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  1. Spark
  2. SPARK-21563

Race condition when serializing TaskDescriptions and adding jars



    • Bug
    • Status: Resolved
    • Major
    • Resolution: Fixed
    • 2.2.0
    • 2.2.1, 2.3.0
    • Scheduler, Spark Core
    • None


      cc robert3005

      I was seeing this exception during some running Spark jobs:

      16:16:28.294 [dispatcher-event-loop-14] ERROR org.apache.spark.rpc.netty.Inbox - Ignoring error
      java.io.EOFException: null
          at java.io.DataInputStream.readFully(DataInputStream.java:197)
          at java.io.DataInputStream.readUTF(DataInputStream.java:609)
          at java.io.DataInputStream.readUTF(DataInputStream.java:564)
          at org.apache.spark.scheduler.TaskDescription$$anonfun$decode$1.apply(TaskDescription.scala:127)
          at org.apache.spark.scheduler.TaskDescription$$anonfun$decode$1.apply(TaskDescription.scala:126)
          at scala.collection.immutable.Range.foreach(Range.scala:160)
          at org.apache.spark.scheduler.TaskDescription$.decode(TaskDescription.scala:126)
          at org.apache.spark.executor.CoarseGrainedExecutorBackend$$anonfun$receive$1.applyOrElse(CoarseGrainedExecutorBackend.scala:95)
          at org.apache.spark.rpc.netty.Inbox$$anonfun$process$1.apply$mcV$sp(Inbox.scala:117)
          at org.apache.spark.rpc.netty.Inbox.safelyCall(Inbox.scala:205)
          at org.apache.spark.rpc.netty.Inbox.process(Inbox.scala:101)
          at org.apache.spark.rpc.netty.Dispatcher$MessageLoop.run(Dispatcher.scala:213)
          at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
          at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
          at java.lang.Thread.run(Thread.java:748)

      After some debugging, we determined that this is due to a race condition in task serde. cc irashid kayousterhout who last touched that code in SPARK-19796

      The race is between adding additional jars to the SparkContext and serializing the TaskDescription.

      Consider this sequence of events:

      The problem now is that the jars list is serialized as having N entries, but actually N+1 entries follow that count!

      This causes task deserialization to fail in the executor, with the stacktrace above.

      The same issue also likely exists for files, though I haven't observed that and our application does not stress that codepath the same way it did for jar additions.

      One fix here is that TaskSetManager could make an immutable copy of the jars list that it passes into the TaskDescription constructor, so that list doesn't change mid-serialization.




            aash Andrew Ash
            aash Andrew Ash
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