carsonwang commented on a change in pull request #20303: [SPARK-23128][SQL] A new approach to do adaptive execution in Spark SQL URL: https://github.com/apache/spark/pull/20303#discussion_r259722139
########## File path: sql/core/src/main/scala/org/apache/spark/sql/execution/adaptive/AdaptiveSparkPlan.scala ########## @@ -0,0 +1,111 @@ +/* + * 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.adaptive + +import java.util.concurrent.CountDownLatch + +import org.apache.spark.SparkException +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.execution.{LeafExecNode, SparkPlan, SparkPlanInfo, SQLExecution} +import org.apache.spark.sql.execution.ui.SparkListenerSQLAdaptiveExecutionUpdate + +/** + * A root node to execute the query plan adaptively. It creates query stages, and incrementally + * updates the query plan when a query stage is materialized and provides accurate runtime + * data statistics. + */ +case class AdaptiveSparkPlan(initialPlan: SparkPlan, session: SparkSession) + extends LeafExecNode{ + + override def output: Seq[Attribute] = initialPlan.output + + @volatile private var currentPlan: SparkPlan = initialPlan + @volatile private var error: Throwable = null + + // We will release the lock when we finish planning query stages, or we fail to do the planning. + // Getting `resultStage` will be blocked until the lock is release. + // This is better than wait()/notify(), as we can easily check if the computation has completed, + // by calling `readyLock.getCount()`. + private val readyLock = new CountDownLatch(1) + + private def createCallback(executionId: Option[Long]): QueryStageCreatorCallback = { + new QueryStageCreatorCallback { + override def onPlanUpdate(updatedPlan: SparkPlan): Unit = { + updateCurrentPlan(updatedPlan, executionId) + if (updatedPlan.isInstanceOf[ResultQueryStage]) readyLock.countDown() + } + + override def onStageMaterializingFailed(stage: QueryStage, e: Throwable): Unit = { + error = new SparkException( + s""" + |Fail to materialize stage ${stage.id}: + |${stage.plan.treeString} + """.stripMargin, e) + readyLock.countDown() + } + + override def onError(e: Throwable): Unit = { + error = e + readyLock.countDown() + } + } + } + + private def updateCurrentPlan(newPlan: SparkPlan, executionId: Option[Long]): Unit = { + currentPlan = newPlan + executionId.foreach { id => + session.sparkContext.listenerBus.post(SparkListenerSQLAdaptiveExecutionUpdate( + id, + SQLExecution.getQueryExecution(id).toString, + SparkPlanInfo.fromSparkPlan(currentPlan))) + } + } + + def finalPlan: ResultQueryStage = { + if (readyLock.getCount > 0) { Review comment: It should only be called in a single thread. @cloud-fan may confirm it. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
