Whenever you're installing a new DataStaxApache Cassandra cluster, you need to remember to remove the user cassandra. We've seen this at a couple of customer installations now. If you do not change the user cassandra or at least alter the roles for the user cassandra....
Allcode has worked with DataStax, Inc. which is a data management company based in Santa Clara, California. Its product provides commercial support, software, and cloud database-as-a-service based on Apache Cassandra.