JkSelf 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_r252141766
########## File path: sql/core/src/main/scala/org/apache/spark/sql/execution/adaptive/QueryStageTrigger.scala ########## @@ -0,0 +1,160 @@ +/* + * 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 scala.collection.mutable.{HashMap, HashSet, ListBuffer} +import scala.concurrent.{ExecutionContext, ExecutionContextExecutorService, Future} + +import org.apache.spark.sql.SparkSession +import org.apache.spark.sql.execution.SparkPlan +import org.apache.spark.util.{EventLoop, ThreadUtils} + +/** + * This class triggers [[QueryStage]] bottom-up, apply planner rules for query stages and + * materialize them. It triggers as many query stages as possible at the same time, and triggers + * the parent query stage when all its child stages are materialized. + */ +class QueryStageTrigger(session: SparkSession, callback: QueryStageTriggerCallback) + extends EventLoop[QueryStageTriggerEvent]("QueryStageTrigger") { + + private val stageToParentStages = HashMap.empty[Int, ListBuffer[QueryStage]] + + private val idToUpdatedStage = HashMap.empty[Int, QueryStage] + + private val stageToNumPendingChildStages = HashMap.empty[Int, Int] + + private val submittedStages = HashSet.empty[Int] + + private val readyStages = HashSet.empty[Int] + + private val planner = new QueryStagePlanner(session.sessionState.conf) + + def trigger(stage: QueryStage): Unit = { + post(SubmitStage(stage)) + } + + private implicit def executionContext: ExecutionContextExecutorService = { + QueryStageTrigger.executionContext + } + + override protected def onReceive(event: QueryStageTriggerEvent): Unit = event match { + case SubmitStage(stage) => + // We may submit a query stage multiple times, because of stage reuse. Here we avoid + // re-submitting a query stage. + if (!submittedStages.contains(stage.id)) { Review comment: Here the same query stage may be executed more than once when multi threads concurrency, for example the subqueries reuse. ---------------------------------------------------------------- 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]
