If you use configuration management already (Puppet, Chef, Ansible), you can skip this tip.

If you don’t use configuration management tools yet, you should! Managing a handful of servers by parallel-ssh may work now, but it will become a nightmare as you grow your cluster. It is almost impossible to edit 30 configuration files by hand without making a mistake.

Configuration management tools help make your cluster consistent by automating the process of config changes. It may take a little time to set up and learn, but it will pay itself off handsomely over time.