[SPARK-28939][SQL] Propagate SQLConf for plans executed by toRdd

sql/core/src/main/scala/org/apache/spark/sql/execution/QueryExecution.scala

@@ -105,7 +105,8 @@ class QueryExecution(
    * Given QueryExecution is not a public class, end users are discouraged to use this: please
    * use `Dataset.rdd` instead where conversion will be applied.
    */
-  lazy val toRdd: RDD[InternalRow] = executedPlan.execute()
+  lazy val toRdd: RDD[InternalRow] = new SQLExecutionRDD(
+    executedPlan.execute(), sparkSession.sessionState.conf)
 
   /**
    * Prepares a planned [[SparkPlan]] for execution by inserting shuffle operations and internal

sql/core/src/main/scala/org/apache/spark/sql/execution/SQLExecutionRDD.scala

@@ -0,0 +1,80 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.spark.sql.execution
+
+import org.apache.spark.{Partition, TaskContext}
+import org.apache.spark.rdd.RDD
+import org.apache.spark.sql.catalyst.InternalRow
+import org.apache.spark.sql.internal.SQLConf
+
+/**
+ * It is just a wrapper over `sqlRDD`, which sets and makes effective all the configs from the
+ * captured `SQLConf`.
+ * Please notice that this means we may miss configurations set after the creation of this RDD and
+ * before its execution.
+ *
+ * @param sqlRDD the `RDD` generated by the SQL plan
+ * @param conf the `SQLConf` to apply to the execution of the SQL plan
+ */
+class SQLExecutionRDD(
+    var sqlRDD: RDD[InternalRow], @transient conf: SQLConf) extends RDD[InternalRow](sqlRDD) {
+  private val sqlConfigs = conf.getAllConfs
+  @transient private var tasksRunning = 0
+  @transient private var originalLocalProps: Map[String, String] = _
+
+  override val partitioner = firstParent[InternalRow].partitioner
+
+  override def getPartitions: Array[Partition] = firstParent[InternalRow].partitions
+
+  override def compute(split: Partition, context: TaskContext): Iterator[InternalRow] = {
+    // If we are in the context of a tracked SQL operation, `SQLExecution.EXECUTION_ID_KEY` is set
+    // and we have nothing to do here. Otherwise, we use the `SQLConf` captured at the creation of
+    // this RDD.
+    if (context.getLocalProperty(SQLExecution.EXECUTION_ID_KEY) == null) {
+      synchronized {
+        if (tasksRunning == 0) {
+          originalLocalProps = sqlConfigs.collect {
+            case (key, value) if key.startsWith("spark") =>
+              val originalValue = context.getLocalProperty(key)
+              context.getLocalProperties.setProperty(key, value)
+              (key, originalValue)
+          }
+        }
+        tasksRunning += 1
+      }
+
+      try {
+        firstParent[InternalRow].iterator(split, context)
+      } finally {
+        synchronized {
+          tasksRunning -= 1
+          if (tasksRunning == 0) {
+            for ((key, value) <- originalLocalProps) {
+              if (value == null) {
+                context.getLocalProperties.remove(key)
+              } else {
+                context.getLocalProperties.setProperty(key, value)
+              }
+            }
+          }
+        }
+      }
+    } else {
+      firstParent[InternalRow].iterator(split, context)
+    }
+  }
+}

sql/core/src/test/scala/org/apache/spark/sql/internal/ExecutorSideSQLConfSuite.scala

@@ -17,8 +17,13 @@
 
 package org.apache.spark.sql.internal
 
-import org.apache.spark.SparkFunSuite
-import org.apache.spark.sql.{AnalysisException, SparkSession}
+import org.apache.spark.{SparkException, SparkFunSuite}
+import org.apache.spark.rdd.RDD
+import org.apache.spark.sql.SparkSession
+import org.apache.spark.sql.catalyst.InternalRow
+import org.apache.spark.sql.catalyst.expressions.Attribute
+import org.apache.spark.sql.catalyst.plans.logical.LocalRelation
+import org.apache.spark.sql.execution.{LeafExecNode, QueryExecution, SparkPlan}
 import org.apache.spark.sql.execution.debug.codegenStringSeq
 import org.apache.spark.sql.functions.col
 import org.apache.spark.sql.test.SQLTestUtils
@@ -102,4 +107,41 @@ class ExecutorSideSQLConfSuite extends SparkFunSuite with SQLTestUtils {
       }
     }
   }
+
+  test("SPARK-28939: propagate SQLConf also in conversions to RDD") {
+    val confs = Seq("spark.sql.a" -> "x", "spark.sql.b" -> "y")
+    val physicalPlan = SQLConfAssertPlan(confs)
+    val dummyQueryExecution = FakeQueryExecution(spark, physicalPlan)
+    withSQLConf(confs: _*) {
+      // Force RDD evaluation to trigger asserts
+      dummyQueryExecution.toRdd.collect()
+    }
+    val dummyQueryExecution1 = FakeQueryExecution(spark, physicalPlan)
+    // Without setting the configs assertions fail
+    val e = intercept[SparkException](dummyQueryExecution1.toRdd.collect())
+    assert(e.getCause.isInstanceOf[NoSuchElementException])
+  }
+}
+
+case class SQLConfAssertPlan(confToCheck: Seq[(String, String)]) extends LeafExecNode {
+  override protected def doExecute(): RDD[InternalRow] = {
+    sqlContext
+      .sparkContext
+      .parallelize(0 until 2, 2)
+      .mapPartitions { it =>
+        val confs = SQLConf.get
+        confToCheck.foreach { case (key, expectedValue) =>
+          assert(confs.getConfString(key) == expectedValue)
+        }
+        it.map(i => InternalRow.fromSeq(Seq(i)))
+      }
+  }
+
+  override def output: Seq[Attribute] = Seq.empty
+}
+
+case class FakeQueryExecution(spark: SparkSession, physicalPlan: SparkPlan)
+    extends QueryExecution(spark, LocalRelation()) {
+  override lazy val sparkPlan: SparkPlan = physicalPlan
+  override lazy val executedPlan: SparkPlan = physicalPlan
 }