Hi,
Disclaimer : Newbie (well, a returning user)
Setup :
20 nodes
-Dspark.executor.memory=40g , essentially tons of space for my usecase
Pretty straight forward join between two inputs
- 17G (distributed in 10 equally sized - 1.7g files)
- 49Mb (1 file)
I just need to join based on the keys and write out values from both as tuples
==================================================================
val XA = sc.textFile("path-to-17GB") //assume this to be a tab separated
key value pair
val XAMap = XA.map(x => {
val arr = x.split("\t")
(arr(0),arr(1))
})
val XY = sc.textFile("pathTo49MB") // assume it to be a tab separated key
value pair
val XYMap = XY.map(x => {
val arr = x.split("\t")
(arr(0), arr(1))
}).collect.toMap
val bc = sc.broadcast(XYMap)
val joined = XAMap.map(v => {
(bc.value(v._1),v._2)
})
joined.saveAsTextFile("path-to-output")
==================================================================
When i try to save the text file it throws a OOME and my shell quits.
any clues?
scala> joined.saveAsTextFile("path-to-output")
Uncaught error from thread [spark-akka.actor.default-dispatcher-4] shutting
down JVM since 'akka.jvm-exit-on-fatal-error' is enabled for ActorSystem[spark]
java.lang.OutOfMemoryError: Java heap space
at java.util.Arrays.copyOf(Arrays.java:2786)
at java.io.ByteArrayOutputStream.write(ByteArrayOutputStream.java:94)
at
java.io.ObjectOutputStream$BlockDataOutputStream.write(ObjectOutputStream.java:1823)
at java.io.ObjectOutputStream.write(ObjectOutputStream.java:670)
at
org.apache.spark.scheduler.ResultTask.writeExternal(ResultTask.scala:116)
at
java.io.ObjectOutputStream.writeExternalData(ObjectOutputStream.java:1429)
at
java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1398)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1158)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:330)
at
org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:27)
at
org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:47)
at
org.apache.spark.scheduler.Task$.serializeWithDependencies(Task.scala:78)
at
org.apache.spark.scheduler.cluster.ClusterTaskSetManager.resourceOffer(ClusterTaskSetManager.scala:375)
at
org.apache.spark.scheduler.cluster.ClusterScheduler$$anonfun$resourceOffers$3$$anonfun$apply$3$$anonfun$apply$1.apply$mcVI$sp(ClusterScheduler.scala:215)
at
org.apache.spark.scheduler.cluster.ClusterScheduler$$anonfun$resourceOffers$3$$anonfun$apply$3.apply(ClusterScheduler.scala:212)
at
org.apache.spark.scheduler.cluster.ClusterScheduler$$anonfun$resourceOffers$3$$anonfun$apply$3.apply(ClusterScheduler.scala:209)
at scala.collection.Iterator$class.foreach(Iterator.scala:772)
at scala.collection.Iterator$$anon$19.foreach(Iterator.scala:399)
at scala.collection.IterableLike$class.foreach(IterableLike.scala:73)
at scala.Enumeration$ValueSet.foreach(Enumeration.scala:234)
at
org.apache.spark.scheduler.cluster.ClusterScheduler$$anonfun$resourceOffers$3.apply(ClusterScheduler.scala:209)
at
org.apache.spark.scheduler.cluster.ClusterScheduler$$anonfun$resourceOffers$3.apply(ClusterScheduler.scala:209)
at
scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:60)
at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:47)
at
org.apache.spark.scheduler.cluster.ClusterScheduler.resourceOffers(ClusterScheduler.scala:209)
at
org.apache.spark.scheduler.cluster.StandaloneSchedulerBackend$DriverActor.makeOffers(StandaloneSchedulerBackend.scala:113)
at
org.apache.spark.scheduler.cluster.StandaloneSchedulerBackend$DriverActor$$anonfun$receive$1.apply(StandaloneSchedulerBackend.scala:91)
at
org.apache.spark.scheduler.cluster.StandaloneSchedulerBackend$DriverActor$$anonfun$receive$1.apply(StandaloneSchedulerBackend.scala:64)
at akka.actor.Actor$class.apply(Actor.scala:318)
at
org.apache.spark.scheduler.cluster.StandaloneSchedulerBackend$DriverActor.apply(StandaloneSchedulerBackend.scala:47)
at akka.actor.ActorCell.invoke(ActorCell.scala:626)
at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:197)
