What does the Replication Factor determine in Cassandra?

The Replication Factor in Cassandra is crucial for determining how many copies of a given piece of data are stored across the nodes in a cluster. This number directly influences the durability and availability of the data. For example, if the replication factor is set to three, Cassandra will maintain three identical copies of the data across different nodes. This setup ensures that even if one or two nodes go down, the data can still be accessed from the remaining copies, enhancing fault tolerance and reliability in the system.

The other options relate to different aspects of database structure and performance but do not capture the essence of what Replication Factor specifically measures. While the number of tables and nodes, as well as the size of data centers, are relevant to the overall architecture of a Cassandra system, they do not define how many copies of data are stored. Understanding the Replication Factor is key to ensuring data is sufficiently replicated to meet your application’s availability and consistency requirements.