The following is the opening paragraphs for discussion RavenDB 4.0 clustering and distribution model in the Inside RavenDB 4.0 book.
You might be familiar with the term "murder of crows" as a way to refer to a group for crows. It has been used in literature and arts many times. Of less reknown is the group term for ravens, which is "unkindness". Personally, in the name of all ravens, I'm torn between being insulted and amused.
Professionally, setting up RavenDB as a cluster on a group of machines is a charming exercise (however, that term is actually reserved for finches) that bring a sense of exaltation (taken too, by larks) by how pain free this is. I'll now end my voyage into the realm of ornithology's etymology and stop speaking in tongues.
On a more serious note, the fact that RavenDB clustering is easy to setup is quite important, because it means that it is much more approachable.
 If you are interested in learning why, I found this answer fascinating
It was amusing to write, and it got me to actually start writing that part of the book. Although I’m not sure if this will survive editing and actually end up in the book.