Scala Pubsub使用主题组和Akka集群_Scala_Akka_Publish Subscribe_Akka Cluster

Scala Pubsub使用主题组和Akka集群

scala akka

Scala Pubsub使用主题组和Akka集群,scala,akka,publish-subscribe,akka-cluster,Scala,Akka,Publish Subscribe,Akka Cluster,我正在尝试用Akka集群创建一个pubsub风格的应用程序。我正在阅读关于pubsub的文章，现在尝试运行他们的示例我的基本工作流程如下：运行订阅者（成为主/领导者的订阅者）。运行发布者（发布者将向主题发送字符串。所有订阅者都将收到此消息）这是我的密码： Subscriber.scala Publisher.scala application.conf 我发现，当我运行发布者的main时，它将在尝试发布到“内容”主题时挂起，而订阅者没有收到消息发布者的日志包含以下内容： [INFO][

我正在尝试用Akka集群创建一个pubsub风格的应用程序。我正在阅读关于pubsub的文章，现在尝试运行他们的示例

我的基本工作流程如下：

运行订阅者（成为主/领导者的订阅者）。运行发布者（发布者将向主题发送字符串。所有订阅者都将收到此消息）

这是我的密码：

Subscriber.scala

Publisher.scala

application.conf

我发现，当我运行发布者的main时，它将在尝试发布到“内容”主题时挂起，而订阅者没有收到消息

发布者的日志包含以下内容：

[INFO][12/09/2016 15:14:35.513][ClusterSystem akka.actor.default-dispatcher-18][akka://ClusterSystem/system/distributedPubSubMediator]来自Actor的消息[java.lang.String][akka://ClusterSystem/user/Publisher#-1478463431]给演员[akka://ClusterSystem/system/distributedPubSubMediator#-1539813703]未交付。[1] 遇到死信。可以使用配置设置“akka.log死信”和“akka.log关机时死信”关闭或调整此日志记录。

我一直在仔细研究文档，但似乎提到主题概念更多的是事后思考

为什么我的订阅者没有收到这条消息？

发布者和订阅者实际上都很好。问题来自这样一个事实，即您从分布式发布子示例开始。当然，作为前提条件，您需要设置集群，以便通过集群分发消息

Main.scala

：

import akka.actor.ActorSystem
import akka.actor.Props
import akka.cluster.Cluster
import com.example.Publisher
import com.example.Subscriber

object Main {
  def main(args: Array[String]): Unit = {
    val systemName = "PubSub"
    val system1 = ActorSystem(systemName)
    val joinAddress = Cluster(system1).selfAddress
    Cluster(system1).join(joinAddress)
    val publisher = system1.actorOf(Props[Publisher], "publisher")

    Thread.sleep(5000)
    val system2 = ActorSystem(systemName)
    Cluster(system2).join(joinAddress)
    system2.actorOf(Props[Subscriber], "subscriber")

    Thread.sleep(5000)
    publisher ! "something"
  }
}

如果现在运行

Main.scala

，您将看到以下内容：

正在创建system1并加入集群（隐式创建）
正在创建system2，它将加入群集
消息被发送到发布者，发布者将消息转发给中介，中介将消息分发到集群中
订阅者获得消息

编辑：我简化了您的

应用程序.conf

如下：

akka {
  loglevel = "INFO"
  actor {
    provider = "akka.cluster.ClusterActorRefProvider"
  }
  remote {
    log-remote-lifecycle-events = off
    netty.tcp {
      hostname = "127.0.0.1"
      port = 0
    }
  }

