I think the questions was "is this complexity necessary?" If the same (deployment and upgrades for production, staging and testing environments, for any number

I think the questions was "is this complexity necessary?" If the same (deployment and upgrades for production, staging and testing environments, for any number of hosts) could be achieved with a small shell script - doesn't this mean that cluster thing isn't really useful? I think a lot of "real" projects (smaller ones) work perfectly well without any complicated cluster management tools, and aren't really hindered by lack of what those offer.