Global sequential access of elements in RDD

[Wush Wu]

Dear all,

I want to implement some sequential algorithm on RDD.

For example:

val conf = new SparkConf()
  conf.setMaster("local[2]").
  setAppName("SequentialSuite")
val sc = new SparkContext(conf)
val rdd = sc.
   parallelize(Array(1, 3, 2, 7, 1, 4, 2, 5, 1, 8, 9), 2).
   sortBy(x => x, true)
rdd.foreach(println)

I want to see the ordered number on my screen, but it shows unordered
integers. The two partitions execute the println simultaneously.

How do I make the RDD execute a function globally sequential?

Best,
Wush