我正在尝试创建一个简单的生产者,该生产者使用配置提供的一些分区来创建主题。
根据Alpakka Producer Setting Doc,可以在org.apache.kafka.clients.producer.ProducerConfig
部分中设置kafka-clients
中的任何属性。并且,Producer API Doc中有一个num.partitions
属性。
因此,我将该属性添加到了application.conf
文件中,如下所示:
topic = "topic"
topic = ${?TOPIC}
# Properties for akka.kafka.ProducerSettings can be
# defined in this section or a configuration section with
# the same layout.
akka.kafka.producer {
# Tuning parameter of how many sends that can run in parallel.
parallelism = 100
parallelism = ${?PARALLELISM}
# Duration to wait for `KafkaConsumer.close` to finish.
close-timeout = 20s
# Fully qualified config path which holds the dispatcher configuration
# to be used by the producer stages. Some blocking may occur.
# When this value is empty, the dispatcher configured for the stream
# will be used.
use-dispatcher = "akka.kafka.default-dispatcher"
# The time interval to commit a transaction when using the `Transactional.sink` or `Transactional.flow`
eos-commit-interval = 100ms
# Properties defined by org.apache.kafka.clients.producer.ProducerConfig
# can be defined in this configuration section.
kafka-clients {
bootstrap.servers = "my-kafka:9092"
bootstrap.servers = ${?BOOTSTRAPSERVERS}
num.partitions = "3"
num.partitions = ${?NUM_PARTITIONS}
}
}
下面还提供了生产者应用程序代码:
object Main extends App {
val config = ConfigFactory.load()
implicit val system: ActorSystem = ActorSystem("producer")
implicit val materializer: Materializer = ActorMaterializer()
val producerConfigs = config.getConfig("akka.kafka.producer")
val producerSettings = ProducerSettings(producerConfigs, new StringSerializer, new StringSerializer)
val topic = config.getString("topic")
val done: Future[Done] =
Source(1 to 100000)
.map(_.toString)
.map(value => new ProducerRecord[String, String](topic, value))
.runWith(Producer.plainSink(producerSettings))
implicit val ec: ExecutionContextExecutor = system.dispatcher
done onComplete {
case Success(_) => println("Done"); system.terminate()
case Failure(err) => println(err.toString); system.terminate()
}
}
但是,这不起作用。 Producer用一个分区而不是我通过配置设置的3个分区创建一个主题:
num.partitions = "3"
最后,Kafkacat的输出如下:
~$ kafkacat -b my-kafka:9092 -L
Metadata for all topics (from broker -1: my-kafka:9092/bootstrap):
3 brokers:
broker 2 at my-kafka-2.my-kafka-headless.default:9092
broker 1 at my-kafka-1.my-kafka-headless.default:9092
broker 0 at my-kafka-0.my-kafka-headless.default:9092
1 topics:
topic "topic" with 1 partitions:
partition 0, leader 2, replicas: 2, isrs: 2
怎么了?是否可以使用Alpakka在kafka-clients
部分的Kafka Producer API中设置属性?
答案 0 :(得分:2)
#org.apache.kafka.clients.producer.ProducerConfig定义的属性
#可以在此配置部分中定义。
就像这样说,ProducerConfig
用于生产者设置,而不是代理设置,num.partitions
是(我认为您迷失了该属性在Apache Kafka文档上显示的哪个表中。 。滚动到其顶部以查看适当的标题)。
无法通过生产者设置主题的分区...您将需要使用AdminClient
类来创建主题,并且分区数是那里的一个参数,而不是配置属性。
示例代码
val props = new Properties()
props.setProperty(AdminClientConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092")
val adminClient = AdminClient.create(props)
val numPartitions = 3
val replicationFactor = 3.toShort
val newTopic = new NewTopic("new-topic-name", numPartitions, replicationFactor)
val configs = Map(TopicConfig.COMPRESSION_TYPE_CONFIG -> "gzip")
// settings some configs
newTopic.configs(configs.asJava)
adminClient.createTopics(List(newTopic).asJavaCollection)
然后您可以启动制作人
答案 1 :(得分:1)
似乎该主题是通过Default创建的,这是Kafka的默认行为。如果是这种情况,则需要在代理的server.properties文件中定义默认的分区数。
# The default number of log partitions per topic. More partitions allow greater
# parallelism for consumption, but this will also result in more files across
# the brokers.
num.partitions=3