By default, Cassandra does not require user authentication when clients connect to the cluster, and it also does not place any restriction on the ability of clients to perform operations on the database. To change this, we will need to make a couple of minor modifications to our Cassandra instance's configuration file. Since modifications to the configuration file are typically a concern of deployment engineers, we haven't interacted with it in this book, so you may be wondering where to find it. Where it's located depends on your platform; the table below assumes you installed Cassandra using the instructions for your platform in the Installing Cassandra section of Chapter 1, Getting Up and Running with Cassandra. The following table gives you the location of the cassandra.yaml file on the respective platforms.
| Platform | Configuration file location |
