we have cluster with 12 Kafka machines and 3 zookeeper servers on Linux servers
- Kafka version is 2.7 version , ( broker and controller are co-hosted on the same PID )
as known Kafka have 2 important logs and they are **server.log** and **controller.log**
about **controller.log** , when we look on this log we can see the following words - "`Shutdown completed`" in the log
[2024-08-20 21:42:01,582] INFO [ControllerEventThread controllerId=1001] Shutdown completed (kafka.controller.ControllerEventManager$ControllerEventThread)
the first thinking when we see the messages about "`Shutdown completed`" - is like this message is "bad" and why controller stopped ...
but when we look on all machines most of the machines have this message as - `Shutdown completed` (`kafka.controller.ControllerEventManager$ControllerEventThread`)
**but on other hand** only one controller should be active from all brokers and maybe the messages as "`Shutdown completed`" are only indicate that controllers that are not active are in standby state and therefore are in state of - `Shutdown completed` ?
for example - here one of the log from one broker machine
[2024-08-20 21:23:18,084] DEBUG [Controller id=1001] Broker 1007 was elected as controller instead of broker 1001 (kafka.controller.KafkaController)
org.apache.kafka.common.errors.ControllerMovedException: Controller moved to another broker. Aborting controller startup procedure
[2024-08-20 21:33:51,281] DEBUG [Controller id=1001] Broker 1005 was elected as controller instead of broker 1001 (kafka.controller.KafkaController)
org.apache.kafka.common.errors.ControllerMovedException: Controller moved to another broker. Aborting controller startup procedure
[2024-08-20 21:42:01,581] INFO [ControllerEventThread controllerId=1001] Shutting down (kafka.controller.ControllerEventManager$ControllerEventThread)
[2024-08-20 21:42:01,582] INFO [ControllerEventThread controllerId=1001] Shutdown completed (kafka.controller.ControllerEventManager$ControllerEventThread)
[2024-08-20 21:42:01,582] INFO [ControllerEventThread controllerId=1001] Stopped (kafka.controller.ControllerEventManager$ControllerEventThread)
[2024-08-20 21:42:01,582] DEBUG [Controller id=1001] Resigning (kafka.controller.KafkaController)
[2024-08-20 21:42:01,583] DEBUG [Controller id=1001] Unregister BrokerModifications handler for Set() (kafka.controller.KafkaController)
[2024-08-20 21:42:01,604] INFO [PartitionStateMachine controllerId=1001] Stopped partition state machine (kafka.controller.ZkPartitionStateMachine)
[2024-08-20 21:42:01,608] INFO [ReplicaStateMachine controllerId=1001] Stopped replica state machine (kafka.controller.ZkReplicaStateMachine)
[2024-08-20 21:42:01,608] INFO [Controller id=1001] Resigned (kafka.controller.KafkaController)
[2024-08-20 21:43:45,196] INFO [ControllerEventThread controllerId=1001] Starting (kafka.controller.ControllerEventManager$ControllerEventThread)
[2024-08-20 21:43:45,208] DEBUG [Controller id=1001] Broker 1005 has been elected as the controller, so stopping the election process. (kafka.controller.KafkaController)
[2024-08-20 21:52:28,400] DEBUG [Controller id=1001] Broker 1001 was elected as controller instead of broker 1001 (kafka.controller.KafkaController)
org.apache.kafka.common.errors.ControllerMovedException: Controller moved to another broker. Aborting controller startup procedure
<---- LOG IS ENDED HERE
so the question is - can we ignore the messages as `INFO [ControllerEventThread controllerId=1001] Shutdown completed (kafka.controller.ControllerEventManager$ControllerEventThread)`
of maybe something is wrong with the Kafka controller ?
Michael-Bronson
