Akka的文档正确引用说:
重启期间的精确事件顺序如下: 暂停演员(这意味着它不会处理正常 消息,直到恢复),并递归暂停所有孩子。
误导性的一句话说:
恢复演员恢复其所有下属,重新启动演员 需要重新启动其所有下属,同样终止一个actor也将终止其所有下属
我怀疑我们有责任在preStart
方法中创建子(ren),因为Akka的术语 RESTART 不是reSTART,除非你在他们的中递归和明确地创建子项父preStart()
方法。
示例(使用Akka 2.0& 2.2-SNAPSHOT):无论我尝试什么,孩子总是刚刚停止,从未在此测试用例中重新启动。我创建了Supervisor
- > First
- > Second
关系并在Supervisor
中抛出异常。会发生什么情况supervisor
重新启动,First
& Second
停了。
test("restart test") {
val system = ActorSystem("test")
val supervisor = system.actorOf(Props(new Supervisor), "supervisor")
supervisor ! CREATE(Props(new First), "first")
Thread.sleep(500)
val first = system.actorFor("akka://test/user/supervisor/first")
first ! CREATE(Props(new Second), "second")
Thread.sleep(500)
supervisor ! WTF
Thread.sleep(20000)
}
case object WTF
case class CREATE(p: Props, name: String)
class Supervisor extends Actor {
override val supervisorStrategy =
OneForOneStrategy(maxNrOfRetries = 10) {
case _: IllegalStateException => Restart
case _: IllegalArgumentException => Stop
case _: Exception => Restart
}
override def preStart() {
println(s"$self starts")
}
override def postStop() {
println(s"$self stopped")
}
override def receive = {
case WTF => println("throwing exception"); throw new IllegalStateException()
case CREATE(p, name) => context.actorOf(p, name)
}
}
class First extends Actor {
override def preStart() {
println(s"$self starts")
}
override def postStop() {
println(s"$self stopped")
}
override def receive = {
case WTF => println("throwing exception"); throw new IllegalStateException()
case CREATE(p, name) => context.actorOf(p, name)
}
}
class Second extends Actor {
override def preStart() {
println(s"$self starts")
}
override def postStop() {
println(s"$self stopped")
}
override def receive = {
case WTF => println("throwing exception"); throw new IllegalStateException()
case CREATE => sender ! "ok"
}
}
演员[akka:// test / user / supervisor#1599926629]开始 演员[akka:// test / user / supervisor / first#2012011668]开始 演员[akka:// test / user / supervisor / first / second#1750038710]开始
抛出异常演员[akka:// test / user / supervisor#1599926629] 停止[错误] [06/26/2013 11:11:16.899] [test-akka.actor.default-dispatcher-4] [akka:// test / user / supervisor] null java.lang.IllegalStateException at com.fg.mail.smtp.IntegrationSuite $主管$$ anonfun $获得$ 1.applyOrElse(IntegrationSuite.scala:40) at akka.actor.ActorCell.receiveMessage(ActorCell.scala:498)at at at akka.actor.ActorCell.invoke(ActorCell.scala:456)at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:237)at akka.dispatch.Mailbox.run(Mailbox.scala:219)at akka.dispatch.ForkJoinExecutorConfigurator $ AkkaForkJoinTask.exec(AbstractDispatcher.scala:386) 在 scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:262) 在 scala.concurrent.forkjoin.ForkJoinPool $ WorkQueue.runTask(ForkJoinPool.java:975) 在 scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1478) 在 scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:104)
演员[akka:// test / user / supervisor / first / second#1750038710]停了下来 演员[akka:// test / user / supervisor / first#2012011668]停了下来 演员[akka:// test / user / supervisor#1599926629]开始
答案 0 :(得分:6)
你的怀疑是正确的。如果您仔细查看http://doc.akka.io/docs/akka/snapshot/general/supervision.html上重启过程的7步说明,您会看到:
2。 ...默认为所有孩子发送终止请求......
和
6。向所有未被杀死的孩子发送重启请求
所以,你需要覆盖父的preRestart
钩子来阻止Akka杀死孩子,或者覆盖postRestart
来重新创建刚杀死的所有孩子。
您选择的确实取决于您的应用程序的语义。有时杀死整个层次结构并从空白的平板开始是有用的,有时候不是。