kafka集成zookeeper，使用最新kafka-client，自动提交，测试异常情况，数据未丢失？

Question

如题和下面consumer代码片段：

Properties props = new Properties();
props.put("bootstrap.servers", "192.168.83.20:9092");
props.put("metadata.broker.list", "192.168.83.20:2181");
props.put("group.id", "default1");
props.put("enable.auto.commit", "true");
props.put("auto.commit.interval.ms", "1000");
props.put("session.timeout.ms", "30000");
props.put("key.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
props.put("value.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
KafkaConsumer<String, String> consumer = new KafkaConsumer<String, String>(props);
consumer.subscribe(Arrays.asList("top1"));
final int minBatchSize = 1;
List<ConsumerRecord<String, String>> buffer = new ArrayList<>();
System.out.println("进入了......");
while (true) {
  ConsumerRecords<String, String> records = consumer.poll(100);
  for (ConsumerRecord<String, String> record : records) {
   System.out.println("进入了......records");
	  buffer.add(record);
   try {
		Thread.sleep(1000); //到这个地方的时候过大概4、5s,把consumer停掉
		System.out.println("进入了......records--1000---");
		Thread.sleep(20000);
	} catch (Exception e) {
		e.printStackTrace();
	}
	  System.out.println("fetched from partition " + record.partition() + ", offset: " + record.offset() + ", message: " + record.value());  
  }
//          consumer.commitAsync();
}

 就是producer发送消息 。然后consumer端接受消息，consumer里让当前操作睡眠20s， 在consumer接收到消息5s左右，把consumer停掉。设置自动提交，而且时间是1s，经测试发现数据未丢失，什么情况 ? 

Answer 1

代码和你描述没看太懂，不过consumer停不停跟收到数据没有什么关系。kfk默认保存7天的数据，停这一会儿，在重启consumer后肯定会收到数据