[HIVE-8545] Exception when casting Text to BytesWritable [Spark Branch]

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.1.0
• Component/s: Spark
• Assignee: Chao Sun
• Reporter: Chao Sun
• Created: 21/Oct/14 21:01
• Updated: 29/May/15 02:31
• Resolved: 23/Oct/14 19:25

Description

With the current multi-insertion implementation, when caching is enabled for input RDD, query may fail with the following exception:

2014-10-21 13:57:34,742 WARN  [task-result-getter-0]: scheduler.TaskSetManager (Logging.scala:logWarning(71)) - Lost task 0.0 in stage 1.0 (TID 1, localhost): java.lang.ClassCastException: org.apache.hadoop.io.Text cannot be cast to org.apache.hadoop.io.BytesWritable
        org.apache.hadoop.hive.ql.exec.spark.MapInput$CopyFunction.call(MapInput.java:67)
        org.apache.hadoop.hive.ql.exec.spark.MapInput$CopyFunction.call(MapInput.java:61)
        org.apache.spark.api.java.JavaPairRDD$$anonfun$pairFunToScalaFun$1.apply(JavaPairRDD.scala:1002)
        org.apache.spark.api.java.JavaPairRDD$$anonfun$pairFunToScalaFun$1.apply(JavaPairRDD.scala:1002)
        scala.collection.Iterator$$anon$11.next(Iterator.scala:328)
        org.apache.spark.storage.MemoryStore.unrollSafely(MemoryStore.scala:234)
        org.apache.spark.CacheManager.putInBlockManager(CacheManager.scala:163)
        org.apache.spark.CacheManager.getOrCompute(CacheManager.scala:70)
        org.apache.spark.rdd.RDD.iterator(RDD.scala:227)
        org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:35)
        org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:262)
        org.apache.spark.rdd.RDD.iterator(RDD.scala:229)
        org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:68)
        org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:41)
        org.apache.spark.scheduler.Task.run(Task.scala:56)
        org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:181)
        java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
        java.lang.Thread.run(Thread.java:745)

The fix should be easy. However, interestingly, this error doesn't show up when the caching is turned off. We need to find out why.

Issue Links

• Is contained by: HIVE-7292 Hive on Spark
• is depended upon by: HIVE-8437 Modify SparkPlan generation to set toCache flag to SparkTrans where caching is needed [Spark Branch]
• relates to: HIVE-8578 Investigate test failures related to HIVE-8545 [Spark Branch]
• links to: RB Link