如何在Apache Spark和Scala中度量并行和顺序执行时间

 def main(args: Array[String]): Unit = {

   val conf = new SparkConf().setAppName("ParallelExecutionTime").setMaster("local")

   val sc = new SparkContext(conf)

   val data = sc.parallelize(Seq(1, 2, 3, 4, 5))

   val startTime = System.currentTimeMillis()

   val result = data.map(_ * 2)

   val endTime = System.currentTimeMillis()

   val executionTime = endTime - startTime

   println(s"Parallel Execution Time: $executionTime ms")

 }

 def main(args: Array[String]): Unit = {

   val data = Seq(1, 2, 3, 4, 5)

   val startTime = System.currentTimeMillis()

   val result = data.map(_ * 2)

   val endTime = System.currentTimeMillis()

   val executionTime = endTime - startTime

   println(s"Sequential Execution Time: $executionTime ms")

 }