I like having stuff high available. Everybody who works in IT knows it: Everything can fail and it most likely fails when you really need it as written in Murphy's law: "Anything that can go wrong will go wrong". Therefore I decided to cluster my UniFi Controller today. For sure it does not need to run on a server and can be started locally for configuration. But I like to have some nice stats and graphs which are also provided by the Controller and therefore it needs to be up and running constantly.