[ https://issues.apache.org/jira/browse/SPARK-23598?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16412835#comment-16412835 ]
Dongjoon Hyun commented on SPARK-23598: --------------------------------------- Hi, [~hvanhovell] and [~kiszk]. Although this test case is failing in `branch-2.3` sometimes, I added `2.3.1` to `Fixed Versions` because the patch landed on `branch-2.3`. - https://amplab.cs.berkeley.edu/jenkins/view/Spark%20QA%20Test%20(Dashboard)/job/spark-branch-2.3-test-sbt-hadoop-2.6/lastCompletedBuild/testReport/org.apache.spark.sql.execution/WholeStageCodegenSuite/SPARK_23598__Codegen_working_for_lots_of_aggregation_operations_without_runtime_errors/ > WholeStageCodegen can lead to IllegalAccessError calling append for > HashAggregateExec > -------------------------------------------------------------------------------------- > > Key: SPARK-23598 > URL: https://issues.apache.org/jira/browse/SPARK-23598 > Project: Spark > Issue Type: Bug > Components: Spark Core > Affects Versions: 2.4.0 > Reporter: David Vogelbacher > Assignee: Kazuaki Ishizaki > Priority: Major > Fix For: 2.3.1, 2.4.0 > > > Got the following stacktrace for a large QueryPlan using WholeStageCodeGen: > {noformat} > java.lang.IllegalAccessError: tried to access method > org.apache.spark.sql.execution.BufferedRowIterator.append(Lorg/apache/spark/sql/catalyst/InternalRow;)V > from class > org.apache.spark.sql.catalyst.expressions.GeneratedClass$GeneratedIteratorForCodegenStage7$agg_NestedClass > at > org.apache.spark.sql.catalyst.expressions.GeneratedClass$GeneratedIteratorForCodegenStage7$agg_NestedClass.agg_doAggregateWithKeysOutput$(Unknown > Source) > at > org.apache.spark.sql.catalyst.expressions.GeneratedClass$GeneratedIteratorForCodegenStage7.processNext(Unknown > Source) > at > org.apache.spark.sql.execution.BufferedRowIterator.hasNext(BufferedRowIterator.java:43) > at > org.apache.spark.sql.execution.WholeStageCodegenExec$$anonfun$10$$anon$1.hasNext(WholeStageCodegenExec.scala:614) > at scala.collection.Iterator$$anon$11.hasNext(Iterator.scala:408) > at > org.apache.spark.shuffle.sort.BypassMergeSortShuffleWriter.write(BypassMergeSortShuffleWriter.java:125) > at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:96) > at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:53) > at org.apache.spark.scheduler.Task.run(Task.scala:109) > at > org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:345){noformat} > After disabling codegen, everything works. > The root cause seems to be that we are trying to call the protected _append_ > method of > [BufferedRowIterator|https://github.com/apache/spark/blob/master/sql/core/src/main/java/org/apache/spark/sql/execution/BufferedRowIterator.java#L68] > from an inner-class of a sub-class that is loaded by a different > class-loader (after codegen compilation). > [https://docs.oracle.com/javase/specs/jvms/se7/html/jvms-5.html#jvms-5.4.4] > states that a protected method _R_ can be accessed only if one of the > following two conditions is fulfilled: > # R is protected and is declared in a class C, and D is either a subclass of > C or C itself. Furthermore, if R is not static, then the symbolic reference > to R must contain a symbolic reference to a class T, such that T is either a > subclass of D, a superclass of D, or D itself. > # R is either protected or has default access (that is, neither public nor > protected nor private), and is declared by a class in the same run-time > package as D. > 2.) doesn't apply as we have loaded the class with a different class loader > (and are in a different package) and 1.) doesn't apply because we are > apparently trying to call the method from an inner class of a subclass of > _BufferedRowIterator_. > Looking at the Code path of _WholeStageCodeGen_, the following happens: > # In > [WholeStageCodeGen|https://github.com/apache/spark/blob/master/sql/core/src/main/scala/org/apache/spark/sql/execution/WholeStageCodegenExec.scala#L527], > we create the subclass of _BufferedRowIterator_, along with a _processNext_ > method for processing the output of the child plan. > # In the child, which is a > [HashAggregateExec|https://github.com/apache/spark/blob/master/sql/core/src/main/scala/org/apache/spark/sql/execution/aggregate/HashAggregateExec.scala#L517], > we create the method which shows up at the top of the stack trace (called > _doAggregateWithKeysOutput_ ) > # We add this method to the compiled code invoking _addNewFunction_ of > [CodeGenerator|https://github.com/apache/spark/blob/master/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/codegen/CodeGenerator.scala#L460] > In the generated function body we call the _append_ method.| > Now, the _addNewFunction_ method states that: > {noformat} > If the code for the `OuterClass` grows too large, the function will be > inlined into a new private, inner class > {noformat} > This indeed seems to happen: the _doAggregateWithKeysOutput_ method is put > into a new private inner class. Thus, it doesn't have access to the protected > _append_ method anymore but still tries to call it, which results in the > _IllegalAccessError._ > Possible fixes: > * Pass in the _inlineToOuterClass_ flag when invoking the _addNewFunction_ > * Make the _append_ method public > * Re-declare the _append_ method in the generated subclass (just invoking > _super_). This way, inner classes should have access to it. > -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org