無法連接到自定義 Akka.NET 傳輸

Question

我正在嘗試實現自定義 Akka.NET Transport 。 目前我有以下內容：

客戶端程序（基於https://getakka.net/articles/remoting/messaging.html ）：

using Akka.Actor;
using Akka.Configuration;
using AkkaTest.Messages;

namespace AkkaTest;

static class Program
{
    static void Main()
    {
        var config = ConfigurationFactory.ParseString(@"
akka {  
    actor {
        provider = remote
    }
    remote {
        enabled-transports = [""akka.remote.myproto""]
        myproto {
            transport-class = ""AkkaTest.Messages.MyTransport, AkkaTest.Messages""
            applied-adapters = []
            transport-protocol = myproto
            port = 0 # bound to a dynamic port assigned by the OS
            hostname = localhost
        }
    }
}");

        var system = ActorSystem.Create("MyActorSystem", config);
        var myActor = system.ActorOf<SendActor>();
        myActor.Tell(new StartRemoting());
        while (true)
        {
            // null task
        }
    }
}

// Initiates remote contact 
public class SendActor : ReceiveActor
{
    public SendActor()
    {
        Receive<StartRemoting>(s => {
            Context.ActorSelection("akka.myproto://RemoteSys@localhost:8081/user/Echo")
            .Tell(new Msg("hi!"));
        });
        Receive<Msg>(msg => {
            Console.WriteLine("Received {0} from {1}", msg.Content, Sender);
        });
    }
}

服務器：

using Akka.Actor;
using Akka.Configuration;
using AkkaTest.Messages;

namespace AkkaTest.Server;

static class Program
{
    static void Main()
    {
        var config = ConfigurationFactory.ParseString(@"
akka {  
    actor {
        provider = remote
    }
    remote {
        enabled-transports = [""akka.remote.myproto""]
        myproto {
            transport-class = ""AkkaTest.Messages.MyTransport, AkkaTest.Messages""
            applied-adapters = []
            transport-protocol = myproto
            port = 8081 #bound to a specific port
            hostname = localhost
        }
    }
}");

        var system = ActorSystem.Create("RemoteSys", config);
        system.ActorOf<EchoActor>("Echo");
        while (true)
        {
            // null task
        }
    }
}

// Runs in a separate process from SendActor
public class EchoActor : ReceiveActor
{
    public EchoActor()
    {
        Receive<Msg>(msg => {
            // echo message back to sender
            Sender.Tell(msg);
        });
    }
}

留言：

namespace AkkaTest.Messages;

// Written into a shared library
public class Msg
{
    public Msg(string content)
    {
        this.Content = content;
    }

    public string Content { get; set; }
}

public class StartRemoting { }

存根關聯事件偵聽器：

namespace AkkaTest.Messages
{
    using Akka.Remote.Transport;

    public class MyAel : IAssociationEventListener
    {
        public void Notify(IAssociationEvent ev)
        {
            throw new NotImplementedException();
        }
    }
}

最后，被截斷的傳輸：

namespace AkkaTest.Messages
{
    using Akka.Actor;
    using Akka.Configuration;
    using Akka.Remote.Transport;
    using System;
    using System.Threading.Tasks;

    public class MyTransport : Transport
    {
        public MyTransport(ActorSystem system, Config config)
        {
            this.System = system;
            this.Config = config;
        }

        public override Task<AssociationHandle> Associate(Address remoteAddress)
        {
            throw new NotImplementedException();
        }

        public override bool IsResponsibleFor(Address remote)
        {
            return remote.Protocol.ToUpper() == this.Config.GetString("transport-protocol").ToUpper();
        }

        public override Task<(Address, TaskCompletionSource<IAssociationEventListener>)> Listen()
        {
            var tcs = new TaskCompletionSource<IAssociationEventListener>();
            tcs.TrySetResult(new MyAel());
            var protocol = this.Config.GetString("transport-protocol");
            var host = this.Config.GetString("hostname");
            var port = this.Config.GetInt("port");
            if (port == 0)
            {
                port = 62978;
            }
            return Task.FromResult((
                new Address(
                    protocol,
                    this.System.Name,
                    host,
                    port),
                tcs));
        }

        public override Task<bool> Shutdown()
        {
            throw new NotImplementedException();
        }
    }
}

以前，我嘗試過使用 TCP 而不是我的自定義傳輸的非常相似的客戶端/服務器設置。 這是服務器 output：

[INFO][9/27/2022 2:29:15 PM][Thread 0001][remoting (akka://RemoteSys)] Starting remoting
[INFO][9/27/2022 2:29:15 PM][Thread 0001][remoting (akka://RemoteSys)] Remoting started; listening on addresses : [akka.tcp://RemoteSys@localhost:8081]
[INFO][9/27/2022 2:29:15 PM][Thread 0001][remoting (akka://RemoteSys)] Remoting now listens on addresses: [akka.tcp://RemoteSys@localhost:8081]

