he configuration parameter auto.leader.rebalance.enable in Apache Kafka determines whether automatic leader rebalancing is enabled or disabled. Leader rebalancing refers to the process of redistributing leadership of partitions across broker nodes in a Kafka cluster. The leader of a partition is responsible for handling read and write requests for that partition.

Here's what the configuration means:

If auto.leader.rebalance.enable=true:

Automatic leader rebalancing is enabled.

When a broker becomes unavailable or new brokers are added to the cluster, Kafka will automatically trigger leader rebalancing to ensure even distribution of leadership across available brokers.

This can help maintain cluster stability and performance by preventing situations where a few brokers are overloaded with leadership responsibilities while others are underutilized.

If auto.leader.rebalance.enable=false:

Automatic leader rebalancing is disabled.

Leader rebalancing will not be triggered automatically, even when brokers become unavailable or new brokers are added.

This configuration might be useful in scenarios where you want more control over when and how leader rebalancing occurs, or in cases where you're performing maintenance and don't want automatic rebalancing to interfere.

For example, in the server.properties configuration file of a Kafka broker, you might set: