¿Por qué la transmisión por chispa no funciona bien cuando uso la aplicación extendidas?
El primer código arroja una excepción de puntero nulo.
object TryBroadcast extends App{
val conf = new SparkConf().setAppName("o_o")
val sc = new SparkContext(conf)
val sample = sc.parallelize(1 to 1024)
val bro = sc.broadcast(6666)
val broSample = sample.map(x => x.toString + bro.value)
broSample.collect().foreach(println)
}
El segundo funciona bien.
object TryBroadcast {
def main(args: Array[String]) {
val conf = new SparkConf().setAppName("o_o")
val sc = new SparkContext(conf)
val sample = sc.parallelize(1 to 1024)
val bro = sc.broadcast(6666)
val broSample = sample.map(x => x.toString + bro.value)
broSample.collect().foreach(println)
}
}
Parece que la emisión de chispas tiene algo de conflicto con scala.
versión scala: 2.10.5 versión spark: 1.4.0 stackTrace:
lang.NullPointerException
at TryBroadcast$anonfun$1.apply(TryBroadcast.scala:11)
at TryBroadcast$anonfun$1.apply(TryBroadcast.scala:11)
at scala.collection.Iterator$anon$11.next(Iterator.scala:328)
at scala.collection.Iterator$class.foreach(Iterator.scala:727)
at scala.collection.AbstractIterator.foreach(Iterator.scala:1157)
at scala.collection.generic.Growable$class.$plus$plus$eq(Growable.scala:48)
at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:103)
at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:47)
at scala.collection.TraversableOnce$class.to(TraversableOnce.scala:273)
at scala.collection.AbstractIterator.to(Iterator.scala:1157)
at scala.collection.TraversableOnce$class.toBuffer(TraversableOnce.scala:265)
at scala.collection.AbstractIterator.toBuffer(Iterator.scala:1157)
at scala.collection.TraversableOnce$class.toArray(TraversableOnce.scala:252)
at scala.collection.AbstractIterator.toArray(Iterator.scala:1157)
at org.apache.spark.rdd.RDD$anonfun$collectEl segundo funciona bien.$anonfun$12.apply(RDD.scala:885)
at org.apache.spark.rdd.RDD$anonfun$collectEl segundo funciona bien.$anonfun$12.apply(RDD.scala:885)
at org.apache.spark.SparkContext$anonfun$runJob$5.apply(SparkContext.scala:1765)
at org.apache.spark.SparkContext$anonfun$runJob$5.apply(SparkContext.scala:1765)
at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:63)
at org.apache.spark.scheduler.Task.run(Task.scala:70)
at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:213)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)