Hello I'm new to Spark and playing around, but saw the following error. Could anyone to help on it?
Thanks Gary scala> c res15: org.apache.spark.rdd.RDD[String] = FlatMappedRDD[7] at flatMap at <console>:23 scala> group res16: org.apache.spark.rdd.RDD[(String, Iterable[String])] = MappedValuesRDD[5] at groupByKey at <console>:19 val d = c.map(i=>group.filter(_._1 ==i )) d.first 14/08/29 04:39:33 INFO TaskSchedulerImpl: Cancelling stage 28 14/08/29 04:39:33 INFO DAGScheduler: Failed to run first at <console>:28 org.apache.spark.SparkException: Job aborted due to stage failure: Task 28.0:180 failed 4 times, most recent failure: Exception failure in TID 3605 on host mcs-spark-slave1-staging.snc1: java.lang.NullPointerException org.apache.spark.rdd.RDD.filter(RDD.scala:282) $iwC$$iwC$$iwC$$iwC$$iwC$$iwC$$anonfun$1.apply(<console>:25) $iwC$$iwC$$iwC$$iwC$$iwC$$iwC$$anonfun$1.apply(<console>:25) scala.collection.Iterator$$anon$11.next(Iterator.scala:328) scala.collection.Iterator$$anon$10.next(Iterator.scala:312) scala.collection.Iterator$class.foreach(Iterator.scala:727) scala.collection.AbstractIterator.foreach(Iterator.scala:1157) scala.collection.generic.Growable$class.$plus$plus$eq(Growable.scala:48) scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:103) scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:47) scala.collection.TraversableOnce$class.to(TraversableOnce.scala:273) scala.collection.AbstractIterator.to(Iterator.scala:1157) scala.collection.TraversableOnce$class.toBuffer(TraversableOnce.scala:265) scala.collection.AbstractIterator.toBuffer(Iterator.scala:1157) scala.collection.TraversableOnce$class.toArray(TraversableOnce.scala:252) scala.collection.AbstractIterator.toArray(Iterator.scala:1157) org.apache.spark.rdd.RDD$$anonfun$28.apply(RDD.scala:1003) org.apache.spark.rdd.RDD$$anonfun$28.apply(RDD.scala:1003) org.apache.spark.SparkContext$$anonfun$runJob$4.apply(SparkContext.scala:1083) org.apache.spark.SparkContext$$anonfun$runJob$4.apply(SparkContext.scala:1083) org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:111) org.apache.spark.scheduler.Task.run(Task.scala:51) org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:183) java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) java.lang.Thread.run(Thread.java:744) Driver stacktrace: at org.apache.spark.scheduler.DAGScheduler.org $apache$spark$scheduler$DAGScheduler$$failJobAndIndependentStages(DAGScheduler.scala:1049) at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1033) at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1031) at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59) at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:47) at org.apache.spark.scheduler.DAGScheduler.abortStage(DAGScheduler.scala:1031) at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:635) at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:635) at scala.Option.foreach(Option.scala:236) at org.apache.spark.scheduler.DAGScheduler.handleTaskSetFailed(DAGScheduler.scala:635) at org.apache.spark.scheduler.DAGSchedulerEventProcessActor$$anonfun$receive$2.applyOrElse(DAGScheduler.scala:1234) at akka.actor.ActorCell.receiveMessage(ActorCell.scala:498) at akka.actor.ActorCell.invoke(ActorCell.scala:456) at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:237) at akka.dispatch.Mailbox.run(Mailbox.scala:219) at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(AbstractDispatcher.scala:386) 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)