Kafka - InvalidTopicException when using multiple topics

Question

I have a SpringBoot application where I am using the @KafkaListener annotation with a topic and a groupId. I have two topics my listener needs to listen for. When listening for one topic, either one works fine

    @KafkaListener(topics = "topic1", groupId = "local")

or

    @KafkaListener(topics = "topic2", groupId = "local")

however, when I combine the two like this (which is my understanding of how to do multiple topics on one listener):

    @KafkaListener(topics = {"topic1,topic2"}, groupId = "local")

, I get scrolling exceptions like the following:

{
  "app": "myApp",
  "@timestamp": "2022-12-20T12:01:55.004Z",
  "userId": "",
  "hostname": "",
  "ipAddress": "",
  "logger": "org.apache.kafka.clients.Metadata",
  "level": "ERROR",
  "thread": "org.springframework.kafka.KafkaListenerEndpointContainer#0-0-C-1",
  "message": "[Consumer clientId=consumer-local-1, groupId=local] Metadata response reported invalid topics [topic1,topic2]",
  "class": "org.apache.kafka.clients.Metadata",
  "method": "checkInvalidTopics",
  "file": "Metadata.java",
  "line": 294
}
{
 "app": "myApp",
 "@timestamp": "2022-12-20T12:01:55.004Z",
 "userId": "",
 "hostname": "",
 "ipAddress": "",
 "logger": "org.apache.kafka.clients.consumer.internals.AbstractCoordinator",
 "level": "INFO",
 "thread": "org.springframework.kafka.KafkaListenerEndpointContainer#0-0-C-1",
 "message": "[Consumer clientId=consumer-local-1, groupId=local] Rebalance failed.",
 "class": "org.apache.kafka.clients.consumer.internals.AbstractCoordinator",
 "method": "joinGroupIfNeeded",
 "file": "AbstractCoordinator.java",
 "line": 470,
 "stack": "org.apache.kafka.common.errors.InvalidTopicException: Invalid topics: [topic1,topic2]\n"

}

Any ideas on what I am doing wrong are greatly appreciated. Thank you

Answer 1

You can listen to multiple topics in the same @KafkaListener by passing them in a comma separated object. In your case it should be

@KafkaListener(topics = {"topic1", "topic2"}, groupId = "local")

Answer 2

Try this:

{"topic1", "topic2"}