When restarting all of the Kafka servers (e.g. a periodic patch and reboot), it is better if you avoid rolling the controller between the nodes on every reboot. To accomplish this goal, find out which server is acting as the controller and restart it last — you’ll have the controller move one time using this method, but only once no matter how many servers are in your deployment.

# Connect to zookeeper
./zookeeper-shell.sh localhost:2181
# Find controller by opening the zookeeper shell and querying for controller
get /controller
{"version":1,"brokerid":250,"timestamp":"1676694139851"}

# Get details on broker ID reported as controller
get /brokers/ids/250
{"listener_security_protocol_map":{"PLAINTEXT":"PLAINTEXT","SASL_PLAINTEXT":"SASL_PLAINTEXT"},"endpoints":["PLAINTEXT://kafkahost.example.net:9093","SASL_PLAINTEXT://kafkahost.example.net:9092"],"jmx_port":9999,"host":"kafkahost.example.net","timestamp":"1676348503278","port":9093,"version":4}