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Andrew Ash edited comment on SPARK-3032 at 9/25/14 10:35 PM: ------------------------------------------------------------- This bug prevents people from doing further testing of sort-based shuffle on the rest of the 1.1.x series. Is this a good candidate for a backport to 1.1.1 or a later 1.1 hotfix ? was (Author: aash): This bug prevents people from doing testing of sort-based shuffle on the rest of the 1.1.x series. Is this a good candidate for a backport to 1.1 ? > 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 > Assignee: Saisai Shao > Priority: Blocker > > 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 (v6.3.4#6332) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org