I'm new to Spark. When I use the Movie Lens dataset 100k (http://grouplens.org/datasets/movielens/), Spark crashes when I run the following code. The first call to movieData.first() gives the correct result. Depending on which machine I use, it crashed the second or third time. Does anybody know why? When I use scala in the Spark shell, this does not happen. Scala gives the correct result every time.
import sys sys.path.append("d:/spark/python") sys.path.append("d:/spark/python/lib/py4j-0.8.2.1-src.zip") from pyspark import SparkContext import numpy import os os.environ["SPARK_HOME"] = "d:/spark" sc = SparkContext(appName="testapp") movieData = sc.textFile("d:/moviedata/u.data") movieData.first() movieData.first() movieData.first() Py4JJavaError: An error occurred while calling z:org.apache.spark.api.python.PythonRDD.runJob. : org.apache.spark.SparkException: Job aborted due to stage failure: Task 0 in stage 2.0 failed 1 times, most recent failure: Lost task 0.0 in stage 2.0 (TID 2, localhost): java.net.SocketException: Connection reset by peer: socket write error at java.net.SocketOutputStream.socketWrite0(Native Method) at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:113) at java.net.SocketOutputStream.write(SocketOutputStream.java:159) at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82) at java.io.BufferedOutputStream.write(BufferedOutputStream.java:126) at java.io.DataOutputStream.write(DataOutputStream.java:107) at java.io.FilterOutputStream.write(FilterOutputStream.java:97) at org.apache.spark.api.python.PythonRDD$.writeUTF(PythonRDD.scala:592) at org.apache.spark.api.python.PythonRDD$$anonfun$writeIteratorToStream$2.apply(PythonRDD.scala:389) at org.apache.spark.api.python.PythonRDD$$anonfun$writeIteratorToStream$2.apply(PythonRDD.scala:388) at scala.collection.Iterator$class.foreach(Iterator.scala:727) at scala.collection.AbstractIterator.foreach(Iterator.scala:1157) at org.apache.spark.api.python.PythonRDD$.writeIteratorToStream(PythonRDD.scala:388) at org.apache.spark.api.python.PythonRDD$WriterThread$$anonfun$run$1.apply$mcV$sp(PythonRDD.scala:242) at org.apache.spark.api.python.PythonRDD$WriterThread$$anonfun$run$1.apply(PythonRDD.scala:204) at org.apache.spark.api.python.PythonRDD$WriterThread$$anonfun$run$1.apply(PythonRDD.scala:204) at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1460) at org.apache.spark.api.python.PythonRDD$WriterThread.run(PythonRDD.scala:203) Driver stacktrace: at org.apache.spark.scheduler.DAGScheduler.org$apache$spark$scheduler$DAGScheduler$$failJobAndIndependentStages(DAGScheduler.scala:1214) at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1203) at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1202) at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59) at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:47) at org.apache.spark.scheduler.DAGScheduler.abortStage(DAGScheduler.scala:1202) at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:696) at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:696) at scala.Option.foreach(Option.scala:236) at org.apache.spark.scheduler.DAGScheduler.handleTaskSetFailed(DAGScheduler.scala:696) at org.apache.spark.scheduler.DAGSchedulerEventProcessActor$$anonfun$receive$2.applyOrElse(DAGScheduler.scala:1420) at akka.actor.Actor$class.aroundReceive(Actor.scala:465) at org.apache.spark.scheduler.DAGSchedulerEventProcessActor.aroundReceive(DAGScheduler.scala:1375) at akka.actor.ActorCell.receiveMessage(ActorCell.scala:516) at akka.actor.ActorCell.invoke(ActorCell.scala:487) at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:238) at akka.dispatch.Mailbox.run(Mailbox.scala:220) at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(AbstractDispatcher.scala:393) at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260) at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339) at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979) at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)