It's not allowed to use RDD in map function.
RDD can only operated at driver of spark program.
At your case, group RDD can't be found at every executor.
I guess you want to implement subquery like operation, try to use
RDD.intersection() or join()
2014-08-29 12:43 GMT+08:00 Gary Zhao garyz...@gmail.com:
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)
