Is your file managed by Hive (and thus present in a Hive metastore)? In that
case, Spark SQL
(https://spark.apache.org/docs/latest/sql-programming-guide.html) is the
easiest way.
Matei
On September 23, 2014 at 2:26:10 PM, Pramod Biligiri (pramodbilig...@gmail.com)
wrote:
Hi,
I'm trying to read some data in RCFiles using Spark, but can't seem to find a
suitable example anywhere. Currently I've written the following bit of code
that lets me count() the no. of records, but when I try to do a collect() or a
map(), it fails with a ConcurrentModificationException. I'm running Spark 1.0.1
on a Hadoop YARN cluster:
import org.apache.hadoop.hive.ql.io.RCFileInputFormat;
val file = sc.hadoopFile("/hdfs/path/to/file",
classOf[org.apache.hadoop.hive.ql.io.RCFileInputFormat[org.apache.hadoop.io.LongWritable,org.apache.hadoop.hive.serde2.columnar.BytesRefArrayWritable]],
classOf[org.apache.hadoop.io.LongWritable],
classOf[org.apache.hadoop.hive.serde2.columnar.BytesRefArrayWritable]
)
file.collect()
org.apache.spark.SparkException: Job aborted due to stage failure: Task 10.0:6
failed 4 times, most recent failure: Exception failure in TID 395 on host
(redacted): com.esotericsoftware.kryo.KryoException:
java.util.ConcurrentModificationException
Serialization trace:
classes (sun.misc.Launcher$AppClassLoader)
parent (org.apache.spark.repl.ExecutorClassLoader)
classLoader (org.apache.hadoop.mapred.JobConf)
conf (org.apache.hadoop.io.compress.GzipCodec)
codec (org.apache.hadoop.hive.ql.io.RCFile$ValueBuffer)
this$0
(org.apache.hadoop.hive.ql.io.RCFile$ValueBuffer$LazyDecompressionCallbackImpl)
lazyDecompressObj (org.apache.hadoop.hive.serde2.columnar.BytesRefWritable)
bytesRefWritables (org.apache.hadoop.hive.serde2.columnar.BytesRefArrayWritable)
com.esotericsoftware.kryo.serializers.FieldSerializer$ObjectField.write(FieldSerializer.java:585)
com.esotericsoftware.kryo.serializers.FieldSerializer.write(FieldSerializer.java:213)
com.esotericsoftware.kryo.Kryo.writeObject(Kryo.java:501)
com.esotericsoftware.kryo.serializers.FieldSerializer$ObjectField.write(FieldSerializer.java:564)
com.esotericsoftware.kryo.serializers.FieldSerializer.write(FieldSerializer.java:213)
com.esotericsoftware.kryo.Kryo.writeObject(Kryo.java:501)
com.esotericsoftware.kryo.serializers.FieldSerializer$ObjectField.write(FieldSerializer.java:564)
com.esotericsoftware.kryo.serializers.FieldSerializer.write(FieldSerializer.java:213)
com.esotericsoftware.kryo.Kryo.writeObject(Kryo.java:501)
com.esotericsoftware.kryo.serializers.FieldSerializer$ObjectField.write(FieldSerializer.java:564)
com.esotericsoftware.kryo.serializers.FieldSerializer.write(FieldSerializer.java:213)
com.esotericsoftware.kryo.Kryo.writeObject(Kryo.java:501)
com.esotericsoftware.kryo.serializers.FieldSerializer$ObjectField.write(FieldSerializer.java:564)
com.esotericsoftware.kryo.serializers.FieldSerializer.write(FieldSerializer.java:213)
com.esotericsoftware.kryo.Kryo.writeObject(Kryo.java:501)
com.esotericsoftware.kryo.serializers.FieldSerializer$ObjectField.write(FieldSerializer.java:564)
com.esotericsoftware.kryo.serializers.FieldSerializer.write(FieldSerializer.java:213)
com.esotericsoftware.kryo.Kryo.writeObject(Kryo.java:501)
com.esotericsoftware.kryo.serializers.FieldSerializer$ObjectField.write(FieldSerializer.java:564)
com.esotericsoftware.kryo.serializers.FieldSerializer.write(FieldSerializer.java:213)
com.esotericsoftware.kryo.Kryo.writeClassAndObject(Kryo.java:568)
com.esotericsoftware.kryo.serializers.DefaultArraySerializers$ObjectArraySerializer.write(DefaultArraySerializers.java:318)
com.esotericsoftware.kryo.serializers.DefaultArraySerializers$ObjectArraySerializer.write(DefaultArraySerializers.java:293)
com.esotericsoftware.kryo.Kryo.writeObject(Kryo.java:501)
com.esotericsoftware.kryo.serializers.FieldSerializer$ObjectField.write(FieldSerializer.java:564)
com.esotericsoftware.kryo.serializers.FieldSerializer.write(FieldSerializer.java:213)
com.esotericsoftware.kryo.Kryo.writeClassAndObject(Kryo.java:568)
com.twitter.chill.Tuple2Serializer.write(TupleSerializers.scala:38)
com.twitter.chill.Tuple2Serializer.write(TupleSerializers.scala:34)
com.esotericsoftware.kryo.Kryo.writeClassAndObject(Kryo.java:568)
com.esotericsoftware.kryo.serializers.DefaultArraySerializers$ObjectArraySerializer.write(DefaultArraySerializers.java:318)
com.esotericsoftware.kryo.serializers.DefaultArraySerializers$ObjectArraySerializer.write(DefaultArraySerializers.java:293)
com.esotericsoftware.kryo.Kryo.writeClassAndObject(Kryo.java:568)
org.apache.spark.serializer.KryoSerializerInstance.serialize(KryoSerializer.scala:141)
org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:193)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
java.lang.Thread.run(Thread.java:722)
Driver stacktrace:
at
org.apache.spark.scheduler.DAGScheduler.org$apache$spark$scheduler$DAGScheduler$$failJobAndIndependentStages(DAGScheduler.scala:1046)
at
org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1030)
at
org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1028)
at
scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59)
at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:47)
at org.apache.spark.scheduler.DAGScheduler.abortStage(DAGScheduler.scala:1028)
at
org.apache.spark.scheduler.DAGScheduler$$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$2.applyOrElse(DAGScheduler.scala:1231)
at akka.actor.ActorCell.receiveMessage(ActorCell.scala:498)
at akka.actor.ActorCell.invoke(ActorCell.scala:456)
at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:237)
at akka.dispatch.Mailbox.run(Mailbox.scala:219)
at
akka.dispatch.ForkJoinExecutorConfigurator$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)
Pramod
