Apache Kafka Practice Exam 2025 – The Complete All-in-One Guide for Exam Success!

Using acks set to 1 means that the producer receives an acknowledgment from the leader broker once the message is successfully written to the leader's local log. This configuration prioritizes throughput and lower latency, as the producer does not wait for acknowledgments from followers or ensure that messages are safely replicated to other brokers.

The implication of this setting is that if the leader crashes after acknowledging the message, but before the message has been replicated to any of the follower brokers, that message could be lost. The leader's acknowledgment means that the message is only guaranteed to be available in the leader's log and is not guaranteed to be present in the replicas. Therefore, this configuration can lead to situations where messages are not reliably stored across the cluster, underscoring the matching concern regarding potential message loss in the event of a leader failure.

The other options reflect different aspects of producer acknowledgment settings. For example, acknowledging messages from all replicas or requiring that messages are synced to disk before acknowledgment provides greater reliability and durability, while acks=1 sacrifices some of that reliability for speed and efficiency.