[SPARK-32436] Initialize numNonEmptyBlocks in HighlyCompressedMapStatus.readExternal

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.1.0
• Fix Version/s: 3.0.2, 3.1.0
• Component/s: Spark Core
• Assignee: Dongjoon Hyun
• Reporter: Dongjoon Hyun
• Created: 25/Jul/20 07:13
• Updated: 16/Oct/20 21:06
• Resolved: 25/Jul/20 17:16

Description

In Scala 2.13, this causes several UT failures because `HighlyCompressedMapStatus.readExternal` doesn't initialize this field. The following two are the examples.

• org.apache.spark.rdd.RDDSuite

    Cause: java.lang.NoSuchFieldError: numNonEmptyBlocks
    at org.apache.spark.scheduler.HighlyCompressedMapStatus.<init>(MapStatus.scala:181)
    at org.apache.spark.scheduler.HighlyCompressedMapStatus$.apply(MapStatus.scala:280)
    at org.apache.spark.scheduler.MapStatus$.apply(MapStatus.scala:73)
    at org.apache.spark.shuffle.sort.UnsafeShuffleWriter.closeAndWriteOutput(UnsafeShuffleWriter.java:231)
    at org.apache.spark.shuffle.sort.UnsafeShuffleWriter.write(UnsafeShuffleWriter.java:179)
    at org.apache.spark.shuffle.ShuffleWriteProcessor.write(ShuffleWriteProcessor.scala:59)
    at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:99)
    at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:52)
    at org.apache.spark.scheduler.Task.run(Task.scala:127)
    at org.apache.spark.executor.Executor$TaskRunner.$anonfun$run$3(Executor.scala:464)
  

• org.apache.spark.scheduler.MapStatusSuite

  *** RUN ABORTED ***
    java.lang.NoSuchFieldError: numNonEmptyBlocks
    at org.apache.spark.scheduler.HighlyCompressedMapStatus.<init>(MapStatus.scala:181)
    at org.apache.spark.scheduler.HighlyCompressedMapStatus$.apply(MapStatus.scala:280)
  

Issue Links

• links to: [Github] Pull Request #29230 (dongjoon-hyun)
• links to: [Github] Pull Request #29231 (dongjoon-hyun)