我正在使用最新的akka 2.5.21和akka-http 10.1.7
当WS客户端不正常断开连接时，我的WS服务器将抛出以下信息日志。
结果，即使将存活时间设置为1s，WS服务器也无法检测到失败的WS连接。
[15-02-2019 17:58:19.853][INFO] a.a.LocalActorRef: Message [akka.io.TcpConnection$Unregistered$] from Actor[akka://router_system/system/IO-TCP/selectors/$a/3#1959776912] to Actor[akka://router_system/system/IO-TCP/selectors/$a/3#1959776912] was not delivered. [1] dead letters encountered. If this is not an expected behavior, then [Actor[akka://router_system/system/IO-TCP/selectors/$a/3#1959776912]] may have terminated unexpectedly, This logging can be turned off or adjusted with configuration settings 'akka.log-dead-letters' and 'akka.log-dead-letters-during-shutdown'.
[15-02-2019 17:58:19.854][INFO] a.a.LocalActorRef: Message [akka.io.TcpConnection$Unregistered$] from Actor[akka://router_system/system/IO-TCP/selectors/$a/0#1692731895] to Actor[akka://router_system/system/IO-TCP/selectors/$a/0#1692731895] was not delivered. [2] dead letters encountered. If this is not an expected behavior, then [Actor[akka://router_system/system/IO-TCP/selectors/$a/0#1692731895]] may have terminated unexpectedly, This logging can be turned off or adjusted with configuration settings 'akka.log-dead-letters' and 'akka.log-dead-letters-during-shutdown'.
[15-02-2019 17:58:19.854][INFO] a.a.LocalActorRef: Message [akka.io.TcpConnection$Unregistered$] from Actor[akka://router_system/system/IO-TCP/selectors/$a/2#-827155178] to Actor[akka://router_system/system/IO-TCP/selectors/$a/2#-827155178] was not delivered. [3] dead letters encountered. If this is not an expected behavior, then [Actor[akka://router_system/system/IO-TCP/selectors/$a/2#-827155178]] may have terminated unexpectedly, This logging can be turned off or adjusted with configuration settings 'akka.log-dead-letters' and 'akka.log-dead-letters-during-shutdown'.
[15-02-2019 17:58:19.854][INFO] a.a.LocalActorRef: Message [akka.io.TcpConnection$Unregistered$] from Actor[akka://router_system/system/IO-TCP/selectors/$a/1#1382800995] to Actor[akka://router_system/system/IO-TCP/selectors/$a/1#1382800995] was not delivered. [4] dead letters encountered. If this is not an expected behavior, then [Actor[akka://router_system/system/IO-TCP/selectors/$a/1#1382800995]] may have terminated unexpectedly, This logging can be turned off or adjusted with configuration settings 'akka.log-dead-letters' and 'akka.log-dead-letters-during-shutdown'.