Spark分析之Master

override def preStart() {
    logInfo("Starting Spark master at " + masterUrl)
    webUi.bind()    //绑定WEBUI
    masterWebUiUrl = "http://" + masterPublicAddress + ":" + webUi.boundPort
    context.system.scheduler.schedule(0 millis, WORKER_TIMEOUT millis, self, CheckForWorkerTimeOut) //定时检查超时未发送心跳的Worker

    masterMetricsSystem.registerSource(masterSource)
    masterMetricsSystem.start()
    applicationMetricsSystem.start()

    //用作master recover
    persistenceEngine = RECOVERY_MODE match {
    case "ZOOKEEPER" =>
        logInfo("Persisting recovery state to ZooKeeper")
        new ZooKeeperPersistenceEngine(SerializationExtension(context.system), conf)
    case "FILESYSTEM" =>
        logInfo("Persisting recovery state to directory: " + RECOVERY_DIR)
        new FileSystemPersistenceEngine(RECOVERY_DIR, SerializationExtension(context.system))
    case _ =>
        new BlackHolePersistenceEngine()
    }
  
    //用作master的leader选举
    leaderElectionAgent = RECOVERY_MODE match {
    case "ZOOKEEPER" =>
        context.actorOf(Props(classOf[ZooKeeperLeaderElectionAgent], self, masterUrl, conf))
    case _ =>
        context.actorOf(Props(classOf[MonarchyLeaderAgent], self))
    }
}

override def receive = {
　　case RegisterWorker

   case RequestSubmitDriver

   case RegisterApplication

   case Heartbeat

   case ExecutorStateChanged

   ......
}

Master的主要功能总结：

1、Master的Leader选举；

2、对Driver、Worker、Application的管理

　　1）Driver：RequestSubmitDriver/RequestKillDriver/RequestDriverStatus/DriverStateChanged

　　2）Worker：RegisterWorker/Heartbeat/WorkerSchedulerStateResponse/CheckForWorkerTimeOut/ExecutorStateChanged

　　3）Application：RegisterApplication