I use the spring-kafka annotation @KafkaListener to designate my listener method.
I consume a single topic with a single partition. The messages are never more than one or two a second so a single thread is acceptable. The spring-kafka docs say the @KafkaListener defaults to using a ConcurrentMessageListenerContainer. Is the correct way to control concurrency by using setConcurrency?
Or, should I be somehow create a KafkaMessageListenerContainer, which is single threaded?
I currently use this:
@Bean("appContainerFactory")
KafkaListenerContainerFactory<ConcurrentMessageListenerContainer<Integer, String>>
kafkaListenerContainerFactory() {
ConcurrentKafkaListenerContainerFactory<Integer, String> factory = new ConcurrentKafkaListenerContainerFactory<>();
factory.setConcurrency(1);
...
}
Is the correct way to control concurrency by using setConcurrency?
What you have is correct, but the default concurrency
on the container is 1 so it's not necessary to specify it when you don't need concurrency.
Or, should I be somehow create a
KafkaMessageListenerContainer
, which is single threaded?
The concurrent container spins up a "child" KafkaMessageListenerContainer
for each concurrency
so just one is already created for you.