我有一个kafka消费者,看起来如下:
import akka.actor.ActorSystem
import akka.kafka.scaladsl.Consumer
import akka.kafka.{ConsumerSettings, Subscriptions}
import akka.stream.ActorMaterializer
import akka.stream.scaladsl.Sink
import org.apache.kafka.clients.consumer.ConsumerConfig
import org.apache.kafka.common.serialization.StringDeserializer
import scala.util.{Failure, Success}
object App {
def main(args: Array[String]): Unit = {
implicit val system = ActorSystem("SAP-SENDER")
implicit val executor = system.dispatcher
implicit val materilizer = ActorMaterializer()
val config = system.settings.config.getConfig("akka.kafka.consumer")
val consumerSettings: ConsumerSettings[String, String] =
ConsumerSettings(config, new StringDeserializer, new StringDeserializer)
.withBootstrapServers("localhost:9003")
.withGroupId("SAPSENDER")
.withProperty(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "latest")
Consumer
.plainSource(
consumerSettings,
Subscriptions.topics("TEST-TOPIC")
)
.runWith(Sink.foreach(println))
.onComplete{
case Success(_) => println("Goood")
case Failure(ex) =>
println(s"I am failed ==============> ${ex.getMessage}")
system.terminate()
}
}
}
kafka服务器不活动,我想终止消费者。它总是尝试连接并显示以下消息:
19:03:47.342 [SAP-SENDER-akka.kafka.default-dispatcher-15] DEBUG org.apache.kafka.clients.consumer.KafkaConsumer - [Consumer clientId=consumer-1, groupId=SAPSENDER] Pausing partitions []
19:03:47.342 [SAP-SENDER-akka.kafka.default-dispatcher-15] DEBUG org.apache.kafka.clients.consumer.internals.AbstractCoordinator - [Consumer clientId=consumer-1, groupId=SAPSENDER] No broker available to send FindCoordinator request
19:03:47.342 [SAP-SENDER-akka.kafka.default-dispatcher-15] DEBUG org.apache.kafka.clients.NetworkClient - [Consumer clientId=consumer-1, groupId=SAPSENDER] Give up sending metadata request since no node is available
19:03:47.342 [SAP-SENDER-akka.kafka.default-dispatcher-15] DEBUG org.apache.kafka.clients.consumer.internals.AbstractCoordinator - [Consumer clientId=consumer-1, groupId=SAPSENDER] Coordinator discovery failed, refreshing metadata
19:03:47.342 [SAP-SENDER-akka.kafka.default-dispatcher-15] DEBUG org.apache.kafka.clients.NetworkClient - [Consumer clientId=consumer-1, groupId=SAPSENDER] Give up sending metadata request since no node is available
19:03:47.412 [SAP-SENDER-akka.kafka.default-dispatcher-17] DEBUG org.apache.kafka.clients.consumer.KafkaConsumer - [Consumer clientId=consumer-1, groupId=SAPSENDER] Pausing partitions []
19:03:47.412 [SAP-SENDER-akka.kafka.default-dispatcher-17] DEBUG org.apache.kafka.clients.consumer.internals.AbstractCoordinator - [Consumer clientId=consumer-1, groupId=SAPSENDER] No broker available to send FindCoordinator request
19:03:47.412 [SAP-SENDER-akka.kafka.default-dispatcher-17] DEBUG org.apache.kafka.clients.NetworkClient - [Consumer clientId=consumer-1, groupId=SAPSENDER] Give up sending metadata request since no node is available
19:03:47.412 [SAP-SENDER-akka.kafka.default-dispatcher-17] DEBUG org.apache.kafka.clients.consumer.internals.AbstractCoordinator - [Consumer clientId=consumer-1, groupId=SAPSENDER] Coordinator discovery failed, refreshing metadata
19:03:47.412 [SAP-SENDER-akka.kafka.default-dispatcher-17] DEBUG org.apache.kafka.clients.NetworkClient - [Consumer clientId=consumer-1, groupId=SAPSENDER] Give up sending metadata request since no node is available
19:03:47.478 [SAP-SENDER-akka.kafka.default-dispatcher-20] DEBUG org.apache.kafka.clients.consumer.KafkaConsumer - [Consumer clientId=consumer-1, groupId=SAPSENDER] Pausing partitions []
它还说:
java.net.ConnectException: Connection refused
at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:717)
at org.apache.kafka.common.network.PlaintextTransportLayer.finishConnect(PlaintextTransportLayer.java:50)
