walterddr commented on a change in pull request #8340: URL: https://github.com/apache/pinot/pull/8340#discussion_r830154691
########## File path: pinot-query-planner/src/main/java/org/apache/pinot/query/planner/StagePlanner.java ########## @@ -0,0 +1,120 @@ +/** + * 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.pinot.query.planner; + +import java.util.HashMap; +import java.util.List; +import java.util.Map; +import org.apache.calcite.rel.RelDistribution; +import org.apache.calcite.rel.RelNode; +import org.apache.calcite.rel.RelRoot; +import org.apache.calcite.rel.logical.LogicalExchange; +import org.apache.pinot.query.context.PlannerContext; +import org.apache.pinot.query.planner.nodes.MailboxReceiveNode; +import org.apache.pinot.query.planner.nodes.MailboxSendNode; +import org.apache.pinot.query.planner.nodes.StageNode; +import org.apache.pinot.query.routing.WorkerManager; + + +/** + * QueryPlanMaker walks top-down from {@link RelRoot} and construct a forest of trees with {@link StageNode}. + * + * This class is non-threadsafe. Do not reuse the stage planner for multiple query plans. + */ +public class StagePlanner { + private final PlannerContext _plannerContext; + private final WorkerManager _workerManager; + + private Map<String, StageNode> _queryStageMap; + private Map<String, StageMetadata> _stageMetadataMap; + private int _stageIdCounter; + + public StagePlanner(PlannerContext plannerContext, WorkerManager workerManager) { + _plannerContext = plannerContext; + _workerManager = workerManager; + } + + public QueryPlan makePlan(RelNode relRoot) { + // clear the state + _queryStageMap = new HashMap<>(); + _stageMetadataMap = new HashMap<>(); + _stageIdCounter = 0; + + // walk the plan and create stages. + StageNode globalStageRoot = walkRelPlan(relRoot, getNewStageId()); + + // global root needs to send results back to the ROOT, a.k.a. the client response node. + // the last stage is always a broadcast-gather. + StageNode globalReceiverNode = + new MailboxReceiveNode("ROOT", globalStageRoot.getStageId(), RelDistribution.Type.BROADCAST_DISTRIBUTED); + StageNode globalSenderNode = new MailboxSendNode(globalStageRoot, globalReceiverNode.getStageId(), + RelDistribution.Type.BROADCAST_DISTRIBUTED); + _queryStageMap.put(globalSenderNode.getStageId(), globalSenderNode); + StageMetadata stageMetadata = _stageMetadataMap.get(globalSenderNode.getStageId()); + stageMetadata.attach(globalSenderNode); + + _queryStageMap.put(globalReceiverNode.getStageId(), globalReceiverNode); + StageMetadata globalReceivingStageMetadata = new StageMetadata(); + globalReceivingStageMetadata.attach(globalReceiverNode); + _stageMetadataMap.put(globalReceiverNode.getStageId(), globalReceivingStageMetadata); + + // assign workers to each stage. + for (Map.Entry<String, StageMetadata> e : _stageMetadataMap.entrySet()) { + _workerManager.assignWorkerToStage(e.getKey(), e.getValue()); + } + + return new QueryPlan(_queryStageMap, _stageMetadataMap); + } + + // non-threadsafe + private StageNode walkRelPlan(RelNode node, String currentStageId) { + if (isExchangeNode(node)) { + // 1. exchangeNode always have only one input, get its input converted as a new stage root. + StageNode nextStageRoot = walkRelPlan(node.getInput(0), getNewStageId()); + RelDistribution.Type exchangeType = ((LogicalExchange) node).distribution.getType(); + + // 2. make an exchange sender and receiver node pair + StageNode mailboxReceiver = new MailboxReceiveNode(currentStageId, nextStageRoot.getStageId(), exchangeType); + StageNode mailboxSender = new MailboxSendNode(nextStageRoot, mailboxReceiver.getStageId(), exchangeType); + + // 3. put the sender side as a completed stage. + _queryStageMap.put(mailboxSender.getStageId(), mailboxSender); + + // 4. return the receiver (this is considered as a "virtual table scan" node for its parent. + return mailboxReceiver; + } else { + StageNode stageNode = StageNodeConverter.toStageNode(node, currentStageId); + List<RelNode> inputs = node.getInputs(); + for (RelNode input : inputs) { + stageNode.addInput(walkRelPlan(input, currentStageId)); + } + StageMetadata stageMetadata = _stageMetadataMap.computeIfAbsent(currentStageId, (id) -> new StageMetadata()); + stageMetadata.attach(stageNode); + return stageNode; + } + } + + private boolean isExchangeNode(RelNode node) { + return (node instanceof LogicalExchange); + } + + private String getNewStageId() { + return String.valueOf(_stageIdCounter++); Review comment: yeah that make sense. currently i use stage string for ease of debugging purpose. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: commits-unsubscr...@pinot.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@pinot.apache.org For additional commands, e-mail: commits-h...@pinot.apache.org
