使用Akka实现一个简单的RPC框架（二）

需求以及实现思路如下

至于Master与Worker的编写参考使用Akka实现简单rpc（一）

1、Master类

/**
  * Created by 12706 on 2017/11/29.
  */
class Master(val host : String, val port : Int) extends Actor{
  //key为workerId，value为worker的信息
  val regWorkersMap = new mutable.HashMap[String,WorkerInfo]()

  val regWorkersSet = new mutable.HashSet[WorkerInfo]()

  //定时检查worker是否超时，时间15秒（即15秒检查一次）,一定要大于worker发送心跳的间隔
  val CHECK_WORKER_TIMEOUT : Long = 15000

  //初始化方法
  override def preStart(): Unit = {
    //定时检查worker，如果超时那么排除掉该worker,导入隐士转换与import scala.concurrent.duration._
    import context.dispatcher
    context.system.scheduler.schedule(0 millis, CHECK_WORKER_TIMEOUT millis, self ,CheckWorker)
  }

  //不停地接收消息
  override def receive: Receive = {
    //接收到worker的注册消息
    case RegisterWorker(workerId,memory,cores) => {
      if (!regWorkersMap.contains(workerId)){
        //该worker还没注册，将该worker信息保存（保存到map和set中）起来
        val workerInfo = new WorkerInfo(workerId,memory,cores)
        regWorkersMap.put(workerId,workerInfo)
        regWorkersSet.add(workerInfo)
        //向worker返回注册成功信息,需要告诉worker该master的地址
        sender ! RegisteredSucceed(s"akka.tcp://MasterSystem@$host:$port/user/master")
      }
    }
      //接收到worker发送的心跳信息,重新设置该worker的最后报活时间
    case HeartBeat(workerId) => {
      val currentTime = System.currentTimeMillis()
      val workerInfo = regWorkersMap(workerId)
      //修改map中的workerInfo时，由于set中对应的那个workerInfo与map中的都是指向同一内存单元的，所以值也等于发生了改变
      workerInfo.lastBeatTime = currentTime
    }
    case CheckWorker => {
      val currentTime = System.currentTimeMillis()
      //最后一次报活时间到现在的时间间隔超过了15秒的worker是集合
      val toRemoveWorkers = regWorkersSet.filter(worker => currentTime - worker.lastBeatTime > CHECK_WORKER_TIMEOUT)
      for (worker <- toRemoveWorkers) {
        //超过的这些worker是全部移除
        regWorkersSet.remove(worker)
        regWorkersMap.remove(worker.workerId)
      }
      println("存活的workers个数:" + regWorkersSet.size)
    }
  }

}

object Master {
  def main(args: Array[String]): Unit = {

    //连接地址和端口号
    val host = args(0)
    val port = args(1).toInt
    val configStr =
      s"""
        |akka.actor.provider = "akka.remote.RemoteActorRefProvider"
        |akka.remote.netty.tcp.hostname = "$host"
        |akka.remote.netty.tcp.port = "$port"
      """.stripMargin
    //传入配置参数获取配置
    val config = ConfigFactory.parseString(configStr)
    //获取ActorSystem，指定名称和配置
    val masterSystem = ActorSystem("MasterSystem",config)
    //创建Actor
    val master = masterSystem.actorOf(Props(new Master(host,port)),"master")
    masterSystem.awaitTermination()
  }
}

2、Worker类

class Worker(val masterHost : String,val masterPort : Int, val memory : Int, val cores : Int) extends Actor{

  var master : ActorSelection =_
  val workerId : String = UUID.randomUUID().toString.replace("-","")
  //向Master发送心跳的间隔10s
  val SEND_HEARTBEAT_INTERVAL : Long = 10000

  override def preStart(): Unit = {
    //与Master建立连接，拿到master引用
    master = context.actorSelection(s"akka.tcp://MasterSystem@$masterHost:$masterPort/user/master")
    //向Master发送注册消息
    master ! RegisterWorker(workerId,memory,cores)
  }

  override def receive: Receive = {
    //收到Master返回的注册成功信息
    case RegisteredSucceed(masterUrl) => {
      //定时向Master发送心跳,用来报活
      // 需要导入隐式转换,还需要导入包scala.concurrent.duration._
      import context.dispatcher
      //以上拿到的master引用的类型跟这里第三个参数指定的发送目标类型不一致，所以发送给worker自己
      //第二个参数为发送时间间隔，最后一个是发送的信息,发送给自己的话还可以自己做一些信息检查再发送给Master
      context.system.scheduler.schedule(0 millis,SEND_HEARTBEAT_INTERVAL millis,self,CheckWorkerSelf)
    }
    case CheckWorkerSelf => {
      println(s"$workerId:worker向master报活")
      master ! HeartBeat(workerId)
    }

