[SPARK-10719] SQLImplicits.rddToDataFrameHolder is not thread safe when using Scala 2.10

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Incomplete
• Affects Version/s: 1.3.1, 1.4.1, 1.5.0, 1.6.0
• Fix Version/s: 2.3.0
• Component/s: SQL
• Labels: bulk-closed

Environment

Scala 2.10

• Assignee: Shixiong Zhu
• Reporter: Shixiong Zhu
• Created: 20/Sep/15 16:04
• Updated: 21/May/19 17:45
• Resolved: 21/May/19 04:16

Description

Sometimes the following codes failed

    val conf = new SparkConf().setAppName("sql-memory-leak")
    val sc = new SparkContext(conf)
    val sqlContext = new SQLContext(sc)
    import sqlContext.implicits._
    (1 to 1000).par.foreach { _ =>
      sc.parallelize(1 to 5).map { i => (i, i) }.toDF("a", "b").count()
    }

The stack trace is

Exception in thread "main" java.lang.UnsupportedOperationException: tail of empty list
	at scala.collection.immutable.Nil$.tail(List.scala:339)
	at scala.collection.immutable.Nil$.tail(List.scala:334)
	at scala.reflect.internal.SymbolTable.popPhase(SymbolTable.scala:172)
	at scala.reflect.internal.Symbols$Symbol.unsafeTypeParams(Symbols.scala:1477)
	at scala.reflect.internal.Symbols$TypeSymbol.tpe(Symbols.scala:2777)
	at scala.reflect.internal.Mirrors$RootsBase.init(Mirrors.scala:235)
	at scala.reflect.runtime.JavaMirrors$class.createMirror(JavaMirrors.scala:34)
	at scala.reflect.runtime.JavaMirrors$class.runtimeMirror(JavaMirrors.scala:61)
	at scala.reflect.runtime.JavaUniverse.runtimeMirror(JavaUniverse.scala:12)
	at scala.reflect.runtime.JavaUniverse.runtimeMirror(JavaUniverse.scala:12)
	at SparkApp$$anonfun$main$1.apply$mcJI$sp(SparkApp.scala:16)
	at SparkApp$$anonfun$main$1.apply(SparkApp.scala:15)
	at SparkApp$$anonfun$main$1.apply(SparkApp.scala:15)
	at scala.Function1$class.apply$mcVI$sp(Function1.scala:39)
	at scala.runtime.AbstractFunction1.apply$mcVI$sp(AbstractFunction1.scala:12)
	at scala.collection.parallel.immutable.ParRange$ParRangeIterator.foreach(ParRange.scala:91)
	at scala.collection.parallel.ParIterableLike$Foreach.leaf(ParIterableLike.scala:975)
	at scala.collection.parallel.Task$$anonfun$tryLeaf$1.apply$mcV$sp(Tasks.scala:54)
	at scala.collection.parallel.Task$$anonfun$tryLeaf$1.apply(Tasks.scala:53)
	at scala.collection.parallel.Task$$anonfun$tryLeaf$1.apply(Tasks.scala:53)
	at scala.collection.parallel.Task$class.tryLeaf(Tasks.scala:56)
	at scala.collection.parallel.ParIterableLike$Foreach.tryLeaf(ParIterableLike.scala:972)
	at scala.collection.parallel.AdaptiveWorkStealingTasks$WrappedTask$class.internal(Tasks.scala:172)
	at scala.collection.parallel.AdaptiveWorkStealingForkJoinTasks$WrappedTask.internal(Tasks.scala:514)
	at scala.collection.parallel.AdaptiveWorkStealingTasks$WrappedTask$class.compute(Tasks.scala:162)
	at scala.collection.parallel.AdaptiveWorkStealingForkJoinTasks$WrappedTask.compute(Tasks.scala:514)
	at scala.concurrent.forkjoin.RecursiveAction.exec(RecursiveAction.java:160)
	at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
	at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
	at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
	at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)

Finally, I found the problem. The codes generated by Scala compiler to find the implicit TypeTag are not thread safe because of an issue in Scala 2.10: https://issues.scala-lang.org/browse/SI-6240
This issue was fixed in Scala 2.11 but not backported to 2.10.

Issue Links

• is related to: SPARK-19810 Remove support for Scala 2.10
• relates to: SPARK-13640 Synchronize ScalaReflection.mirror method.