Kafka controller is a thread that runs inside only one broker in a Kafka cluster i.e. If we have a cluster of N brokers then there will be only one broker that is the controller.
It is like a brain for the cluster so that the cluster functions in a smooth and resilient way.
Whenever a Kafka Cluster is spun up, the brokers will first create a session with the zookeeper and the brokers will try to create an ephemeral node “/controller” inside the zookeeper. …
