Taking over the management of an EMR cluster which is created on demand and terminated after use I set about "tidying it up". Part of the tidy up was to simplify the installion of Apache Drill.
Any improvements greatfully accepted.
I abandoned the use of a bootstrap script on the cluster to install Drill as I wanted to use the default installation of Zookeeper.
Additionally the use of SSM meant that I could install and tune Drill after the cluster was created without the risk of the bootstrap failing and blocking cluster creation.
AWS says that SSM is installed "Amazon Linux base AMIs dated 2017.09 and later" (https://docs.aws.amazon.com/systems-manager/latest/userguide/sysman-install-ssm-agent.html).
I used the below to install it and ran this script as a bootstrap script on the EMR creation.
"bootstrap_for_ssm.bash"