对RDD分区的理解

举个例子：

val logFile = "file:///home/soyo/桌面/6.txt" 
    val conf = new SparkConf().setAppName("Simple Application")
    val sc = new SparkContext(conf)
    val RDD =sc.textFile(logFile)

    RDD.saveAsTextFile("file:////home/soyo/桌面/667.txt")   

    val repartitionedRDD=context.repartition(8) //控制RDD分区的个数

    repartitionedRDD.saveAsTextFile("file:////home/soyo/桌面/668.txt")

667.txt:                                        

part-00000    _SUCCESS

668.txt:

part-00000   part-00001    part-00002    part-00003     part-00004    part-00005   part-00006    part-00007     _SUCCESS

如果设置.setMaster("local[2]")默认最少是2个分区，别的类同