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Apache Spark commented on SPARK-8498: ------------------------------------- User 'andrewor14' has created a pull request for this issue: https://github.com/apache/spark/pull/6909 > Fix NullPointerException in error-handling path in UnsafeShuffleWriter > ---------------------------------------------------------------------- > > Key: SPARK-8498 > URL: https://issues.apache.org/jira/browse/SPARK-8498 > Project: Spark > Issue Type: Bug > Components: Shuffle > Affects Versions: 1.4.0 > Reporter: Josh Rosen > Assignee: holdenk > Fix For: 1.5.0 > > > This bug was reported by [~prudenko] on the dev list. When the > {{tungsten-sort}} shuffle manager was enabled, an executor died with the > following exception: > {code} > 15/06/19 17:53:35 WARN TaskSetManager: Lost task 38.0 in stage 41.0 (TID > 3176, ip-10-50-225-214.ec2.internal): java.lang.NullPointerException > at > org.apache.spark.shuffle.unsafe.UnsafeShuffleWriter.write(UnsafeShuffleWriter.java:151) > at > org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:70) > at > org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:41) > at org.apache.spark.scheduler.Task.run(Task.scala:70) > at > org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:213) > at > java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) > at > java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) > at java.lang.Thread.run(Thread.java:745) > {code} > I think that this is actually due to an error-handling issue. In the stack > trace, the NPE is being thrown from an error-handling branch of a `finally` > block: > {code} > public void write(scala.collection.Iterator<Product2<K, V>> records) throws > IOException { > boolean success = false; > try { > while (records.hasNext()) { > insertRecordIntoSorter(records.next()); > } > closeAndWriteOutput(); > success = true; > } finally { > if (!success) { > sorter.cleanupAfterError(); // <---- this is the line throwing the > error > } > } > } > {code} > I suspect that what's happening is that an exception is being thrown from > user / upstream code in the initial call to records.next(), but the > error-handling block is failing because sorter == null since we haven't > initialized it yet. > We should fix this bug with a {{sorter != null}} check and should also add a > regression test to ShuffleSuite to ensure that exceptions thrown by user code > at this step of the shuffle write path don't get masked by error-handling > bugs inside of the shuffle code. -- 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