Spark Stack Überlauf Fehler bei der Verwendung von sc.union

Question

Ich benutze Spark Scala API und versuchen, 3000 RDDs Union.

Ich mache eine For-Schleife, die über 3000 Textdateien iteriert, eine RDD erstellt und eine Vereinigung aus der alten RDD und der neuen RDD macht, die gerade aus der Textdatei erstellt wurde.

Hier ist mein Code:

var tempRDD = sc.textFile(s"" + fileNameArray(ind)).filter(_.split(",",-1).length == cols).filter(line => line.split(",").filter(cell => cell.length > 0).length == cols). 
    map{line => 
     val parts = line.split(",",-1); 
     val relaventFeatures = Array(parts(ind0),parts(ind1),parts(ind2)); 
     val vector = Vectors.dense(relaventFeatures.map(_.toDouble)); 
     val fileName = fileNameArray(ind); 
     (fileName, (parts(0), vector))}; 
    if (!tempRDD.isEmpty){ 
     allRDD = sc.union(allRDD, tempRDD); 
    } 

ich eine question sah, die über immer einen Stapel overfow gefragt, wann RDD.union verwenden und die Antwort gesagt, dass, wenn Sie SparkContext.union ein Stapelüberlauf verwenden kann nicht passieren - aber ich bekomme eins:

java.lang.StackOverflowError at org.apache.spark.rdd.UnionRDD$$anonfun$1.apply(UnionRDD.scala:66) at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) at scala.collection.immutable.List.foreach(List.scala:318) at scala.collection.TraversableLike$class.map(TraversableLike.scala:244) at scala.collection.AbstractTraversable.map(Traversable.scala:105) at org.apache.spark.rdd.UnionRDD.getPartitions(UnionRDD.scala:66) at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:239) at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:237) at scala.Option.getOrElse(Option.scala:120) at org.apache.spark.rdd.RDD.partitions(RDD.scala:237) at org.apache.spark.rdd.UnionRDD$$anonfun$1.apply(UnionRDD.scala:66) at org.apache.spark.rdd.UnionRDD$$anonfun$1.apply(UnionRDD.scala:66) at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) at scala.collection.immutable.List.foreach(List.scala:318) at scala.collection.TraversableLike$class.map(TraversableLike.scala:244) at scala.collection.AbstractTraversable.map(Traversable.scala:105) at org.apache.spark.rdd.UnionRDD.getPartitions(UnionRDD.scala:66) at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:239) at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:237) at scala.Option.getOrElse(Option.scala:120) at org.apache.spark.rdd.RDD.partitions(RDD.scala:237) at org.apache.spark.rdd.UnionRDD$$anonfun$1.apply(UnionRDD.scala:66) at org.apache.spark.rdd.UnionRDD$$anonfun$1.apply(UnionRDD.scala:66) at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) at scala.collection.immutable.List.foreach(List.scala:318) at scala.collection.TraversableLike$class.map(TraversableLike.scala:244) at scala.collection.AbstractTraversable.map(Traversable.scala:105) at org.apache.spark.rdd.UnionRDD.getPartitions(UnionRDD.scala:66) at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:239) at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:237) at scala.Option.getOrElse(Option.scala:120) at org.apache.spark.rdd.RDD.partitions(RDD.scala:237) at org.apache.spark.rdd.UnionRDD$$anonfun$1.apply(UnionRDD.scala:66) at org.apache.spark.rdd.UnionRDD$$anonfun$1.apply(UnionRDD.scala:66) at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) at scala.collection.immutable.List.foreach(List.scala:318) at scala.collection.TraversableLike$class.map(TraversableLike.scala:244) at scala.collection.AbstractTraversable.map(Traversable.scala:105) at org.apache.spark.rdd.UnionRDD.getPartitions(UnionRDD.scala:66) at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:239) at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:237) at scala.Option.getOrElse(Option.scala:120) at org.apache.spark.rdd.RDD.partitions(RDD.scala:237) at org.apache.spark.rdd.UnionRDD$$anonfun$1.apply(UnionRDD.scala:66) at org.apache.spark.rdd.UnionRDD$$anonfun$1.apply(UnionRDD.scala:66) at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) at scala.collection.immutable.List.foreach(List.scala:318) at scala.collection.TraversableLike$class.map(TraversableLike.scala:244) at scala.collection.AbstractTraversable.map(Traversable.scala:105) at org.apache.spark.rdd.UnionRDD.getPartitions(UnionRDD.scala:66) at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:239) at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:237) at scala.Option.getOrElse(Option.scala:120) at org.apache.spark.rdd.RDD.partitions(RDD.scala:237) at org.apache.spark.rdd.UnionRDD$$anonfun$1.apply(UnionRDD.scala:66) at org.apache.spark.rdd.UnionRDD$$anonfun$1.apply(UnionRDD.scala:66) at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) at scala.collection.immutable.List.foreach(List.scala:318) at scala.collection.TraversableLike$class.map(TraversableLike.scala:244) at scala.collection.AbstractTraversable.map(Traversable.scala:105) at org.apache.spark.rdd.UnionRDD.getPartitions(UnionRDD.scala:66) at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:239) at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:237) at scala.Option.getOrElse(Option.scala:120) at org.apache.spark.rdd.RDD.partitions(RDD.scala:237) at org.apache.spark.rdd.UnionRDD$$anonfun$1.apply(UnionRDD.scala:66) at org.apache.spark.rdd.UnionRDD$$anonfun$1.apply(UnionRDD.scala:66) at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) at scala.collection.immutable.List.foreach(List.scala:318) at scala.collection.TraversableLike$class.map(TraversableLike.scala:244) at scala.collection.AbstractTraversable.map(Traversable.scala:105) at org.apache.spark.rdd.UnionRDD.getPartitions(UnionRDD.scala:66) at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:239) at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:237) at scala.Option.getOrElse(Option.scala:120) at org.apache.spark.rdd.RDD.partitions(RDD.scala:237) at org.apache.spark.rdd.UnionRDD$$anonfun$1.apply(UnionRDD.scala:66) at org.apache.spark.rdd.UnionRDD$$anonfun$1.apply(UnionRDD.scala:66) at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) at scala.collection.immutable.List.foreach(List.scala:318) at scala.collection.TraversableLike$class.map(TraversableLike.scala:244) at scala.collection.AbstractTraversable.map(Traversable.scala:105) at org.apache.spark.rdd.UnionRDD.getPartitions(UnionRDD.scala:66) at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:239) at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:237) at scala.Option.getOrElse(Option.scala:120) at org.apache.spark.rdd.RDD.partitions(RDD.scala:237) at org.apache.spark.rdd.UnionRDD$$anonfun$1.apply(UnionRDD.scala:66) at org.apache.spark.rdd.UnionRDD$$anonfun$1.apply(UnionRDD.scala:66) at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) at scala.collection.immutable.List.foreach(List.scala:318) at scala.collection.TraversableLike$class.map(TraversableLike.scala:244) at scala.collection.AbstractTraversable.map(Traversable.scala:105) at org.apache.spark.rdd.UnionRDD.getPartitions(UnionRDD.scala:66) at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:239) at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:237) at scala.Option.getOrElse(Option.scala:120) at org.apache.spark.rdd.RDD.partitions(RDD.scala:237) at org.apache.spark.rdd.UnionRDD$$anonfun$1.apply(UnionRDD.scala:66) at org.apache.spark.rdd.UnionRDD$$anonfun$1.apply(UnionRDD.scala:66) at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) at scala.collection.immutable.List.foreach(List.scala:318) at scala.collection.TraversableLike$class.map(TraversableLike.scala:244) at scala.collection.AbstractTraversable.map(Traversable.scala:105) at org.apache.spark.rdd.UnionRDD.getPartitions(UnionRDD.scala:66) at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:239) at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:237) at scala.Option.getOrElse(Option.scala:120) at org.apache.spark.rdd.RDD.partitions(RDD.scala:237) at org.apache.spark.rdd.UnionRDD$$anonfun$1.apply(UnionRDD.scala:66) at org.apache.spark.rdd.UnionRDD$$anonfun$1.apply(UnionRDD.scala:66) at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) at scala.collection.immutable.List.foreach(List.scala:318) at scala.collection.TraversableLike$class.map(TraversableLike.scala:244) at scala.collection.AbstractTraversable.map(Traversable.scala:105) at org.apache.spark.rdd.UnionRDD.getPartitions(UnionRDD.scala:66) at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:239) at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:237) at scala.Option.getOrElse(Option.scala:120) at org.apache.spark.rdd.RDD.partitions(RDD.scala:237) at org.apache.spark.rdd.UnionRDD$$anonfun$1.apply(UnionRDD.scala:66) at org.apache.spark.rdd.UnionRDD$$anonfun$1.apply(UnionRDD.scala:66) at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) at scala.collection.immutable.List.foreach(List.scala:318) at scala.collection.TraversableLike$class.map(TraversableLike.scala:244) at scala.collection.AbstractTraversable.map(Traversable.scala:105) at org.apache.spark.rdd.UnionRDD.getPartitions(UnionRDD.scala:66) at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:239) at org.apache.spark.rdd.RDD$$anonfun$partitions$2.apply(RDD.scala:237) at scala.Option.getOrElse(Option.scala:120) 

