[SPARK-2442] Add a Hadoop Writable serializer

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Duplicate
• Assignee: Unassigned
• Reporter: Hari Shreedharan
• Created: 11/Jul/14 00:10
• Updated: 24/Jan/15 13:05
• Resolved: 24/Jan/15 13:05

Description

Using data read from hadoop files in shuffles can cause exceptions with the following stacktrace:

java.io.NotSerializableException: org.apache.hadoop.io.BytesWritable
	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1181)
	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1541)
	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1506)
	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1429)
	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1175)
	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:347)
	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:42)
	at org.apache.spark.storage.DiskBlockObjectWriter.write(BlockObjectWriter.scala:179)
	at org.apache.spark.scheduler.ShuffleMapTask$$anonfun$runTask$1.apply(ShuffleMapTask.scala:161)
	at org.apache.spark.scheduler.ShuffleMapTask$$anonfun$runTask$1.apply(ShuffleMapTask.scala:158)
	at scala.collection.Iterator$class.foreach(Iterator.scala:727)
	at scala.collection.AbstractIterator.foreach(Iterator.scala:1157)
	at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:158)
	at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:99)
	at org.apache.spark.scheduler.Task.run(Task.scala:51)
	at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:183)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1146)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:679)

This though seems to go away if Kyro serializer is used. I am wondering if adding a Hadoop-writables friendly serializer makes sense as it is likely to perform better than Kyro without registration, since Writables don't implement Serializable - so the serialization might not be the most efficient.

Issue Links

• duplicates: SPARK-2421 Spark should treat writable as serializable for keys