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* 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,
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package org.apache.pig.backend.hadoop.executionengine.tez.plan.optimizer;
import java.util.ArrayList;
import java.util.List;
import java.util.Map.Entry;
import org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator;
import org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.POUserFunc;
import org.apache.pig.backend.hadoop.executionengine.physicalLayer.plans.PhysicalPlan;
import org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POSplit;
import org.apache.pig.backend.hadoop.executionengine.physicalLayer.util.PlanHelper;
import org.apache.pig.backend.hadoop.executionengine.tez.plan.TezEdgeDescriptor;
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.POValueOutputTez;
import org.apache.pig.backend.hadoop.executionengine.tez.plan.udf.ReadScalarsTez;
import org.apache.pig.backend.hadoop.executionengine.tez.runtime.TezInput;
import org.apache.pig.backend.hadoop.executionengine.tez.util.TezCompilerUtil;
import org.apache.pig.impl.plan.OperatorKey;
import org.apache.pig.impl.plan.PlanException;
import org.apache.pig.impl.plan.ReverseDependencyOrderWalker;
import org.apache.pig.impl.plan.VisitorException;
public class MultiQueryOptimizerTez extends TezOpPlanVisitor {
public MultiQueryOptimizerTez(TezOperPlan plan) {
super(plan, new ReverseDependencyOrderWalker<TezOperator, TezOperPlan>(plan));
}
@Override
public void visitTezOp(TezOperator tezOp) throws VisitorException {
try {
if (!tezOp.isSplitter()) {
return;
}
List<TezOperator> splittees = new ArrayList<TezOperator>();
List<TezOperator> successors = getPlan().getSuccessors(tezOp);
List<TezOperator> succ_successors = new ArrayList<TezOperator>();
for (TezOperator successor : successors) {
// If has other dependency, don't merge into split,
if (getPlan().getPredecessors(successor).size()!=1) {
continue;
}
// Detect diamond shape, we cannot merge it into split, since Tez
// does not handle double edge between vertexes
// TODO: PIG-3876 to handle this by writing to same edge
boolean sharedSucc = false;
if (getPlan().getSuccessors(successor)!=null) {
for (TezOperator succ_successor : getPlan().getSuccessors(successor)) {
if (succ_successors.contains(succ_successor)) {
sharedSucc = true;
break;
}
}
succ_successors.addAll(getPlan().getSuccessors(successor));
}
if (sharedSucc) {
continue;
}
splittees.add(successor);
}
if (splittees.size()==0) {
return;
}
if (splittees.size()==1 && successors.size()==1) {
// We don't need a POSplit here, we can merge the splittee into spliter
PhysicalOperator firstNodeLeaf = tezOp.plan.getLeaves().get(0);
PhysicalOperator firstNodeLeafPred = tezOp.plan.getPredecessors(firstNodeLeaf).get(0);
TezOperator singleSplitee = splittees.get(0);
PhysicalOperator secondNodeRoot = singleSplitee.plan.getRoots().get(0);
PhysicalOperator secondNodeSucc = singleSplitee.plan.getSuccessors(secondNodeRoot).get(0);
tezOp.plan.remove(firstNodeLeaf);
singleSplitee.plan.remove(secondNodeRoot);
tezOp.plan.merge(singleSplitee.plan);
tezOp.plan.connect(firstNodeLeafPred, secondNodeSucc);
addSubPlanPropertiesToParent(tezOp, singleSplitee);
removeSplittee(getPlan(), tezOp, singleSplitee);
} else {
POValueOutputTez valueOutput = (POValueOutputTez)tezOp.plan.getLeaves().get(0);
