2181; echo
Upon success you should see imokechoed to the console, indicating that ZooKeeper is running.
You can shut down the cluster with
bin/whirr destroy-cluster --config recipes/zookeeper-ec2.properties --private-key-file ~/.ssh/id_rsa_whirr
The various options are explained in more detail in the Quick Start Guide.