我把累加器写在main方法中,就可以完美的算出答案,但是,我实现App特质时,每次运行的结果都不一样,是为什么呢?
import org.apache.spark.{SparkConf, SparkContext}
object AccumulatorDemo extends App{
val conf = new SparkConf().setAppName("AccumulatorDemo").setMaster("local
- "
- )
val sc = new SparkContext(conf)
val sum = sc.accumulator(0)
val numbers = sc.parallelize(Array(1,2,3,4,5,6),2)
numbers.foreach(num => sum+=num)
println(sum)
sc.stop()
}