  log-dead-letters = 0
  log-dead-letters-during-shutdown = off
}

注意

netty.tcp.port=0

——这将保证您获得随机分配的端口，并且集群成员不会发生端口冲突。您可以在我的输出中看到端口49759和49772

输出：

Running Main 
[INFO] [12/10/2016 12:44:09.175] [main] [akka.remote.Remoting] Starting remoting
[INFO] [12/10/2016 12:44:09.439] [main] [akka.remote.Remoting] Remoting started; listening on addresses :[akka.tcp://PubSub@127.0.0.1:49759]
[INFO] [12/10/2016 12:44:09.451] [main] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49759] - Starting up...
[INFO] [12/10/2016 12:44:09.537] [main] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49759] - Started up successfully
[INFO] [12/10/2016 12:44:09.537] [main] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49759] - Registered cluster JMX MBean [akka:type=Cluster]
[INFO] [12/10/2016 12:44:09.546] [PubSub-akka.actor.default-dispatcher-2] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49759] - Metrics will be retreived from MBeans, and may be incorrect on some platforms. To increase metric accuracy add the 'sigar.jar' to the classpath and the appropriate platform-specific native libary to 'java.library.path'. Reason: java.lang.ClassNotFoundException: org.hyperic.sigar.Sigar
[INFO] [12/10/2016 12:44:09.549] [PubSub-akka.actor.default-dispatcher-2] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49759] - Metrics collection has started successfully
[INFO] [12/10/2016 12:44:09.573] [PubSub-akka.actor.default-dispatcher-3] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49759] - No seed-nodes configured, manual cluster join required
[INFO] [12/10/2016 12:44:09.594] [PubSub-akka.actor.default-dispatcher-3] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49759] - Node [akka.tcp://PubSub@127.0.0.1:49759] is JOINING, roles []
[INFO] [12/10/2016 12:44:09.606] [PubSub-akka.actor.default-dispatcher-3] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49759] - Leader is moving node [akka.tcp://PubSub@127.0.0.1:49759] to [Up]
[INFO] [12/10/2016 12:44:14.598] [main] [akka.remote.Remoting] Starting remoting
[INFO] [12/10/2016 12:44:14.616] [main] [akka.remote.Remoting] Remoting started; listening on addresses :[akka.tcp://PubSub@127.0.0.1:49772]
[INFO] [12/10/2016 12:44:14.617] [main] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49772] - Starting up...
[INFO] [12/10/2016 12:44:14.626] [main] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49772] - Started up successfully
[INFO] [12/10/2016 12:44:14.627] [PubSub-akka.actor.default-dispatcher-19] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49772] - Metrics will be retreived from MBeans, and may be incorrect on some platforms. To increase metric accuracy add the 'sigar.jar' to the classpath and the appropriate platform-specific native libary to 'java.library.path'. Reason: java.lang.ClassNotFoundException: org.hyperic.sigar.Sigar
[INFO] [12/10/2016 12:44:14.627] [PubSub-akka.actor.default-dispatcher-19] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49772] - Metrics collection has started successfully
[INFO] [12/10/2016 12:44:14.633] [PubSub-akka.actor.default-dispatcher-3] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49772] - No seed-nodes configured, manual cluster join required
[INFO] [12/10/2016 12:44:14.653] [PubSub-akka.actor.default-dispatcher-16] [akka.tcp://PubSub@127.0.0.1:49772/user/subscriber] subscribing
[INFO] [12/10/2016 12:44:14.844] [PubSub-akka.actor.default-dispatcher-16] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49759] - Node [akka.tcp://PubSub@127.0.0.1:49772] is JOINING, roles []
[INFO] [12/10/2016 12:44:14.920] [PubSub-akka.actor.default-dispatcher-21] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49772] - Welcome from [akka.tcp://PubSub@127.0.0.1:49759]
[INFO] [12/10/2016 12:44:15.580] [PubSub-akka.actor.default-dispatcher-17] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49759] - Leader is moving node [akka.tcp://PubSub@127.0.0.1:49772] to [Up]
Received 'something', transformed to 'SOMETHING'.
[INFO] [12/10/2016 12:44:19.673] [PubSub-akka.actor.default-dispatcher-4] [akka.tcp://PubSub@127.0.0.1:49772/user/subscriber] Got SOMETHING

出版商和订阅者都很好。问题来自这样一个事实，即您从分布式发布子示例开始。当然，作为前提条件，您需要设置集群，以便通过集群分发消息

Main.scala

：

import akka.actor.ActorSystem
import akka.actor.Props
import akka.cluster.Cluster
import com.example.Publisher
import com.example.Subscriber

object Main {
  def main(args: Array[String]): Unit = {
    val systemName = "PubSub"
    val system1 = ActorSystem(systemName)
    val joinAddress = Cluster(system1).selfAddress
    Cluster(system1).join(joinAddress)
    val publisher = system1.actorOf(Props[Publisher], "publisher")

    Thread.sleep(5000)
    val system2 = ActorSystem(systemName)
    Cluster(system2).join(joinAddress)
    system2.actorOf(Props[Subscriber], "subscriber")

    Thread.sleep(5000)
    publisher ! "something"
  }
}

如果现在运行

Main.scala

，您将看到以下内容：

正在创建system1并加入集群（隐式创建）
正在创建system2，它将加入群集
消息被发送到发布者，发布者将消息转发给中介，中介将消息分发到集群中
订阅者获得消息

