/*
* 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.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.pig.backend.hadoop.executionengine.optimizer.SecondaryKeyOptimizer;
import org.apache.pig.backend.hadoop.executionengine.physicalLayer.plans.PhysicalPlan;
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.POLocalRearrangeTez;
import org.apache.pig.backend.hadoop.executionengine.util.SecondaryKeyOptimizerUtil;
import org.apache.pig.backend.hadoop.executionengine.util.SecondaryKeyOptimizerUtil.SecondaryKeyOptimizerInfo;
import org.apache.pig.classification.InterfaceAudience;
import org.apache.pig.impl.plan.DependencyOrderWalker;
import org.apache.pig.impl.plan.VisitorException;
@InterfaceAudience.Private
public class SecondaryKeyOptimizerTez extends TezOpPlanVisitor implements SecondaryKeyOptimizer {
private static Log log = LogFactory.getLog(SecondaryKeyOptimizerTez.class);
private int numSortRemoved = 0;
private int numDistinctChanged = 0;
private int numUseSecondaryKey = 0;
public SecondaryKeyOptimizerTez(TezOperPlan plan) {
super(plan, new DependencyOrderWalker<TezOperator, TezOperPlan>(plan));
}
@Override
public void visitTezOp(TezOperator to) throws VisitorException {
List<TezOperator> predecessors = mPlan.getPredecessors(to);
if (predecessors == null) {
return;
}
// Current code does not handle more than one predecessors
// even though it is possible. The problem is when we
// process the first predecessor, we remove the foreach inner
// operators from the reduce side, and the second predecessor
// cannot see them
if (predecessors.size()>1) {
return;
}
TezOperator from = predecessors.get(0);
List<POLocalRearrangeTez> rearranges = PlanHelper.getPhysicalOperators(from.plan, POLocalRearrangeTez.class);
if (rearranges.isEmpty()) {
return;
}
POLocalRearrangeTez connectingLR = null;
PhysicalPlan rearrangePlan = from.plan;
for (POLocalRearrangeTez lr : rearranges) {
if (lr.getOutputKey().equals(to.getOperatorKey().toString())) {
connectingLR = lr;
break;
}
}
if (connectingLR == null) {
return;
}
// Detected the POLocalRearrange -> POPackage pattern
TezEdgeDescriptor inEdge = to.inEdges.get(from.getOperatorKey());
// Only optimize for Cogroup case
if (from.isGlobalSort()) {
return;
}
// If there is a custom partitioner do not do secondary key optimization.
if (inEdge.partitionerClass != null) {
return;
}
if (from.plan.getOperator(connectingLR.getOperatorKey()) == null) {
// The POLocalRearrange is sub-plan of a POSplit
rearrangePlan = PlanHelper.getLocalRearrangePlanFromSplit(from.plan, connectingLR.getOperatorKey());
}
SecondaryKeyOptimizerInfo info = SecondaryKeyOptimizerUtil.applySecondaryKeySort(rearrangePlan, to.plan);
if (info != null) {
numSortRemoved += info.getNumSortRemoved();
numDistinctChanged += info.getNumDistinctChanged();
numUseSecondaryKey += info.getNumUseSecondaryKey();
if (info.isUseSecondaryKey()) {
// Set it on the receiving vertex and the connecting edge.
to.setUseSecondaryKey(true);
inEdge.setUseSecondaryKey(true);
inEdge.setSecondarySortOrder(info.getSecondarySortOrder());
log.info("Using Secondary Key Optimization in the edge between vertex - "
+ from.getOperatorKey()
+ " and vertex - "
+ to.getOperatorKey());
}
}
}
@Override
public int getNumSortRemoved() {
return numSortRemoved;
}
@Override
public int getNumDistinctChanged() {
return numDistinctChanged;
}
@Override
public int getNumUseSecondaryKey() {
return numUseSecondaryKey;
}
}