Cassandra Practice Test

What does the read repair mechanism do in Cassandra?

1. Maintains sync of data during read operations

2. Replicates data across nodes automatically

3. Improves write performance

4. Facilitates node failures

The correct answer is: Maintains sync of data during read operations

The read repair mechanism in Cassandra is designed to maintain the consistency of data across multiple replicas during read operations. When a client performs a read request, Cassandra retrieves data from the nodes responsible for the requested partition. If it detects discrepancies among the replicas, where some nodes return different data for the same query, read repair intervenes to reconcile these differences. During this process, Cassandra updates any outdated replicas with the most recent data from the isconsistently returned node. This ensures that all replicas eventually converge to the same value, preserving data consistency in the system. The mechanism plays a crucial role in maintaining the health and accuracy of the data as it grows and changes over time. The other options focus on different aspects of Cassandra’s architecture or functionality. While data replication is an essential feature of Cassandra, it is not the read repair mechanism itself. Improving write performance and handling node failures are part of Cassandra’s overall design and architecture but are not directly related to the specifics of how read repair functions. The primary focus of read repair is on maintaining synchronization of data across replicas during reads.