编辑：我简化了您的

应用程序.conf

如下：

akka {
  loglevel = "INFO"
  actor {
    provider = "akka.cluster.ClusterActorRefProvider"
  }
  remote {
    log-remote-lifecycle-events = off
    netty.tcp {
      hostname = "127.0.0.1"
      port = 0
    }
  }

  log-dead-letters = 0
  log-dead-letters-during-shutdown = off
}

注意

netty.tcp.port=0

——这将保证您获得随机分配的端口，并且集群成员不会发生端口冲突。您可以在我的输出中看到端口49759和49772

输出：

Running Main 
[INFO] [12/10/2016 12:44:09.175] [main] [akka.remote.Remoting] Starting remoting
[INFO] [12/10/2016 12:44:09.439] [main] [akka.remote.Remoting] Remoting started; listening on addresses :[akka.tcp://PubSub@127.0.0.1:49759]
[INFO] [12/10/2016 12:44:09.451] [main] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49759] - Starting up...
[INFO] [12/10/2016 12:44:09.537] [main] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49759] - Started up successfully
[INFO] [12/10/2016 12:44:09.537] [main] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49759] - Registered cluster JMX MBean [akka:type=Cluster]
[INFO] [12/10/2016 12:44:09.546] [PubSub-akka.actor.default-dispatcher-2] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49759] - Metrics will be retreived from MBeans, and may be incorrect on some platforms. To increase metric accuracy add the 'sigar.jar' to the classpath and the appropriate platform-specific native libary to 'java.library.path'. Reason: java.lang.ClassNotFoundException: org.hyperic.sigar.Sigar
[INFO] [12/10/2016 12:44:09.549] [PubSub-akka.actor.default-dispatcher-2] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49759] - Metrics collection has started successfully
[INFO] [12/10/2016 12:44:09.573] [PubSub-akka.actor.default-dispatcher-3] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49759] - No seed-nodes configured, manual cluster join required
[INFO] [12/10/2016 12:44:09.594] [PubSub-akka.actor.default-dispatcher-3] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49759] - Node [akka.tcp://PubSub@127.0.0.1:49759] is JOINING, roles []
[INFO] [12/10/2016 12:44:09.606] [PubSub-akka.actor.default-dispatcher-3] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49759] - Leader is moving node [akka.tcp://PubSub@127.0.0.1:49759] to [Up]
[INFO] [12/10/2016 12:44:14.598] [main] [akka.remote.Remoting] Starting remoting
[INFO] [12/10/2016 12:44:14.616] [main] [akka.remote.Remoting] Remoting started; listening on addresses :[akka.tcp://PubSub@127.0.0.1:49772]
[INFO] [12/10/2016 12:44:14.617] [main] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49772] - Starting up...
[INFO] [12/10/2016 12:44:14.626] [main] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49772] - Started up successfully
[INFO] [12/10/2016 12:44:14.627] [PubSub-akka.actor.default-dispatcher-19] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49772] - Metrics will be retreived from MBeans, and may be incorrect on some platforms. To increase metric accuracy add the 'sigar.jar' to the classpath and the appropriate platform-specific native libary to 'java.library.path'. Reason: java.lang.ClassNotFoundException: org.hyperic.sigar.Sigar
[INFO] [12/10/2016 12:44:14.627] [PubSub-akka.actor.default-dispatcher-19] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49772] - Metrics collection has started successfully
[INFO] [12/10/2016 12:44:14.633] [PubSub-akka.actor.default-dispatcher-3] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49772] - No seed-nodes configured, manual cluster join required
[INFO] [12/10/2016 12:44:14.653] [PubSub-akka.actor.default-dispatcher-16] [akka.tcp://PubSub@127.0.0.1:49772/user/subscriber] subscribing
[INFO] [12/10/2016 12:44:14.844] [PubSub-akka.actor.default-dispatcher-16] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49759] - Node [akka.tcp://PubSub@127.0.0.1:49772] is JOINING, roles []
[INFO] [12/10/2016 12:44:14.920] [PubSub-akka.actor.default-dispatcher-21] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49772] - Welcome from [akka.tcp://PubSub@127.0.0.1:49759]
[INFO] [12/10/2016 12:44:15.580] [PubSub-akka.actor.default-dispatcher-17] [akka.cluster.Cluster(akka://PubSub)] Cluster Node [akka.tcp://PubSub@127.0.0.1:49759] - Leader is moving node [akka.tcp://PubSub@127.0.0.1:49772] to [Up]
Received 'something', transformed to 'SOMETHING'.
[INFO] [12/10/2016 12:44:19.673] [PubSub-akka.actor.default-dispatcher-4] [akka.tcp://PubSub@127.0.0.1:49772/user/subscriber] Got SOMETHING

有趣。如果我有任意数量的主题，单个集群是否会相应地路由流量，或者我是否需要

集群对象来访问

主题？一个主题可以有多个订阅者。对于主题，您还可以选择定义主题组。参与者可以订阅具有组id的命名主题。如果使用组id订阅，则发布到主题且

sendOneMessageToEachGroup

标志设置为

true

的每条消息都会传递给每个订阅组中的一个参与者。有趣。如果我有任意数量的主题，单个集群是否会相应地路由流量，或者我是否需要

集群对象来访问

主题？一个主题可以有多个订阅者。对于主题，您还可以选择定义主题组。参与者可以订阅具有组id的命名主题。如果使用组id订阅，则发布到主题且

sendOneMessageToEachGroup

标志设置为

true

的每条消息都会传递给每个订阅组中的一个参与者。