Developing Solutions for Microsoft Azure (AZ-204) Practice Exam

Which consistency level in Azure Cosmos DB offers the greatest throughput?

1. Strong

2. Session

3. Eventual

4. Bounded Staleness

The correct answer is: Eventual

The consistency level that offers the greatest throughput in Azure Cosmos DB is Eventual consistency. This level of consistency allows for the highest performance because it does not require immediate synchronization of data across all replicas. Instead, it permits clients to read stale data, which means that the system can process read and write operations more quickly, thus enhancing throughput. By prioritizing availability and partition tolerance over immediate consistency, Eventual consistency accepts that data may not be current at the moment a read operation occurs. This less stringent requirement results in lower latency for read and write operations, making it suitable for scenarios where high throughput is essential and it is acceptable for the application to work with slightly outdated information. This characteristic makes Eventual consistency particularly beneficial in applications that can tolerate some level of data inconsistency in exchange for faster performance, such as social media feeds or sensor data processing. In contrast, Strong consistency requires that all replicas are up-to-date before a read operation can occur, which can significantly reduce throughput due to the additional overhead involved in achieving this level of synchronization. Bounded Staleness permits a specified delay in data consistency, and this can still introduce some latency compared to Eventual consistency. Session consistency, while providing a good balance of consistency and performance, still can’t match