12:43:45,821 AM [testsystem-akka.actor.default-dispatcher-5] [INFO] Slf4jLogger - Slf4jLogger started 12:43:46,120 AM [testsystem-akka.actor.default-dispatcher-7] [INFO] RepointableActorRef - akkaDeadLetter Message [java.lang.String] from Actor[akka://testsystem/system/testActor-30#-367921602] to Actor[akka://testsystem/user/pingpongactor#-1479208278] was not delivered. [1] dead letters encountered. If this is not an expected behavior then Actor[akka://testsystem/user/pingpongactor#-1479208278] 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'. 12:43:46,121 AM [testsystem-akka.actor.default-dispatcher-7] [INFO] CoordinatedShutdown - Running CoordinatedShutdown with reason [ActorSystemTerminateReason]