Cassandra Practice Test

What does a high replication factor contribute to in a Cassandra cluster?

1. Improved performance during read operations

2. Increased write latency

3. Greater redundancy of data

4. All of the above

The correct answer is: Greater redundancy of data

A high replication factor in a Cassandra cluster significantly contributes to the greater redundancy of data. When the replication factor is increased, each piece of data is stored on multiple nodes within the cluster. This redundancy means that if one or more nodes fail, the data can still be accessed from the remaining nodes holding copies, thus enhancing data availability and fault tolerance. Increased redundancy also allows for improved recovery capabilities in case of hardware failures or network issues, ensuring that data remains consistent and accessible to users, even in adverse conditions. This is a key benefit of using a distributed database like Cassandra, where high availability is essential. While a higher replication factor can improve read performance under certain conditions by allowing more nodes to serve read requests, it is primarily associated with ensuring data durability and availability. It’s important to note that higher replication can also lead to increased write latency, as data must be written to multiple nodes. Therefore, while other effects can occur because of a high replication factor, its biggest contribution is indeed the added redundancy of data.