带后退和重试限制的演员重试

Question

我需要在akka演员重试机制与增加时间之间的重试和最大重试限制。为此，我尝试使用AKKA提供的BackOffSupervisor模式。问题是，从我的测试来看，后退策略和重试限制似乎不起作用。又或者问题出在测试上？

class SomeActor extends AbstractActor {

private static int messageCounter = 0;

//return the message to sender
@Override
public void preRestart(final Throwable reason, final Optional<Object> message) {
    getSelf().tell(message.get(), getSender());
}


@Override
public Receive createReceive() {
    return receiveBuilder()
            .matchEquals("hello", message -> {
                messageCounter++;
                getSender().tell("response", getSelf());

                //Throw Exception at the first 5 messages
                if (messageCounter < 5) {
                    throw new Exception();
                }

            })
            .build();
}

private ActorRef createSupervisedActor(Class<? extends Actor> actorClass) {
    final Props someActorProps = Props.create(actorClass);

    final Props supervisorProps = BackoffSupervisor.props(
            Backoff.onStop(
                    someActorProps, //actor to be supervised
                    "someActor",
                    Duration.ofSeconds(10), //min back-off time
                    Duration.ofMinutes(2), // max back-off time
                    0.2, // back-off increase factor
                    10) // max retry limit
                    .withSupervisorStrategy(
                            new OneForOneStrategy(
                                    DeciderBuilder
                                            .match(Exception.class, e -> SupervisorStrategy.restart())
                                            .matchAny(o -> SupervisorStrategy.escalate())
                                            .build())
                    )
    );

    return testSystem.actorOf(supervisorProps);

}

和试验方法

    @Test
public void test() {
    new TestKit(testSystem) {{
        ActorRef actorRef = createSupervisedActor(SomeActor.class);

        actorRef.tell("hello", getRef());

        //Expect 5 responses in 1 second
        receiveN(5, Duration.ofSeconds(1));
    }};

}

测试结束得太快了。在不到一秒钟的时间里，从BackoffSupervisor的配置来看，我预计至少需要50多秒。

Answer 1

问题是由于以下原因造成的：

在子actor（在我的例子中是someActor）中抛出异常不由backoff.onstop处理，因此由正常的默认监督处理，这意味着立即重新启动。-https://github.com/akka/akka/issues/23406#issuecomment-372602568