Hi, I've been encountering a NPE invoking reduceByKey on JavaPairRDD since upgrading to 1.0.0 . The issue is straightforward to reproduce with 1.0.0 and doesn't occur with 0.9.0. The stack trace is as follows:
14/06/26 21:05:35 WARN scheduler.TaskSetManager: Loss was due to java.lang.NullPointerException java.lang.NullPointerException at org.apache.spark.api.java.JavaPairRDD$$anonfun$pairFunToScalaFun$1.apply(JavaPairRDD.scala:750) at org.apache.spark.api.java.JavaPairRDD$$anonfun$pairFunToScalaFun$1.apply(JavaPairRDD.scala:750) at scala.collection.Iterator$$anon$11.next(Iterator.scala:328) at org.apache.spark.Aggregator.combineValuesByKey(Aggregator.scala:59) at org.apache.spark.rdd.PairRDDFunctions$$anonfun$1.apply(PairRDDFunctions.scala:96) at org.apache.spark.rdd.PairRDDFunctions$$anonfun$1.apply(PairRDDFunctions.scala:95) at org.apache.spark.rdd.RDD$$anonfun$14.apply(RDD.scala:582) at org.apache.spark.rdd.RDD$$anonfun$14.apply(RDD.scala:582) at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:35) at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:262) at org.apache.spark.rdd.RDD.iterator(RDD.scala:229) at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:158) at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:99) at org.apache.spark.scheduler.Task.run(Task.scala:51) at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:187) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603) at java.lang.Thread.run(Thread.java:722) I've raised a bug to track this issue : https://issues.apache.org/jira/browse/SPARK-2292 Thanks, Bharath
