Cassandra Practice Test 2026 – Comprehensive All-in-One Guide to Exam Success!

The 'replication_factor' parameter in a keyspace defines the number of replicas for each piece of data. This means that when data is written to a keyspace, it is replicated across multiple nodes in the Cassandra cluster according to the specified replication factor. For example, if the replication factor is set to three, each piece of data will be stored on three different nodes. This mechanism enhances data availability and fault tolerance, ensuring that even if some nodes go down, the data can still be accessed from other nodes that hold the replicas.

The replication factor is crucial for maintaining consistency and durability in distributed systems like Cassandra. A higher replication factor offers better availability and data redundancy, while a lower factor can lead to higher performance and lower storage costs but at the risk of potential data loss in case of node failures. Understanding how replication works in Cassandra helps in designing resilient applications that can withstand failures without losing data access.