Question

免责声明：我是Akka的新手：）

我试图在Akka中实现路由器，基本上是

收到消息
在字典中查找处理消息类型的IActorRef
如果未找到匹配项，请使用Akka.DI作为子actor创建一个并添加到词典
向该演员发送消息

这很好 - 第一次，但如果我尝试Tell（）或Ask（）路由器两次，第二条消息总是在流中以未处理的方式结束

我尝试在子actor中重写Unhandled（）并在那里放置一个断点，实际上是在第二条消息上被击中。

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());
    }
}

实际的儿童演员非常紧张：

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

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

在actor系统初始化之后调用整个事件，如下所示：

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

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

我一直在第二个（或任何后续）消息上收到此错误：＆＃34;来自...的未处理消息＆＃34;：

[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)

Answer 1

所以，事实证明我的问题有一个更简单（和工作）的解决方案：只需在CommandRouter构造函数中注册并启动所有routee actor，而不是per-receive。

所以现在我的代码看起来也更简单了：

<强> 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);
    }
}

我的 ActorResolver （在上面的ctor中使用）只是IHandleCommand<>的{{3}}：

    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));
        }
    }

第二条消息在我的Akka.Net演员中变为Unhandled，然后它似乎停止了

1 个答案: