Which component is responsible for establishing connection and registration between Kafka brokers?

In Kafka, the component responsible for establishing connections and registration between brokers is ZooKeeper. It coordinates the cluster's operation, stores metadata about brokers and topics, monitors broker status, and assists in leader election for partitions.

Starting from Kafka 2.8, there is an option to operate without ZooKeeper, using its own coordination mechanism based on KRaft (Kafka Raft), but traditionally, ZooKeeper performs this role.