If you are paying for Hadoop nodes that are not doing anything, then you are just burning money. There are ways you can batch up your workloads. Take an inventory of the jobs you have and tweak them to run in a batch mode and shutdown the cluster in-between those times. You can separate out clusters with auto-scaling instead of sizing and running it for all your workloads. You should shutdown the cluster when you can, to stop paying for it, unnecessarily. You can use Amazon Linux AMI with preinstalled customizations for faster cluster creation and use auto-scaling to minimize costs for long-running clusters.