Scala使用Akka模拟RPC机制代码

时间:2023-03-08 18:58:48
Scala使用Akka模拟RPC机制代码

上代码:  另一个版本(自己加注释):http://www.cnblogs.com/DreamDrive/p/6740440.html

RemoteMessage.scala

trait RemoteMessage extends Serializable

//Worker -> Master
case class RegisterWorker(id: String, memory: Int, cores: Int) extends RemoteMessage case class Heartbeat(id: String) extends RemoteMessage //Master -> Worker
case class RegisteredWorker(masterUrl: String) extends RemoteMessage //Worker -> self
case object SendHeartbeat // Master -> self
case object CheckTimeOutWorker

WorkerInfo.scala

class WorkerInfo(val id: String, val memory: Int, val cores: Int) {

  // 上一次心跳
var lastHeartbeatTime : Long = _
}

Worker.scala

import java.util.UUID

import akka.actor.{Actor, ActorSelection, ActorSystem, Props}
import com.typesafe.config.ConfigFactory
import scala.concurrent.duration._ class Worker(val masterHost: String, val masterPort: Int, val memory: Int, val cores: Int) extends Actor{ var master : ActorSelection = _
val workerId = UUID.randomUUID().toString
val HEART_INTERVAL = 10000 //
override def preStart(): Unit = {
//跟Master建立连接
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 = {
case RegisteredWorker(masterUrl) => {
println(masterUrl)
//启动定时器发送心跳
import context.dispatcher
//多长时间后执行 单位,多长时间执行一次 单位, 消息的接受者(直接给master发不好, 先给自己发送消息, 以后可以做下判断, 什么情况下再发送消息), 信息
context.system.scheduler.schedule(0 millis, HEART_INTERVAL millis, self, SendHeartbeat)
} case SendHeartbeat => {
println("send heartbeat to master")
master ! Heartbeat(workerId)
}
}
} object Worker {
def main(args: Array[String]) {
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
// 准备配置
val configStr =
s"""
|akka.actor.provider = "akka.remote.RemoteActorRefProvider"
|akka.remote.netty.tcp.hostname = "$host"
|akka.remote.netty.tcp.port = "$port"
""".stripMargin
val config = ConfigFactory.parseString(configStr)
//ActorSystem老大,辅助创建和监控下面的Actor,他是单例的
val actorSystem = ActorSystem("WorkerSystem", config)
actorSystem.actorOf(Props(new Worker(masterHost, masterPort, memory, cores)), "Worker")
actorSystem.awaitTermination()
}
}

Master.scala

import akka.actor.{Actor, ActorSystem, Props}
import com.typesafe.config.ConfigFactory import scala.collection.mutable
import scala.concurrent.duration._
class Master(val host: String, val port: Int) extends Actor { // workerId -> WorkerInfo
val idToWorker = new mutable.HashMap[String, WorkerInfo]()
// WorkerInfo
val workers = new mutable.HashSet[WorkerInfo]() //使用set删除快, 也可用linkList
//超时检查的间隔
val CHECK_INTERVAL = 15000//这个时间间隔一定要大于心跳的时间间隔. override def preStart(): Unit = {
println("preStart invoked")
//导入隐式转换
import context.dispatcher //使用timer太low了, 可以使用akka的, 使用定时器, 要导入这个包
context.system.scheduler.schedule(0 millis, CHECK_INTERVAL millis, self, CheckTimeOutWorker)
} // 用于接收消息
override def receive: Receive = {
case RegisterWorker(id, memory, cores) => {
//判断一下,是不是已经注册过
if(!idToWorker.contains(id)){
//把Worker的信息封装起来保存到内存当中
val workerInfo = new WorkerInfo(id, memory, cores)
idToWorker(id) = workerInfo
workers += workerInfo
sender ! RegisteredWorker(s"akka.tcp://MasterSystem@$host:$port/user/Master")//通知worker注册
}
}
case Heartbeat(id) => {
if(idToWorker.contains(id)){
val workerInfo = idToWorker(id)
//报活
val currentTime = System.currentTimeMillis()
workerInfo.lastHeartbeatTime = currentTime
}
} case CheckTimeOutWorker => {
val currentTime = System.currentTimeMillis()
val toRemove = workers.filter(x => currentTime - x.lastHeartbeatTime > CHECK_INTERVAL)
for(w <- toRemove) {
workers -= w
idToWorker -= w.id
}
println(workers.size)
}
}
} object Master {
def main(args: Array[String]) { val host = args(0)
val port = args(1).toInt
// 准备配置
val configStr =
s"""
|akka.actor.provider = "akka.remote.RemoteActorRefProvider"
|akka.remote.netty.tcp.hostname = "$host"
|akka.remote.netty.tcp.port = "$port"
""".stripMargin
val config = ConfigFactory.parseString(configStr)
//ActorSystem老大,辅助创建和监控下面的Actor,他是单例的
val actorSystem = ActorSystem("MasterSystem", config)
//创建Actor
val master = actorSystem.actorOf(Props(new Master(host, port)), "Master")
actorSystem.awaitTermination()
}
}