What does “Tunable Consistency” allow developers to do in Cassandra?

Tunable consistency in Cassandra allows developers to define the level of consistency for operations, giving them control over how data is read and written across the distributed system. This means that when performing read or write operations, developers can choose the number of nodes that must acknowledge the operation before it is considered successful.

By adjusting this level, they can balance between consistency, availability, and partition tolerance based on the specific needs of their application. For example, a developer might require higher consistency for critical data by setting a higher number of acknowledgments, while for less critical data, they might opt for a lower level of consistency to enhance throughput and latency.

This feature is key in Cassandra’s design philosophy, providing flexibility to work with varying use cases, whether it’s for high availability or tighter consistency, thus empowering developers to optimize their applications effectively.