val a = List((3, 1.0), (2, 2.0), (4, 2.0), (1,0.0))
val rdd = sc.parallelize(a)

val b = ((rdd.takeOrdered(2).zipWithIndex.map{case (k,v) => (v,k)}).toList find {x => x._1 == 1}).map(x => x._2).map(x=> x._1)