Wer weiß, was ich falsch mache?

Answer 1

Zunächst einmal. Es scheint, als ob Ihr allRdd ein var ist. Versuche das zu vermeiden; Sie können etwas tun wie:

val allRdd = fileNameArray.map(name => { 
    val rdd = sc.textFile(s"" + name).filter(...) 
}).reduce(_ + _) 

Jetzt ... Beitritt 3000 RDDs klingt ein bisschen verrückt. Union Verfahren macht dies:

new UnionRDD(sc, Array(this, other)) 

Wenn Sie eine von 3000 RDDs machen verbinden Sie erhalten:

new UnionRDD(sc, Array(this, new UnionRDD(sc, Array(this2, new UnionRDD(sc, Array(this3, new UnionRDD(sc, Array(this4, (........))))))))) 

Das ist der Grund Ihrer Stackoverflow

Sie können Platzhalter verwenden und sie lesen aus einem Verzeichnis ...

val allRdds = sc.textFile("filesDir/*.txt"). // or whatever 
filter(...) 

Oder wenn Sie die Liste der Dateien lesen:

val allRdds = sc.textFile(fileNameArray.mkString(",")).filter(...) 

Update:

Da Sie den Dateinamen benötigen, können Sie wholeTextFiles Funktion:

val files: RDD[(String, String)] = sc.wholeTextFiles(fileNameArray.mkString(",")). 
    flatMap(f => f._2.split("\n").map(l => (f._1, l))) 
files.filter(...).mapValues(...)