[SPARK-17975] EMLDAOptimizer fails with ClassCastException on YARN

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.1
• Fix Version/s: 2.0.3, 2.1.1, 2.2.0
• Component/s: MLlib

Environment

Centos 6, CDH 5.7, Java 1.7u80

• Assignee: Tathagata Das
• Reporter: Jeff Stein
• Created: 17/Oct/16 19:49
• Updated: 09/Feb/17 18:53
• Resolved: 09/Feb/17 18:53

Description

I'm able to reproduce the error consistently with a 2000 record text file with each record having 1-5 terms and checkpointing enabled. It looks like the problem was introduced with the resolution for SPARK-13355.

The EdgeRDD class seems to be lying about it's type in a way that causes RDD.mapPartitionsWithIndex method to be unusable when it's referenced as an RDD of Edge elements.

val spark = SparkSession.builder.appName("lda").getOrCreate()
spark.sparkContext.setCheckpointDir("hdfs:///tmp/checkpoints")
val data: RDD[(Long, Vector)] = // snip
data.setName("data").cache()
val lda = new LDA
val optimizer = new EMLDAOptimizer
lda.setOptimizer(optimizer)
  .setK(10)
  .setMaxIterations(400)
  .setAlpha(-1)
  .setBeta(-1)
  .setCheckpointInterval(7)
val ldaModel = lda.run(data)

16/10/16 23:53:54 WARN TaskSetManager: Lost task 3.0 in stage 348.0 (TID 1225, server2.domain): java.lang.ClassCastException: scala.Tuple2 cannot be cast to org.apache.spark.graphx.Edge
	at org.apache.spark.graphx.EdgeRDD$$anonfun$1$$anonfun$apply$1.apply(EdgeRDD.scala:107)
	at scala.collection.Iterator$class.foreach(Iterator.scala:893)
	at org.apache.spark.InterruptibleIterator.foreach(InterruptibleIterator.scala:28)
	at org.apache.spark.graphx.EdgeRDD$$anonfun$1.apply(EdgeRDD.scala:107)
	at org.apache.spark.graphx.EdgeRDD$$anonfun$1.apply(EdgeRDD.scala:105)
	at org.apache.spark.rdd.RDD$$anonfun$mapPartitionsWithIndex$1$$anonfun$apply$25.apply(RDD.scala:820)
	at org.apache.spark.rdd.RDD$$anonfun$mapPartitionsWithIndex$1$$anonfun$apply$25.apply(RDD.scala:820)
	at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:38)
	at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:319)
	at org.apache.spark.rdd.RDD.iterator(RDD.scala:283)
	at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:38)
	at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:319)
	at org.apache.spark.rdd.RDD$$anonfun$8.apply(RDD.scala:332)
	at org.apache.spark.rdd.RDD$$anonfun$8.apply(RDD.scala:330)
	at org.apache.spark.storage.BlockManager$$anonfun$doPutIterator$1.apply(BlockManager.scala:935)
	at org.apache.spark.storage.BlockManager$$anonfun$doPutIterator$1.apply(BlockManager.scala:926)
	at org.apache.spark.storage.BlockManager.doPut(BlockManager.scala:866)
	at org.apache.spark.storage.BlockManager.doPutIterator(BlockManager.scala:926)
	at org.apache.spark.storage.BlockManager.getOrElseUpdate(BlockManager.scala:670)
	at org.apache.spark.rdd.RDD.getOrCompute(RDD.scala:330)
	at org.apache.spark.rdd.RDD.iterator(RDD.scala:281)
	at org.apache.spark.graphx.EdgeRDD.compute(EdgeRDD.scala:50)
	at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:319)
	at org.apache.spark.rdd.RDD.iterator(RDD.scala:283)
	at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:38)
	at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:319)
	at org.apache.spark.rdd.RDD.iterator(RDD.scala:283)
	at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:38)
	at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:319)
	at org.apache.spark.rdd.RDD.iterator(RDD.scala:283)
	at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:79)
	at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:47)
	at org.apache.spark.scheduler.Task.run(Task.scala:86)
	at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:274)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:722)

Issue Links

• Is contained by: SPARK-14804 Graph vertexRDD/EdgeRDD checkpoint results ClassCastException:
• is related to: SPARK-17265 EdgeRDD Difference throws an exception
• relates to: SPARK-14804 Graph vertexRDD/EdgeRDD checkpoint results ClassCastException:
• links to: [Github] Pull Request #16494 (imatiach-msft)