Saisai Shao created SPARK-3032: ---------------------------------- Summary: Potential bug when running sort-based shuffle with sorting using TimSort Key: SPARK-3032 URL: https://issues.apache.org/jira/browse/SPARK-3032 Project: Spark Issue Type: Bug Components: Shuffle Affects Versions: 1.1.0 Reporter: Saisai Shao
When using SparkPerf's aggregate-by-key workload to test sort-based shuffle, data type for key and value is (String, String), always meet this issue: {noformat} java.lang.IllegalArgumentException: Comparison method violates its general contract! at org.apache.spark.util.collection.Sorter$SortState.mergeLo(Sorter.java:755) at org.apache.spark.util.collection.Sorter$SortState.mergeAt(Sorter.java:493) at org.apache.spark.util.collection.Sorter$SortState.mergeCollapse(Sorter.java:420) at org.apache.spark.util.collection.Sorter$SortState.access$200(Sorter.java:294) at org.apache.spark.util.collection.Sorter.sort(Sorter.java:128) at org.apache.spark.util.collection.SizeTrackingPairBuffer.destructiveSortedIterator(SizeTrackingPairBuffer.scala:83) at org.apache.spark.util.collection.ExternalSorter.spillToMergeableFile(ExternalSorter.scala:323) at org.apache.spark.util.collection.ExternalSorter.spill(ExternalSorter.scala:271) at org.apache.spark.util.collection.ExternalSorter.maybeSpill(ExternalSorter.scala:249) at org.apache.spark.util.collection.ExternalSorter.insertAll(ExternalSorter.scala:220) at org.apache.spark.shuffle.sort.SortShuffleWriter.write(SortShuffleWriter.scala:85) at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:68) at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:41) at org.apache.spark.scheduler.Task.run(Task.scala:54) at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:199) 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) {noformat} Seems the current partitionKeyComparator which use hashcode of String as key comparator break some sorting contracts. Also I tested using data type Int as key, this is OK to pass the test, since hashcode of Int is its self. So I think potentially partitionDiff + hashcode of String may break the sorting contracts. -- This message was sent by Atlassian JIRA (v6.2#6252) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org