Apache Kafka Practice

In a Kafka setup, if a broker fails, the system's resilience is largely attributed to its built-in replication mechanism. When data is stored in Kafka, it can be replicated across multiple brokers, which ensures that there are copies of each partition on different brokers. If one broker fails, the remaining brokers that have replicas of the affected partitions can continue to service requests.

This design allows consumers to keep processing messages from the replicated partitions on the operational brokers. As long as there are sufficient replicas available (determined by the replication factor set for the topic), consumers can continue reading data without interruption, thus maintaining system availability.

The other options present scenarios that do not accurately reflect the system's behavior during a broker failure. For example, messages are not lost permanently as long as they are replicated elsewhere, consumers do not automatically stop processing messages if there’s an available replica, and producers can still publish messages to the remaining operational brokers, provided they have access to them. This fault tolerance is a key feature of Kafka, ensuring robustness and reliability in distributed systems.