我想测试一个Kafka的例子。我使用的是Kafka0.10.0.1制作人:
object ProducerApp extends App {
val topic = "topicTest"
val props = new Properties()
props.put("bootstrap.servers", "localhost:9092")
props.put(ConsumerConfig.GROUP_ID_CONFIG, "consumer")
props.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer")
props.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer")
val producer = new KafkaProducer[String, String](props)
for(i <- 0 to 20)
{
val record = new ProducerRecord(topic, "key "+i," value "+i)
producer.send(record)
Thread.sleep(100)
}
}
使用者(主题“topictest”由1个分区创建):
object ConsumerApp extends App {
val topic = "topicTest"
val properties = new Properties
properties.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092")
properties.put(ConsumerConfig.GROUP_ID_CONFIG, "consumer")
properties.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, "false")
properties.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest")
properties.put("key.deserializer", "org.apache.kafka.common.serialization.StringDeserializer")
properties.put("value.deserializer", "org.apache.kafka.common.serialization.StringDeserializer")
val consumer = new KafkaConsumer[String, String](properties)
consumer.subscribe(scala.List(topic).asJava)
while (true) {
consumer.seekToBeginning(consumer.assignment())
val records:ConsumerRecords[String,String] = consumer.poll(20000)
println("records size "+records.count())
records.asScala.foreach(rec => println("offset "+rec.offset()))
}
}
问题是,使用者在第一次迭代时并没有从偏移量0读取数据,而是在其他迭代时读取数据。我想知道原因,以及如何让使用者在所有迭代中读取偏移量0。预期结果是:
records size 6
offset 0
offset 1
offset 2
offset 3
offset 4
offset 5
records size 6
offset 0
offset 1
offset 2
offset 3
offset 4
offset 5
...
但得到的结果是:
records size 4
offset 2
offset 3
offset 4
offset 5
records size 6
offset 0
offset 1
offset 2
offset 3
offset 4
offset 5
...
1条答案
按热度按时间envsm3lx1#
我不知道到底是什么错误,我写的代码和你的一样。但对我来说效果不错。如果你想你可以使用下面的代码段。
试试看,让我知道。如果你有任何问题。