Akka Remoting：启用序列化后的死信

Question

我正在研究一个 Akka-Remoting 示例。在将序列化支持配置到 application.conf 文件之前，它运行良好。但是，启用序列化后，消息无法正确传递。

在接收和发送消息时，我可以在远程和客户端应用程序上看到 DeadLetter 的日志。我认为消息正在交换，但没有传递给正确的参与者。

这是在akka-mircokernel中运行的远程计算器的conf文件。

remoteCalculator {
  akka {
    actor {
      #serialize-messages = on

  #No need to define serializers: java and protobuf are supported by Akka.
  serializers {
    java = "akka.serialization.JavaSerializer"
    #akka-containers = "akka.remote.serialization.MessageContainerSerializer"
    proto = "akka.remote.serialization.ProtobufSerializer"
    #daemon-create = "akka.remote.serialization.DaemonMsgCreateSerializer"
 }

serialization-bindings {
  #"akka.actor.ActorSelectionMessage" = akka-containers
  #"com.google.protobuf.GeneratedMessage" = proto
  #"akka.remote.DaemonMsgCreate" = daemon-create
  "java.lang.Integer"       = proto
  "scala.Int"               = proto
  "akka.example.MathOp" = proto
  #"akka.example.Add"       = proto
  #"akka.example.Subtract" = proto
  #"akka.example.Multiply" = proto
  #"akka.example.Divide"    = proto
  "akka.example.MathResult"         = proto
  #"akka.example.AddResult"             = proto
  #"akka.example.SubtractResult"        = proto
  #"akka.example.MultiplicationResult" = proto
  #"akka.example.DivisionResult"        = proto 
}
provider = "akka.remote.RemoteActorRefProvider"
}
remote {
  log-received-messages = on
  log-sent-messages = on
  log-remote-lifecycle-events = on
  enabled-transports = ["akka.remote.netty.tcp"]
  netty.tcp {
    hostname = "IGLR000PBG3K8Y-ubuntu"
    port = 2555
    log-received-messages = on
    log-sent-messages = on
    log-remote-lifecycle-events = on
  }
 }
}
}

以及计算器客户端应用程序的 conf 文件

LocalSys {
  akka {
    actor {
      #serialize-messages = on

  #No need to define serializers: java and protobuf are supported by Akka.
  serializers {
    java = "akka.serialization.JavaSerializer"
    #akka-containers = "akka.remote.serialization.MessageContainerSerializer"
    proto = "akka.remote.serialization.ProtobufSerializer"
    #daemon-create = "akka.remote.serialization.DaemonMsgCreateSerializer"
 }

serialization-bindings {
  #"akka.actor.ActorSelectionMessage" = akka-containers
  #"com.google.protobuf.GeneratedMessage" = proto
  #"akka.remote.DaemonMsgCreate" = daemon-create
  "java.lang.Integer"       = proto
  "scala.Int"               = proto
  "akka.example.MathOp" = proto
  #"akka.example.Add"       = proto
  #"akka.example.Subtract" = proto
  #"akka.example.Multiply" = proto
  #"akka.example.Divide"    = proto
  "akka.example.MathResult"         = proto
  #"akka.example.AddResult"             = proto
  #"akka.example.SubtractResult"        = proto
  #"akka.example.MultiplicationResult" = proto
  #"akka.example.DivisionResult"        = proto 
}
provider = "akka.remote.RemoteActorRefProvider"
}
remote {
  log-received-messages = on
  log-sent-messages = on
  log-remote-lifecycle-events = on
  enabled-transports = ["akka.remote.netty.tcp"]
  netty.tcp {
    hostname = "IGLR000PBG3K8Y-ubuntu"
    port = 2556
    log-received-messages = on
    log-sent-messages = on
    log-remote-lifecycle-events = on
  }
 }
}

