There are many considerations when choosing a replication factor, including availability, performance, and consistency. Since our topic is high availability, let's presume your desire is to maintain data availability in the case of node failure.
It's important to understand exactly what your failure tolerance is, and this will likely be different depending on the nature of the data. The definition of failure is probably going to vary among use cases as well, as one case might consider data loss a failure, whereas another accepts data loss as long as all queries return.
Achieving the desired availability, consistency, and performance targets requires coordinating your replication factor with your application's consistency level configurations. In order to assist you in your efforts to achieve this balance, let's consider a single data center cluster of 10 nodes and examine the impact of various configuration combinations, replication factor...
