我设置了一个断点here：
package sample.persistence
//#persistent-actor-example
import akka.actor._
import akka.persistence._
case class Cmd(data: String)
case class Evt(data: String)
case class ExampleState(events: List[String] = Nil) {
def updated(evt: Evt): ExampleState = copy(evt.data :: events)
def size: Int = events.length
override def toString: String = events.reverse.toString
}
class ExamplePersistentActor extends PersistentActor {
override def persistenceId = "sample-id-1"
var state = ExampleState()
def updateState(event: Evt): Unit =
state = state.updated(event)
def numEvents =
state.size
val receiveRecover: Receive = {
case evt: Evt => updateState(evt)
case SnapshotOffer(_, snapshot: ExampleState) => state = snapshot
^^^^^^^ BREAKPOINT ^^^^^
}
val receiveCommand: Receive = {
case Cmd(data) =>
persist(Evt(s"${data}-${numEvents}"))(updateState)
persist(Evt(s"${data}-${numEvents + 1}")) { event =>
updateState(event)
context.system.eventStream.publish(event)
}
case "snap" => saveSnapshot(state)
case "print" => println(state)
}
}
//#persistent-actor-example
object PersistentActorExample extends App {
val system = ActorSystem("example")
val persistentActor = system.actorOf(Props[ExamplePersistentActor], "persistentActor-4-scala")
persistentActor ! Cmd("foo")
persistentActor ! Cmd("baz")
persistentActor ! Cmd("bar")
persistentActor ! "snap"
persistentActor ! Cmd("buzz")
persistentActor ! "print"
Thread.sleep(10000)
system.terminate()
}
我得到了：
[INFO] [03/30/2017 22:53:40.141] [example-akka.actor.default-dispatcher-3] [akka://example/user/persistentActor-4-scala] Message [java.lang.String] from Actor[akka://example/deadLetters] to Actor[akka://example/user/persistentActor-4-scala#-1598116294] 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] [03/30/2017 22:53:40.142] [example-akka.actor.default-dispatcher-3] [akka://example/user/persistentActor-4-scala] Message [sample.persistence.Cmd] from Actor[akka://example/deadLetters] to Actor[akka://example/user/persistentActor-4-scala#-1598116294] 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] [03/30/2017 22:53:40.142] [example-akka.actor.default-dispatcher-3] [akka://example/user/persistentActor-4-scala] Message [sample.persistence.Cmd] from Actor[akka://example/deadLetters] to Actor[akka://example/user/persistentActor-4-scala#-1598116294] 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'.
[INFO] [03/30/2017 22:53:40.142] [example-akka.actor.default-dispatcher-3] [akka://example/user/persistentActor-4-scala] Message [sample.persistence.Cmd] from Actor[akka://example/deadLetters] to Actor[akka://example/user/persistentActor-4-scala#-1598116294] was not delivered. [4] 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] [03/30/2017 22:53:40.142] [example-akka.actor.default-dispatcher-3] [akka://example/user/persistentActor-4-scala] Message [java.lang.String] from Actor[akka://example/deadLetters] to Actor[akka://example/user/persistentActor-4-scala#-1598116294] was not delivered. [5] 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] [03/30/2017 22:53:40.142] [example-akka.actor.default-dispatcher-9] [akka://example/user/persistentActor-4-scala] Message [sample.persistence.Cmd] from Actor[akka://example/deadLetters] to Actor[akka://example/user/persistentActor-4-scala#-1598116294] was not delivered. [6] 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] [03/30/2017 22:53:40.143] [example-akka.actor.default-dispatcher-9] [akka://example/user/persistentActor-4-scala] Message [java.lang.String] from Actor[akka://example/deadLetters] to Actor[akka://example/user/persistentActor-4-scala#-1598116294] was not delivered. [7] 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'.
Disconnected from the target VM, address: '127.0.0.1:53432', transport: 'socket'
Process finished with exit code 0
为什么会这样？
为什么我会收到死信？
是因为消息超时吗？
如果是，有没有办法将超时间隔设置为无限？
如果原因是别的，那么有没有办法确保使用断点调试不会出现死信？