RemoteMessage.scala
//对象要序列化才能通过网络传输 这个地方没有大括号....这有这个extends声明
trait RemoteMessage extends Serializable //Worker ->(发送给) Master Worker给Master节点发送注册消息
case class RegisterWorker(id:String, memory:Int, scores:Int ) extends RemoteMessage //接收已经在Master注册过的Worker定时发送来的心跳 Woker->Master
case class Heartbeat(id:String) extends RemoteMessage //Master -> Worker Master反馈给Worker已经注册的Worker有哪些
case class RegisteredWorker(masterUrl:String) extends RemoteMessage //Worker -> self //Worker先向自己发送一下心跳,这个地方可以做一下判断,根据实际情况,定义什么时候向Master发送消息
//在这个样例类中发送给Master的心跳 case class Heartbeat
case object SendHeartbeat //Master -> self Master自检查看Worker的状态
case object CheckTimeOutWorker
WorkerInfo.scala
class WorkerInfo(val id:String,val memory:Int,val scores:Int) {
//记录上一次心跳
var lastHeartbeatTime : Long = _
}Worker.scala
import java.util.UUID
import com.typesafe.config.ConfigFactory
import akka.actor.Actor
import akka.actor.ActorSystem
import akka.actor.Props
import akka.actor.ActorSelection
import scala.concurrent.duration._ //如果不引入这个包 在 context.system.scheduler.schedule 中的mills 地方会报错 //使用Akka框架来实现RCP不同进程之间的方法调用 导入Actor是导入的akka包下的
//在Worker类上定义一个主构造器
class Worker (val masterHost:String ,val masterPort:Int ,val memory:Int ,val cores: Int) extends Actor {
var master : ActorSelection = _
//记录Worker从节点的id
val workerId = UUID.randomUUID().toString()
//记录Worker从节点的发送心跳的时间间隔
val HEART_INTERVAL = 10000 //preStart()方法在构造器之后,在receive之前执行 actorOf()方法执行 就会执行生命周期方法
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 = {
//Master对注册的Worker存储注册之后需要向Worker发送消息 来说明该Woker注册成功
//此处是Worker节点接收到Master节点的反馈消息
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), 消息
context.system.scheduler.schedule(0 millis, HEART_INTERVAL millis, self, SendHeartbeat)
}
//Worker先向自己self发送一下心跳,这个地方可以做一下判断,根据实际情况,定义什么时候向Master发送消息
case SendHeartbeat =>{
println("send heartbeat to Master")
master ! Heartbeat(workerId)
}
}
}
object Worker{
def main(args: Array[String]): Unit = {
//从传入的参数列表中取得
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
//为了通过ActorSystem老大来获得Actor 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是所有Actor的老大,辅助创建和监控下面的Actor, 该老大是单例的.
//得到该老大的对象需要一个名字和配置对象config
val actorSystem = ActorSystem("WorkerSystem",config)
//actorOf方法执行,就会执行生命周期方法
actorSystem.actorOf(Props(new Worker(masterHost, masterPort, memory, cores)),"Worker")
actorSystem.awaitTermination()
}
}
Master.scala
import com.typesafe.config.ConfigFactory import akka.actor.Actor
import akka.actor.ActorSystem
import akka.actor.Props
import scala.collection.mutable
import scala.concurrent.duration._ class Master(val host:String,val port:Int) extends Actor{ //定义一个HashMap用来存储注册Worker的信息
val idToWorkerHashMap = new mutable.HashMap[String,WorkerInfo]()
//定义一个HashSet用于存储 注册的Worker对象 WorkerInfo
val workersSet = new mutable.HashSet[WorkerInfo]() //使用set删除快, 也可用linkList
//超时检查的间隔 这个时间间隔一定要大于Worker向Master发送心跳的时间间隔.
val CHECK_INTERVAL = 15000 override def preStart() :Unit = {
println("preStart invoked")
//导入隐式转换
//使用timer太low了,可以使用akka的定时器,需要导入这个包
import context.dispatcher
context.system.scheduler.schedule(0 millis, CHECK_INTERVAL millis, self, CheckTimeOutWorker)
}
//接收Worker发送来的消息 可以有注册RegisterWorker 心跳Heartbeat
override def receive :Receive = {
case RegisterWorker(id,memory,cores) =>{
//判断该Worker是否已经注册过
if(!idToWorkerHashMap.contains(id)){
//把Worker的信息封装起来保存到内存中
val workerInfo = new WorkerInfo(id,memory,cores)
//以id为键 worker对象为值 添加到该idToWorker的HashMap对象中
idToWorkerHashMap(id) = workerInfo
//把workerInfo对象放到存储Woker的HashSet中
workersSet += workerInfo
//对注册的Worker存储注册之后需要向Worker发送消息 来说明该Woker注册成功
sender ! RegisteredWorker(s"akka.tcp://MasterSystem@$host:$port/user/Master")//通知worker注册
}
}
//接收已经在Master注册过的Worker定时发送来的心跳
case Heartbeat(id) =>{
if(idToWorkerHashMap.contains(id)){
val workerInfo = idToWorkerHashMap(id)
//报活 把该Worker给Master心跳的时间记录下来
val currentTime = System.currentTimeMillis()
workerInfo.lastHeartbeatTime = currentTime
}
}
//Master节点主动检测在Master自己这里注册Worker节点的存活状态
case CheckTimeOutWorker =>{
val currentTime = System.currentTimeMillis();
//如果当前时间和最近一次心跳时间的差值大于检测的时间间隔 就要干掉这个Worker
val toRemove = workersSet.filter(x => currentTime - x.lastHeartbeatTime > CHECK_INTERVAL)
for(w <- toRemove){
workersSet -= w
idToWorkerHashMap -= w.id
}
println(workersSet.size)
}
}
} object Master{
def main(args: Array[String]): Unit = {
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
//ConfigFactory 既有parseString 也有parseFile
val config = ConfigFactory.parseString(configStr)
//ActorSystem是所有Actor的老大,辅助创建和监控下面的所有Actor,它是单例的
val actorSystem = ActorSystem("MasterSystem",config)
val master = actorSystem.actorOf(Props(new Master(host,port)),"Master")
actorSystem.awaitTermination()
}
}