I did not understand this completely: (Quorum)
- R=1 and W=N ⇒ full replication (write-all, read-one): undesirable when servers can be unavailable because writes are not guaranteed to complete.
N = nodes in the quorum group
W = minimum write nodes
R = minimum read nodes
Writes are not guaranteed, because all N should commit and even 1 is down then it will not commit and complete a transaction.
BUT, if we read from 1 node, what happens if that node is down. This looks a more dangerous situation as it becomes ‘unavailable’.