at org.apache.kafka.common.network.KafkaChannel.finishConnect(KafkaChannel.java:173)
at org.apache.kafka.common.network.Selector.pollSelectionKeys(Selector.java:515)
at org.apache.kafka.common.network.Selector.poll(Selector.java:467)
at org.apache.kafka.clients.NetworkClient.poll(NetworkClient.java:535)
at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.poll(ConsumerNetworkClient.java:265)
at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.poll(ConsumerNetworkClient.java:236)
at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.poll(ConsumerNetworkClient.java:215)
at org.apache.kafka.clients.consumer.internals.AbstractCoordinator.ensureCoordinatorReady(AbstractCoordinator.java:231)
at org.apache.kafka.clients.consumer.internals.ConsumerCoordinator.poll(ConsumerCoordinator.java:316)
at org.apache.kafka.clients.consumer.KafkaConsumer.updateAssignmentMetadataIfNeeded(KafkaConsumer.java:1214)
at org.apache.kafka.clients.consumer.KafkaConsumer.poll(KafkaConsumer.java:1179)
at org.apache.kafka.clients.consumer.KafkaConsumer.poll(KafkaConsumer.java:1164)
at akka.kafka.internal.KafkaConsumerActor.poll(KafkaConsumerActor.scala:380)
at akka.kafka.internal.KafkaConsumerActor.akka$kafka$internal$KafkaConsumerActor$$receivePoll(KafkaConsumerActor.scala:360)
at akka.kafka.internal.KafkaConsumerActor$$anonfun$receive$1.applyOrElse(KafkaConsumerActor.scala:221)
at akka.actor.Actor.aroundReceive(Actor.scala:539)
at akka.actor.Actor.aroundReceive$(Actor.scala:537)
at akka.kafka.internal.KafkaConsumerActor.akka$actor$Timers$$super$aroundReceive(KafkaConsumerActor.scala:142)
at akka.actor.Timers.aroundReceive(Timers.scala:51)
at akka.actor.Timers.aroundReceive$(Timers.scala:40)
at akka.kafka.internal.KafkaConsumerActor.aroundReceive(KafkaConsumerActor.scala:142)
at akka.actor.ActorCell.receiveMessage(ActorCell.scala:610)
at akka.actor.ActorCell.invoke(ActorCell.scala:579)
at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:268)
at akka.dispatch.Mailbox.run(Mailbox.scala:229)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
如何赶上流中的ConnectException
并阻止消费者尝试连接kafka。
使用Kafka Client 2.0+ Alpakka Kafka无法注意到给定地址上没有可用的Kafka经纪人。
看看这个PR和升级到kafka客户端2.0的工作,我猜想很多重试责任已经委托给了kafka客户端。例如,我尝试传递这些属性
val consumerSettings: ConsumerSettings[String, String] =
ConsumerSettings(config, new StringDeserializer, new StringDeserializer)
.withProperties(
"reconnect.backoff.ms" -> "10000",
"reconnect.backoff.max.ms" -> "20000"
)
.withBootstrapServers("localhost:9099")
.withGroupId("SAPSENDER")
.withProperty(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "latest")
并且例外在10秒后第二次出现。我找到了这些属性here
考虑到这一点,我认为kafka客户端的新改编可能缺少一个功能,因为KafkaConsumerActor没有将异常暴露给流,我尝试使用你的repo进行各种组合,但我仍然得到连续的调试消息流。
我希望这能为正确的方向提供一些提示,如果你解决了,请告诉我们。
您应监视流并在出现错误时重新启动它。例如,您可以在actor内部运行流,并处理与actor监督的错误连接。
连接错误可能会在几秒钟内持续(可能是网络不堪重负),因此您应该使用退避策略来避免重试风暴。
Akka流已经为您提供了一种使用RestartSource
为流做这个的简单方法。见Error Handling
val control = new AtomicReference[Consumer.Control](Consumer.NoopControl)
val result = RestartSource
.onFailuresWithBackoff(
minBackoff = 3.seconds,
maxBackoff = 30.seconds,
randomFactor = 0.2
) { () =>
Consumer
.plainSource(consumerSettings, Subscriptions.topics(topic))
// this is a hack to get access to the Consumer.Control
// instances of the latest Kafka Consumer source
.mapMaterializedValue(c => control.set(c))
.via(businessFlow)
}
.runWith(Sink.seq)
control.get().shutdown()
此解决方案仅在启动流并且代理已关闭时才起作用,因为当您尝试创建它时,使用者会抛出异常。但是,如果您成功创建了消费者,之后整个kafka集群崩溃,内部KafkaConsumer将使用提到的reconnect.backoff.ms
和reconnect.backoff.max.ms
配置重新连接,您的流将不会失败。
如果您想限制退休人数,您应该执行以下操作
val result: Future[Done] = RestartSource
.onFailuresWithBackoff(
minBackoff = 3.seconds,
maxBackoff = 30.seconds,
randomFactor = 0.2
) { () => // your consumer
}.
.take(3) // retries limit
.runWith(Sink.ignore)
result.onComplete {
case _ => println("Max retries reached")
}