The mechanism to define a data center depends on the snitch that you specify in cassandra.yaml. Take a look at the previous chapter if you need a refresher on the various types of snitches. You'll recall that the snitch's role is to tell Cassandra what your network topology looks like, so it can know how to place replicas across your cluster. While configuring a snitch, it's important to make sure that the host names resolved by the snitch match those in your schema.
With this in mind, let's take a closer look at what configuration looks like for each of the snitch options.
There really isn't any configuration to be performed on RackInferringSnitch, as long as your IP addressing scheme matches your topology. Specifically, it uses the second, third, and fourth octets to define data center, rack, and node, respectively, as follows:
This strategy can work well for simple deployments in physical data centers where IP addresses can be predicted reliably. The...