第二条消息在我的 Akka.Net 演员中变为未处理,然后它似乎停止了

Second message becomes Unhandled in my Akka.Net actor and then it seems to halt

免责声明:我是 Akka 的新手 :)

我正在尝试在 Akka 中实现一个路由器,基本上

  1. 收到消息
  2. 在字典中查找处理消息类型的 IActorRef
  3. 如果找不到匹配项,使用 Akka.DI 作为子演员创建一个并添加到字典
  4. 将消息转发给该演员

这很好用 - 第一次,但如果我尝试 Tell() 或 Ask() 路由器两次,第二条消息总是以未处理的形式在流中结束

我已经尝试覆盖子 actor 中的 Unhandled() 并在那里放置一个断点,实际上是在第二条消息中命中。

路由器:

public class CommandRouter : UntypedActor
{
    protected readonly IActorResolver _resolver;
    private static readonly Dictionary<Type, IActorRef> _routees = new Dictionary<Type, IActorRef>();
    private ILoggingAdapter _log = Context.GetLogger(new SerilogLogMessageFormatter());

    public CommandRouter(IActorResolver resolver)
    {
        _resolver = resolver;
    }

    protected override void OnReceive(object message)
    {
        _log.Info("Routing command {cmd}", message);
        var typeKey = message.GetType();

        if (!_routees.ContainsKey(typeKey))
        {
            var props = CreateActorProps(typeKey);

            if (!props.Any())
            {
                Sender?.Tell(Response.WithException(
                    new RoutingException(
                        $"Could not route message to routee. No routees found for message type {typeKey.FullName}")));
                return;
            }

            if (props.Count() > 1)
            {
                Sender?.Tell(Response.WithException(
                    new RoutingException(
                        $"Multiple routees registered for message {typeKey.FullName}, which is not supported by this router. Did you want to publish stuff instead?")));
                return;
            }

            var prop = props.First();
            var routee = Context.ActorOf(prop, prop.Type.Name);
            _routees.Add(typeKey, routee);
        }

        _routees[typeKey].Forward(message);

    }

    private IEnumerable<Props> CreateActorProps(Type messageType)
    {
        return _resolver.TryCreateActorProps(typeof(IHandleCommand<>).MakeGenericType(messageType)).ToList();
    }

    protected override SupervisorStrategy SupervisorStrategy()
    {
        return new OneForOneStrategy(x => Directive.Restart);
    }
}

ActorResolver 方法,它使用来自 Akka.DI.StructureMap:

的 DependencyResolver
public IEnumerable<Props> TryCreateActorProps(Type actorType)
{
    foreach (var type in _container.GetAllInstances(actorType))
    {
        yield return _resolver.Create(type.GetType());
    }
}

真正的童星很直白:

public class ProductSubscriptionHandler : ReceiveActor, IHandleCommand<AddProductSubscription>
{
    public ProductSubscriptionHandler()
    {
        Receive<AddProductSubscription>(Handle);
    }

    protected bool Handle(AddProductSubscription command)
    {
        Sender?.Tell(Response.Empty);
        return true;
    }
}

整个过程在 actor 系统初始化后调用,如下所示:

var router = Sys.ActorOf(resolver.Create<CommandRouter>(), ActorNames.CommandRouter);

router.Ask(new AddProductSubscription());
router.Ask(new AddProductSubscription());

我一直在第二条(或任何后续)消息中收到此错误:"Unhandled message from...":

[INFO][17-07-2017 23:05:39][Thread 0003][[akka://pos-system/user/CommandRouter#676182398]] Routing command Commands.AddProductSubscription
[DEBUG][17-07-2017 23:05:39][Thread 0003][akka://pos-system/user/CommandRouter] now supervising akka://pos-system/user/CommandRouter/ProductSubscriptionHandler
[DEBUG][17-07-2017 23:05:39][Thread 0003][akka://pos-system/user/CommandRouter] *Unhandled message from akka://pos-system/temp/d* : Documents.Commands.AddProductSubscription
[DEBUG][17-07-2017 23:05:39][Thread 0007][akka://pos-system/user/CommandRouter/ProductSubscriptionHandler] Started (Consumers.Service.Commands.ProductSubscriptionHandler)

所以,事实证明我的问题有一个更简单(并且有效)的解决方案:只需在 CommandRouter 构造函数中注册并启动所有路由 actor,而不是每次接收。

现在我的代码看起来也简单多了:

CommandRouter:

public class CommandRouterActor : UntypedActor
{
    public Dictionary<Type, IActorRef> RoutingTable { get; }
    private ILoggingAdapter _log = Context.GetLogger(new SerilogLogMessageFormatter());

    public CommandRouterActor(IActorResolver resolver)
    {
        var props = resolver.CreateCommandHandlerProps();
        RoutingTable = props.ToDictionary(k => k.Item1, v => Context.ActorOf(v.Item2, $"CommandHandler-{v.Item1.Name}"));
    }

    protected override void OnReceive(object message)
    {
        _log.Info("Routing command {cmd}", message);
        var typeKey = message.GetType();

        if (!RoutingTable.ContainsKey(typeKey))
        {
                Sender?.Tell(Response.WithException(
                    new RoutingException(
                        $"Could not route message to routee. No routees found for message type {typeKey.FullName}")));

                _log.Info("Could not route command {cmd}, no routes found", message);
        }

        RoutingTable[typeKey].Forward(message);
    }

    protected override SupervisorStrategy SupervisorStrategy()
    {
        return new OneForOneStrategy(x => Directive.Restart);
    }
}

而我的 ActorResolver(在上面的 ctor 中使用)只是 IHandleCommand<>:

    public IEnumerable<Tuple<Type, Props>> CreateCommandHandlerProps()
    {
        var handlerTypes =
            _container.Model.AllInstances.Where(
                    i =>
                        i.PluginType.IsGenericType && i.PluginType.GetGenericTypeDefinition() ==
                        typeof(IHandleCommand<>))
                .Select(m => m.PluginType);

        foreach (var handler in handlerTypes)
        {
            yield return new Tuple<Type, Props>(handler.GenericTypeArguments.First(), _resolver.Create(handler));
        }
    }