如下是通过Akka集群来关闭所有节点和SBR角色的代码示例：

1. 定义一个Actor，负责接收所有节点和SBR角色的状态，当它们不稳定时，停止所有节点和SBR角色。

  class NodeStateActor extends Actor {
    private var nodes = Set.empty[Address]
    private var sbr: Option[ActorRef] = None
    
    context.system.eventStream.subscribe(self, classOf[MemberEvent])
    
    override def receive: Receive = {
      case MemberUp(member)            => nodes = nodes + member.address
      case MemberExited(member)        => nodes = nodes - member.address
      case MemberRemoved(member, _)    => nodes = nodes - member.address
      case MemberDowned(member)        => nodes = nodes - member.address
      case CurrentClusterState(state)  => nodes = state.members.map(_.address).filter(_.hasLocalScope)
      case sbr: ActorRef               => this.sbr = Some(sbr)
      case StateCheck                  => checkState()
    }
    
    private def checkState(): Unit = {
      if (sbr.exists(!_.isTerminated) && nodes.nonEmpty) {
        val potentials = nodes.filter(!_.hasLocalScope)
        if (potentials.nonEmpty) {
          potentials.foreach(context.actorSelection(_).tell(PoisonPill, Actor.noSender))
          sbr.foreach(_.tell(PoisonPill, Actor.noSender))
        } else if (!nodes.exists(!_.hasLocalScope)) {
          sbr.foreach(_.tell(PoisonPill, Actor.noSender))
        }
      }
    }
    
  }

2. 在应用程序中创建一个ActorSystem，同时启用Akka集群，并将Actor部署到所有节点上。

    object Test extends App {
       val config = ConfigFactory.parseString("""
          akka {
            actor.provider = "cluster"
            remote.netty.tcp.port = 0
            cluster.roles=["sbr"]
          }
       """)
   
       val system = ActorSystem("test", config)
   
       val nodeStateActor = system.actor