RestartSource.withBackoff永远不会结束

Question

我正在尝试使用Akka创建具有重试策略的Http客户端，在该策略中，我希望最大重试次数，然后返回错误。有此代码

private def makeRequest[T](system: ActorSystem,
                             host: String,
                             unmarshallFunc: ResponseEntity => Future[Either[ServiceNowAccessException, T]]): Future[Either[ServiceNowAccessException, T]] = {

    implicit val mat: Materializer =  Materializer(system)

    RestartSource.withBackoff(
      minBackoff = 10 seconds,
      maxBackoff = 10 seconds,
      randomFactor = 0.2,
      maxRestarts = 2
    ) { () =>
      Source.future(Http()(system).singleRequest(HttpRequest(uri = host)))
        .mapAsync(parallelism = 1) {
          case HttpResponse(OK, _, entity, _) => unmarshallFunc(entity)
          case HttpResponse(InternalServerError, _, _, _) =>
            Future(Left(ServiceNowAccessException(InternalServerError.intValue)))
          case HttpResponse(statusCode, _, _, _) =>
            Future(Left(ServiceNowAccessException(statusCode.intValue())))
        }
    }.runWith(Sink.head)
  }

maxRestarts之后，我无法强制执行该错误，并且它一直试图永久连接。

任何想法我的代码有什么问题

致谢。