和客戶：

[INFO][9/27/2022 2:29:29 PM][Thread 0001][remoting (akka://MyActorSystem)] Starting remoting
[INFO][9/27/2022 2:29:30 PM][Thread 0001][remoting (akka://MyActorSystem)] Remoting started; listening on addresses : [akka.tcp://MyActorSystem@localhost:62978]
[INFO][9/27/2022 2:29:30 PM][Thread 0001][remoting (akka://MyActorSystem)] Remoting now listens on addresses: [akka.tcp://MyActorSystem@localhost:62978]
Received hi! from [akka.tcp://RemoteSys@localhost:8081/user/Echo#2122916400]

所以這是我的預期行為。 當我使用自定義傳輸啟動服務器項目時，我得到以下控制台 output：

[INFO][9/27/2022 3:49:50 PM][Thread 0001][remoting (akka://RemoteSys)] Starting remoting
[INFO][9/27/2022 3:49:50 PM][Thread 0001][remoting (akka://RemoteSys)] Remoting started; listening on addresses : [akka.myproto://RemoteSys@localhost:8081]
[INFO][9/27/2022 3:49:50 PM][Thread 0001][remoting (akka://RemoteSys)] Remoting now listens on addresses: [akka.myproto://RemoteSys@localhost:8081]

這是我所期望的。 與我在使用 TCP 嘗試相同設置時得到的 output 非常相似。 但是，當我嘗試啟動客戶端時，出現以下錯誤：

[INFO][9/27/2022 3:50:48 PM][Thread 0001][remoting (akka://MyActorSystem)] Starting remoting
[INFO][9/27/2022 3:50:48 PM][Thread 0001][remoting (akka://MyActorSystem)] Remoting started; listening on addresses : [akka.myproto://MyActorSystem@localhost:62978]
[INFO][9/27/2022 3:50:48 PM][Thread 0001][remoting (akka://MyActorSystem)] Remoting now listens on addresses: [akka.myproto://MyActorSystem@localhost:62978]
[ERROR][9/27/2022 3:50:49 PM][Thread 0009][akka://MyActorSystem/user/$a] No transport is loaded for protocol: [akka.myproto], available protocols: [akka.]
Cause: Akka.Remote.RemoteTransportException: No transport is loaded for protocol: [akka.myproto], available protocols: [akka.]
   at Akka.Remote.Remoting.LocalAddressForRemote(IDictionary`2 transportMapping, Address remote)
   at Akka.Remote.RemoteActorRefProvider.RootGuardianAt(Address address)
   at Akka.Actor.ActorRefFactoryShared.ActorSelection(String path, ActorSystem system, IActorRef lookupRoot)
   at AkkaTest.SendActor.<>c.<.ctor>b__0_0(StartRemoting s) in ...\AkkaTest\AkkaTest\Program.cs:line 44
   at lambda_method7(Closure , Object , Action`1 , Action`1 )
   at Akka.Actor.ReceiveActor.OnReceive(Object message)
   at Akka.Actor.UntypedActor.Receive(Object message)
   at Akka.Actor.ActorBase.AroundReceive(Receive receive, Object message)
   at Akka.Actor.ActorCell.ReceiveMessage(Object message)
   at Akka.Actor.ActorCell.Invoke(Envelope envelope)

無論我是否啟動了服務器，我都會遇到同樣的問題，所以它幾乎就好像它甚至沒有嘗試建立關聯一樣。 我懷疑問題可能是我現在有太多的存根（我特別想知道問題是否與tcs.TrySetResult(new MyAel());線有關），但我沒有很多到 go 上要填寫什么； 文檔有點稀疏。 據我所知，沒有任何NotImplementedExceptions被命中，也沒有任何先前的斷點。 那么我在這個階段缺少什么？

Answer 1

找到（當前）問題。 檢查DotnettyTransport的元數據，我注意到它覆蓋了虛擬SchemeIdentifier 。 我在我的ctor中設置了SchemeIdentifier ：

public MyTransport(ActorSystem system, Config config)
{
    this.System = system;
    this.Config = config;
    this.SchemeIdentifier = this.Config.GetString("transport-protocol");
}

在我這樣做之后，我的IsResponsibleFor實現被調用了。 這導致了我的下一個問題，傳入的remote.Protocol屬性沒有像我預期的那樣返回myproto ，而是返回akka.myproto 。 很容易修復：

public override bool IsResponsibleFor(Address remote)
{
    return remote.Protocol.ToUpper() == $"AKKA.{this.SchemeIdentifier.ToUpper()}";
}

以后可能會整理一下。 現在它正在工作，我的Associate覆蓋被調用，當然會拋出它的NotImplemented [yet] Exception 。