scala – 只要演员被放入路由器就会遇到“死信”

class Printer extends Actor {
    def receive = {
        case m: SomeMessage => println( m.text )
        case _ =>
    }
}

我正在创建其中几个演员：

val actor4 = system.actorOf(Props[Printer],"t-4")
val actor5 = system.actorOf(Props[Printer],"t-5")
val actor6 = system.actorOf(Props[Printer],"t-6")

并将它们扔进矢量：

val routees2 = Vector[ActorRef](actor4,actor5,actor6)

我正在做以上操作,以便我可以将它们扔进路由器(并且它们将受路由器的控制).当我运行规范到目前为止,我没有任何问题.一旦我将它们放入路由器并运行规范我就遇到了问题.这是路由器：

val router = system.actorOf(Props[Printer].withRouter(
    BroadcastRouter(routees = routees2)),"router-to-transformers")

现在,当我运行规范时,我有各种各样的死信……

[INFO] [09/23/2013 17:10:21.468] [spider-akka.actor.default-dispatcher-6] [akka://spider/user/router-to-transformers] Message [akka.dispatch.sysmsg.DeathWatchNotification] from Actor[akka://spider/user/router-to-transformers#-1845250548] to Actor[akka://spider/user/rout
er-to-transformers#-1845250548] 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] [09/23/2013 17:10:21.468] [spider-akka.actor.default-dispatcher-6] [akka://spider/user/router-to-transformers] Message [akka.dispatch.sysmsg.DeathWatchNotification] from Actor[akka://spider/user/router-to-transformers#-1845250548] to Actor[akka://spider/user/rout
er-to-transformers#-1845250548] 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'.
[INFO] [09/23/2013 17:10:21.468] [spider-akka.actor.default-dispatcher-6] [akka://spider/user/router-to-transformers] Message [akka.dispatch.sysmsg.DeathWatchNotification] from Actor[akka://spider/user/router-to-transformers#-1845250548] to Actor[akka://spider/user/rout
er-to-transformers#-1845250548] was not delivered. [3] 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'.

对于我的生活,我无法弄清楚这里发生了什么.我添加了一个测试片段的链接.代码片段中的编号很奇怪,因为我已经删除了一堆被注释掉的不同尝试,以免杂乱无章.我专注于这个死信问题,因为我觉得当我添加更多演员并实际开始传递信息时,事情没有得到传递……
http://snipt.org/AhVf0

值得一提的是,这些演员都是本地人.我已经阅读了关于actor的一些信息,因为它被折旧了,我想知道这是否被使用,部分原因是什么导致了我的问题？这里有很多活动部件,而不是很多稳定,全面的文档.任何帮助将不胜感激.