Daniel Fry created SPARK-2408:
---------------------------------
Summary: RDD.map(func) dependencies issue after checkpoint & count
Key: SPARK-2408
URL: https://issues.apache.org/jira/browse/SPARK-2408
Project: Spark
Issue Type: Bug
Components: Spark Core
Affects Versions: 1.0.0, 0.9.1
Reporter: Daniel Fry
i am noticing strange behavior with a simple example use of rdd.checkpoint().
you can paste the following code into any spark-shell (e.g. with
MASTER=local[*])
// build an array of 100 random lowercase strings of length 10
val r = new scala.util.Random()
val str_arr = (1 to 100).map(a => (1 to 10).map(b => new
Character(((Math.abs(r.nextInt) % 26) + 97).toChar)).mkString(""))
// make this into an rdd
val str_rdd = sc.parallelize(str_arr)
// checkpoint & count
sc.setCheckpointDir("hdfs://[namenode]:54310/path/to/some/spark_checkpoint_dir")
str_rdd.checkpoint()
str_rdd.count
// rdd.map some dummy function
def test(a : String) : String = { return a }
str_rdd.map(test).count
this results in a surprising exception!
org.apache.spark.SparkException: Job aborted due to stage failure: Task not
serializable: java.io.NotSerializableException: scala.util.Random
at
org.apache.spark.scheduler.DAGScheduler.org$apache$spark$scheduler$DAGScheduler$$failJobAndIndependentStages(DAGScheduler.scala:1033)
at
org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1017)
at
org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1015)
at
scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59)
at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:47)
at
org.apache.spark.scheduler.DAGScheduler.abortStage(DAGScheduler.scala:1015)
at
org.apache.spark.scheduler.DAGScheduler.org$apache$spark$scheduler$DAGScheduler$$submitMissingTasks(DAGScheduler.scala:770)
at
org.apache.spark.scheduler.DAGScheduler.org$apache$spark$scheduler$DAGScheduler$$submitStage(DAGScheduler.scala:713)
at
org.apache.spark.scheduler.DAGScheduler.handleJobSubmitted(DAGScheduler.scala:697)
at
org.apache.spark.scheduler.DAGSchedulerEventProcessActor$$anonfun$receive$2.applyOrElse(DAGScheduler.scala:1176)
at akka.actor.ActorCell.receiveMessage(ActorCell.scala:498)
at akka.actor.ActorCell.invoke(ActorCell.scala:456)
at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:237)
at akka.dispatch.Mailbox.run(Mailbox.scala:219)
at
akka.dispatch.ForkJoinExecutorConfigurator$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)
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