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.