监控Yarn上运行的Spark任务实例状态

可以通过要监控的任务列表，对比存活的Spark任务，不存在的可以通过短信或邮件的方式预警。获取Spark还在运行状态任务的示例代码：

private def yarn(): Unit = {
    val yarnConf = new YarnConfiguration()
    val yarnClient = YarnClient.createYarnClient()

    yarnClient.init(yarnConf)
    yarnClient.start()

    try {
      import scala.collection.JavaConversions._
      //YarnApplicationState有应用不同的运行状态，如RUNNING、FINISHED
      val applicationReports = yarnClient.getApplications(util.EnumSet.of(YarnApplicationState.RUNNING))

      applicationReports.foreach { ar =>
        //应用ID，spark.app.id
        println(s"appId ==> ${ar.getApplicationId}")
        //应用名字，spark.app.name
        println(s"name ==> ${ar.getName}")
        //应用所处队列，spark.yarn.queue
        println(s"queue ==> ${ar.getQueue}")
        //应用的用户
        println(s"user ==> ${ar.getUser}")
      }

    } catch {
      case e: Exception => e.printStackTrace()
    }

    yarnClient.stop()
 }