You need to create a ConcurrentKafkaListenerContainerFactory and set the concurrency parameter. It creates 1 or more KafkaMessageListenerContainers based on concurrency. If the ContainerProperties is configured with TopicPartitions, the TopicPartitions are distributed evenly across the instances.
For example
ConcurrentKafkaListenerContainerFactory<String, String> factory = new ConcurrentKafkaListenerContainerFactory<>();
factory.setConcurrency(12);
If you are using
@KafkaListener, it has had aconcurrencyproperty (since 2.2) which overrides the container factory's default setting.In this case, the clientId is generated dynamically for each listener ?