POSplit split = new POSplit(OperatorKey.genOpKey(valueOutput.getOperatorKey().getScope()));
split.copyAliasFrom(valueOutput);
for (TezOperator splitee : splittees) {
PhysicalOperator spliteeRoot = splitee.plan.getRoots().get(0);
splitee.plan.remove(spliteeRoot);
split.addPlan(splitee.plan);
addSubPlanPropertiesToParent(tezOp, splitee);
removeSplittee(getPlan(), tezOp, splitee);
valueOutput.removeOutputKey(splitee.getOperatorKey().toString());
}
if (valueOutput.getTezOutputs().length > 0) {
// We still need valueOutput
PhysicalPlan phyPlan = new PhysicalPlan();
phyPlan.addAsLeaf(valueOutput);
split.addPlan(phyPlan);
}
PhysicalOperator pred = tezOp.plan.getPredecessors(valueOutput).get(0);
tezOp.plan.disconnect(pred, valueOutput);
tezOp.plan.remove(valueOutput);
tezOp.plan.add(split);
tezOp.plan.connect(pred, split);
}
} catch (PlanException e) {
throw new VisitorException(e);
}
}
static public void removeSplittee(TezOperPlan plan, TezOperator splitter, TezOperator splittee) throws PlanException {
if (plan.getSuccessors(splittee)!=null) {
List<TezOperator> succs = new ArrayList<TezOperator>();
succs.addAll(plan.getSuccessors(splittee));
plan.disconnect(splitter, splittee);
for (TezOperator succTezOperator : succs) {
TezEdgeDescriptor edge = succTezOperator.inEdges.get(splittee.getOperatorKey());
splitter.outEdges.remove(splittee.getOperatorKey());
succTezOperator.inEdges.remove(splittee.getOperatorKey());
plan.disconnect(splittee, succTezOperator);
TezCompilerUtil.connect(plan, splitter, succTezOperator, edge);
try {
List<TezInput> inputs = PlanHelper.getPhysicalOperators(succTezOperator.plan, TezInput.class);
for (TezInput input : inputs) {
input.replaceInput(splittee.getOperatorKey().toString(),
splitter.getOperatorKey().toString());
}
List<POUserFunc> userFuncs = PlanHelper.getPhysicalOperators(succTezOperator.plan, POUserFunc.class);
for (POUserFunc userFunc : userFuncs) {
if (userFunc.getFunc() instanceof ReadScalarsTez) {
TezInput tezInput = (TezInput)userFunc.getFunc();
tezInput.replaceInput(splittee.getOperatorKey().toString(),
splitter.getOperatorKey().toString());
userFunc.getFuncSpec().setCtorArgs(tezInput.getTezInputs());
}
}
} catch (VisitorException e) {
throw new PlanException(e);
}
if (succTezOperator.isUnion()) {
int index = succTezOperator.getUnionPredecessors().indexOf(splittee.getOperatorKey());
if (index > -1) {
succTezOperator.getUnionPredecessors().set(index, splitter.getOperatorKey());
}
}
}
}
plan.remove(splittee);
}
static public void addSubPlanPropertiesToParent(TezOperator parentOper, TezOperator subPlanOper) {
// Copy only map side properties. For eg: crossKeys.
// Do not copy reduce side specific properties. For eg: useSecondaryKey, segmentBelow, sortOrder, etc
if (subPlanOper.getCrossKeys() != null) {
for (String key : subPlanOper.getCrossKeys()) {
parentOper.addCrossKey(key);
}
}
parentOper.copyFeatures(subPlanOper, null);
if (subPlanOper.getRequestedParallelism() > parentOper.getRequestedParallelism()) {
parentOper.setRequestedParallelism(subPlanOper.getRequestedParallelism());
}
subPlanOper.setRequestedParallelismByReference(parentOper);
parentOper.UDFs.addAll(subPlanOper.UDFs);
parentOper.scalars.addAll(subPlanOper.scalars);
if (subPlanOper.outEdges != null) {
for (Entry<OperatorKey, TezEdgeDescriptor> entry: subPlanOper.outEdges.entrySet()) {
parentOper.outEdges.put(entry.getKey(), entry.getValue());
}
}
}
}