| /** |
| * 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.pig.backend.hadoop.executionengine.tez.plan.optimizer; |
| |
| import java.util.List; |
| |
| import org.apache.pig.backend.hadoop.executionengine.physicalLayer.plans.PhysicalPlan; |
| import org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POPackage; |
| import org.apache.pig.backend.hadoop.executionengine.physicalLayer.util.PlanHelper; |
| import org.apache.pig.backend.hadoop.executionengine.tez.plan.TezOpPlanVisitor; |
| import org.apache.pig.backend.hadoop.executionengine.tez.plan.TezOperPlan; |
| import org.apache.pig.backend.hadoop.executionengine.tez.plan.TezOperator; |
| import org.apache.pig.backend.hadoop.executionengine.tez.plan.operator.POLocalRearrangeTez; |
| import org.apache.pig.backend.hadoop.executionengine.util.CombinerOptimizerUtil; |
| import org.apache.pig.impl.plan.CompilationMessageCollector; |
| import org.apache.pig.impl.plan.DepthFirstWalker; |
| import org.apache.pig.impl.plan.VisitorException; |
| |
| /** |
| * Optimize tez plans to use the combiner where possible. |
| */ |
| public class CombinerOptimizer extends TezOpPlanVisitor { |
| private CompilationMessageCollector messageCollector = null; |
| private boolean doMapAgg; |
| |
| public CombinerOptimizer(TezOperPlan plan, boolean doMapAgg) { |
| this(plan, doMapAgg, new CompilationMessageCollector()); |
| } |
| |
| public CombinerOptimizer(TezOperPlan plan, boolean doMapAgg, |
| CompilationMessageCollector messageCollector) { |
| super(plan, new DepthFirstWalker<TezOperator, TezOperPlan>(plan)); |
| this.messageCollector = messageCollector; |
| this.doMapAgg = doMapAgg; |
| } |
| |
| public CompilationMessageCollector getMessageCollector() { |
| return messageCollector; |
| } |
| |
| @Override |
| public void visitTezOp(TezOperator to) throws VisitorException { |
| List<POPackage> packages = PlanHelper.getPhysicalOperators(to.plan, POPackage.class); |
| if (packages.isEmpty()) { |
| return; |
| } |
| |
| List<TezOperator> predecessors = mPlan.getPredecessors(to); |
| if (predecessors == null) { |
| return; |
| } |
| if (to.isCogroup()) { |
| return; |
| } |
| |
| for (TezOperator from : predecessors) { |
| PhysicalPlan combinePlan = to.inEdges.get(from.getOperatorKey()).combinePlan; |
| if (!combinePlan.isEmpty()) { |
| // Cases like bloom join have combine plan already set |
| continue; |
| } |
| List<POLocalRearrangeTez> rearranges = PlanHelper.getPhysicalOperators(from.plan, POLocalRearrangeTez.class); |
| if (rearranges.isEmpty()) { |
| continue; |
| } |
| |
| POLocalRearrangeTez connectingLR = null; |
| PhysicalPlan rearrangePlan = from.plan; |
| for (POLocalRearrangeTez lr : rearranges) { |
| if (lr.containsOutputKey(to.getOperatorKey().toString())) { |
| connectingLR = lr; |
| break; |
| } |
| } |
| |
| if (from.plan.getOperator(connectingLR.getOperatorKey()) == null) { |
| // The POLocalRearrange is sub-plan of a POSplit |
| rearrangePlan = PlanHelper.getLocalRearrangePlanFromSplit(from.plan, connectingLR.getOperatorKey()); |
| } |
| |
| // Detected the POLocalRearrange -> POPackage pattern. Let's add |
| // combiner if possible. |
| CombinerOptimizerUtil.addCombiner(rearrangePlan, to.plan, combinePlan, messageCollector, doMapAgg); |
| |
| if(!combinePlan.isEmpty()) { |
| // Override the requested parallelism for intermediate reducers |
| // when combiners are involved so that there are more tasks doing the combine |
| from.setOverrideIntermediateParallelism(true); |
| } |
| |
| } |
| } |
| |
| } |
| |