爲什麼akka路由器在啓動後會發送消息給死信？

Question

後不久我的應用程序啓動時我看到這在日誌中：

INFO akka.actor.DeadLetterActorRef - Message [java.lang.String] from Actor[akka://MyApp/user/sqs-poller/router#-923782747] to Actor[akka://MyApp/deadLetters] 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'. 

這是否意味着路由器發送關機命令？是否有可能會記錄死信？

Answer 1

如Akka doc中所述，此類死信警告通常無害。由於在doc所示，您可以配置如下被關閉期間記錄的是一紙空文量：

akka { 
    log-dead-letters = 10 
    log-dead-letters-during-shutdown = on 
} 

也有一些相關的router actor specific discussion可能會感興趣。