Scaling CouchDB by Bradley Holt, published by O’Reilly, is a sweet little book.
Buy this book if you’re using, or contemplating using, CouchDB in a high-performance setting. It’s only 58 pages. But it’s a very good 58 pages.
Scaling CouchDB
Published
Seek Nuance 
Does it tell you how to make the thing HA/redundant in setup against failures? From all appearances, it seems to be quite the bitch – especially for n+1 nodes where n>2
Not as such, no. It goes into how to set up replication, and touches on some HA concerns, but it doesn’t delve into failure recovery in detail.