Glossary

Replication factor (Kafka)

The Kafka replication factor (RF) determines how many brokers store a copy of each partition. With RF=3, there is one leader and two followers per partition. The leader handles reads and writes; followers fetch from the leader to stay in sync. A higher RF provides greater durability (survive N−1 broker failures) but multiplies storage cost and replication network traffic by RF.

Formula: For acks=all, produce latency includes cross-AZ RTT to followers; size replica.fetch.max.bytes ≥ message.max.bytes.

Last updated: March 2026