When using internal security with Cassandra, what replication factor do you use for system_auth?
The older docs seem to suggest it should be N, where N is the number of nodes, while the newer ones suggest we should set it to a number greater than 1. I can understand why it makes sense for it to be higher - if a partition occurs and one section doesn't have a replica, nobody can log in.
However, does it need to be all nodes? What are the downsides of setting it to all ndoes?