    case "reply" => {
      println("收到Master消息")
    }
  }
}

object Worker {
  def main(args: Array[String]): Unit = {
    val host = args(0)
    val port = args(1).toInt
    val masterHost = args(2)
    val masterPort = args(3).toInt
    val memory = args(4).toInt
    val cores = args(5).toInt
    val configStr =
      s"""
         |akka.actor.provider = "akka.remote.RemoteActorRefProvider"
         |akka.remote.netty.tcp.hostname = "$host"
         |akka.remote.netty.tcp.port = "$port"
      """.stripMargin
    //传入配置参数获取配置
    val config = ConfigFactory.parseString(configStr)
    //获取ActorSystem，指定名称和配置
    val workerSystem = ActorSystem("WorkerSystem",config)
    //创建Actor
    val actor = workerSystem.actorOf(Props(new Worker(masterHost,masterPort,memory,cores)),"worker")
    workerSystem.awaitTermination()
  }
}

3、WorkerInfo类

/**
  * 封装了worker的信息类
  * Created by 12706 on 2017/11/30.
  */
class WorkerInfo(val workerId : String,val memory : Int, val cores : Int) {
  var lastBeatTime : Long = _
}

4、样例类

//需要进行网络传输
trait RemoteMessage extends Serializable

//Worker想Master发送的注册消息 workerId,内存，核数,由于需要进行网络传输所以需要继承RemoteMessage
case class RegisterWorker(val workerId : String, val memory : Int, val cores : Int) extends RemoteMessage

//Master想Worker发送的注册成功消息
case class RegisteredSucceed(val masterUrl : String)

case object CheckWorkerSelf

//Worker想Master发送心跳
case class HeartBeat(val workerId : String) extends RemoteMessage

case object CheckWorker

分别指定两个主类，指定主类为

<mainClass>cn.hfut.rpc.Master</mainClass>

时，将打的包放到windows的D盘下，命令行输入

D:\>java -jar my-akka-2.0.jar 192.168.191.2 8080
[INFO] [11/30/2017 13:24:19.554] [main] [Remoting] Starting remoting
[INFO] [11/30/2017 13:24:19.975] [main] [Remoting] Remoting started; listening on addresses :[akka.tcp://[email protected]:8080]
[INFO] [11/30/2017 13:24:19.977] [main] [Remoting] Remoting now listens on addresses: [akka.tcp://[email protected]:8080]
存活的workers个数:0
存活的workers个数:0
存活的workers个数:0
存活的workers个数:0

可以发现每隔15秒回检查一次，打印存活的worker数。

再指定主类为

<mainClass>cn.hfut.rpc.Worker</mainClass>

时，打包上传到两台linux机器
2机器命令行输入

mini1 机器

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[root@mini1 ~]# java -jar my-akka-2.0.jar mini1 8081 192.168.191.2 8080 102400 4
[INFO] [11/30/2017 21:27:51.136] [main] [Remoting] Starting remoting
[INFO] [11/30/2017 21:27:51.352] [main] [Remoting] Remoting started; listening on addresses :[akka.tcp://WorkerSystem@mini1:8081]
[INFO] [11/30/2017 21:27:51.353] [main] [Remoting] Remoting now listens on addresses: [akka.tcp://WorkerSystem@mini1:8081]
4e9b8e9bfc0e44e590517831b4ce7d29:worker向master报活
4e9b8e9bfc0e44e590517831b4ce7d29:worker向master报活

mini2机器

[root@mini2 ~]#  java -jar my-akka-2.0.jar mini2 8082 192.168.191.2 8080 102400 4
[INFO] [11/23/2017 17:47:56.166] [main] [Remoting] Starting remoting
[INFO] [11/23/2017 17:47:56.399] [main] [Remoting] Remoting started; listening on addresses :[akka.tcp://WorkerSystem@mini2:8082]
[INFO] [11/23/2017 17:47:56.399] [main] [Remoting] Remoting now listens on addresses: [akka.tcp://WorkerSystem@mini2:8082]
0e33270b6fa843b684088d7125fe0ca5:worker向master报活
0e33270b6fa843b684088d7125fe0ca5:worker向master报活

发现两台机器每隔10秒就向master发送心跳（报活）
再去window是上命令行查看

存活的workers个数:1
存活的workers个数:1
存活的workers个数:2
存活的workers个数:2