override def preStart() {

    webUi = new WorkerWebUI(this, workDir, Some(webUiPort))

    webUi.bind()  //创建并绑定UI

    registerWithMaster()  //注册到Master

}

def tryRegisterAllMasters() {

    for (masterUrl <- masterUrls) {

    logInfo("Connecting to master " + masterUrl + "...")

    val actor = context.actorSelection(Master.toAkkaUrl(masterUrl))

    actor ! RegisterWorker(workerId, host, port, cores, memory, webUi.boundPort, publicAddress)

    }

}