Conquer Apache Kafka 2025 – Dive into Data Streaming Dominance!

A topic with a replication factor of 3 indicates that each partition of that topic will have 3 copies across different brokers. This is essential for ensuring data durability and availability. When a partition is replicated 3 times, it helps protect the data against broker failures, as the system can continue to serve requests if one or even two of the brokers go down.

Having multiple replicas also allows for load balancing when consuming data, as consumers can read from different brokers. This redundancy ensures that if one broker is unavailable, other brokers will still have a copy of the partition data, thereby supporting fault tolerance.

In contrast, replicating each partition 2 times would imply a replication factor of 2, which does not provide the same level of redundancy. Storing all messages in only one broker would negate the benefits of replication entirely, rendering the system vulnerable to data loss if that broker fails. Lastly, while the idea that every broker keeps its own copy might suggest that multiple copies exist, it does not accurately represent the intended functioning of Kafka's replication, where only a subset of brokers hold replicas, not every broker holding all copies. Thus, the correct understanding of a replication factor of 3 is that each partition is indeed replicated 3 times across various brokers