}

这是我在远程计算器控制台上看到的内容

[INFO] [11/27/2013 18:40:00.425] [CalculatorApplication-akka.actor.default-dispatcher-6] [akka://CalculatorApplication/system/transports/akkaprotocolmanager.tcp0/akkaProtocol-tcp%3A%2F%2FCalculatorApplication%4010.147.137.227%3A60905-1] Message [akka.remote.transport.ActorTransportAdapter$DisassociateUnderlying] from Actor[akka://CalculatorApplication/deadLetters] to Actor[akka://CalculatorApplication/system/transports/akkaprotocolmanager.tcp0/akkaProtocol-tcp%3A%2F%2FCalculatorApplication%4010.147.137.227%3A60905-1#-1343833615] was not delivered. [1] dead letters encountered. This logging can be turned off or adjusted with configuration settings 'akka.log-dead-letters' and 'akka.log-dead-letters-during-shutdown'.
[INFO] [11/27/2013 18:40:00.429] [CalculatorApplication-akka.actor.default-dispatcher-5] [akka://CalculatorApplication/system/transports/akkaprotocolmanager.tcp0/akkaProtocol-tcp%3A%2F%2FCalculatorApplication%4010.147.137.227%3A60905-1] Message [akka.remote.transport.AssociationHandle$Disassociated] from Actor[akka://CalculatorApplication/deadLetters] to Actor[akka://CalculatorApplication/system/transports/akkaprotocolmanager.tcp0/akkaProtocol-tcp%3A%2F%2FCalculatorApplication%4010.147.137.227%3A60905-1#-1343833615] was not delivered. [2] dead letters encountered. This logging can be turned off or adjusted with configuration settings 'akka.log-dead-letters' and 'akka.log-dead-letters-during-shutdown'.

在计算器客户端控制台上

[INFO] [11/27/2013 18:40:00.343] [clientkernel-akka.actor.default-dispatcher-2] [akka://clientkernel/system/endpointManager/reliableEndpointWriter-akka.tcp%3A%2F%2FCalculatorApplication%40IGLR000PBG3K8Y-ubuntu.ampf.com%3A2555-0/endpointWriter/endpointReader-akka.tcp%3A%2F%2FCalculatorApplication%40IGLR000PBG3K8Y-ubuntu%3A2555-0] Message [akka.remote.transport.AssociationHandle$Disassociated] from Actor[akka://clientkernel/deadLetters] to Actor[akka://clientkernel/system/endpointManager/reliableEndpointWriter-akka.tcp%3A%2F%2FCalculatorApplication%40IGLR000PBG3K8Y-ubuntu.ampf.com%3A2555-0/endpointWriter/endpointReader-akka.tcp%3A%2F%2FCalculatorApplication%40IGLR000PBG3K8Y-ubuntu%3A2555-0#-773728878] was not delivered. [1] dead letters encountered. This logging can be turned off or adjusted with configuration settings 'akka.log-dead-letters' and 'akka.log-dead-letters-during-shutdown'.
[INFO] [11/27/2013 18:40:00.361] [clientkernel-akka.actor.default-dispatcher-3] [akka://clientkernel/system/transports/akkaprotocolmanager.tcp0/akkaProtocol-tcp%3A%2F%2FCalculatorApplication%40IGLR000PBG3K8Y-ubuntu%3A2555-1] Message [akka.remote.transport.AssociationHandle$Disassociated] from Actor[akka://clientkernel/deadLetters] to Actor[akka://clientkernel/system/transports/akkaprotocolmanager.tcp0/akkaProtocol-tcp%3A%2F%2FCalculatorApplication%40IGLR000PBG3K8Y-ubuntu%3A2555-1#-249262169] was not delivered. [2] dead letters encountered. This logging can be turned off or adjusted with configuration settings 'akka.log-dead-letters' and 'akka.log-dead-letters-during-shutdown'.

在启用序列化之前，一切正常。我无法弄清楚我缺少哪些配置选项或做错了什么。任何帮助表示赞赏。

编辑：我是否需要扩展我的 pojo 中的任何类才能使序列化正常工作？

Answer 1

如果更改序列化配置导致消息丢失，那么显然序列化必须失败（我不会称其为“启用”，因为序列化必须始终发生）。您配置为使用 protobuf 的类不适合该序列化程序，它只知道如何处理com.google.protobuf.Message。您必须定义一个 protobuf 协议定义，使用 protoc 对其进行编译，然后将生成的类用作消息，或者编写您自己的序列化程序，将您的消息类（如 MathOp）转换为它们的 protobuf 等效项。

Protobuf 不是自动的；您还可以查看 kryo，其中有一个外部维护的 akka 模块。