Closed
Description
Expected Behavior
Assume we have following settings:
application.properties
spring.kafka.listener.ack-mode=count
spring.kafka.listener.ack-count=100
logging.level.org.springframework.kafka=debugExpect to commit offset every 100 messages processed
SpringBoot Application:
@RestController
@SpringBootApplication
public class SpringKafkaDemo2Application {
public static void main(String[] args) {
SpringApplication.run(SpringKafkaDemo2Application.class, args);
}
@KafkaListener(id = "fooGroup", topics = "topic")
public void listen(ConsumerRecord<String, String> record) throws Exception {
}
@Autowired
private KafkaTemplate<Object, Object> template;
@PostMapping(path = "/send/{what}")
public void sendFoo(@PathVariable String what) {
for (int i = 0; i < 500; i++) {
this.template.send("topic", "message" + i);
}
}
}Current Behavior
Committing the offset every time after 500 records processed:
2023-07-06T18:07:36.680+08:00 DEBUG 26195 --- [ fooGroup-0-C-1] o.s.k.l.KafkaMessageListenerContainer : Committing in COUNT because count 500 exceeds configured limit of 100
2023-07-06T18:07:36.680+08:00 DEBUG 26195 --- [ fooGroup-0-C-1] o.s.k.l.KafkaMessageListenerContainer : Commit list: {topic-0=OffsetAndMetadata{offset=560, leaderEpoch=null, metadata=''}}
2023-07-06T18:07:36.680+08:00 DEBUG 26195 --- [ fooGroup-0-C-1] o.s.k.l.KafkaMessageListenerContainer : Committing: {topic-0=OffsetAndMetadata{offset=560, leaderEpoch=null, metadata=''}}Context
Although the larger the ackCount, the better the performance, but it will increase the chance of retransmission, so sometimes it is useful for the ackCount to be smaller than maxPollRecords