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* to you under the Apache License, Version 2.0 (the
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*
* http://www.apache.org/licenses/LICENSE-2.0
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* Unless required by applicable law or agreed to in writing, software
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package org.apache.flink.test.iterative.aggregators;
import java.util.ArrayList;
import java.util.List;
import org.apache.flink.api.common.aggregators.LongSumAggregator;
import org.apache.flink.api.common.functions.JoinFunction;
import org.apache.flink.api.common.functions.RichFlatMapFunction;
import org.apache.flink.api.common.functions.RichGroupReduceFunction;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.test.util.JavaProgramTestBase;
import org.apache.flink.types.LongValue;
import org.apache.flink.util.Collector;
import org.junit.Assert;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.operators.IterativeDataSet;
/**
* Connected Components test case that uses a parameterizable aggregator
*/
public class ConnectedComponentsWithParametrizableAggregatorITCase extends JavaProgramTestBase {
private static final int MAX_ITERATIONS = 5;
private static final int DOP = 1;
protected static List<Tuple2<Long, Long>> verticesInput = new ArrayList<Tuple2<Long, Long>>();
protected static List<Tuple2<Long, Long>> edgesInput = new ArrayList<Tuple2<Long, Long>>();
private String resultPath;
private String expectedResult;
@Override
protected void preSubmit() throws Exception {
// vertices input
verticesInput.clear();
verticesInput.add(new Tuple2<Long, Long>(1l,1l));
verticesInput.add(new Tuple2<Long, Long>(2l,2l));
verticesInput.add(new Tuple2<Long, Long>(3l,3l));
verticesInput.add(new Tuple2<Long, Long>(4l,4l));
verticesInput.add(new Tuple2<Long, Long>(5l,5l));
verticesInput.add(new Tuple2<Long, Long>(6l,6l));
verticesInput.add(new Tuple2<Long, Long>(7l,7l));
verticesInput.add(new Tuple2<Long, Long>(8l,8l));
verticesInput.add(new Tuple2<Long, Long>(9l,9l));
// vertices input
edgesInput.clear();
edgesInput.add(new Tuple2<Long, Long>(1l,2l));
edgesInput.add(new Tuple2<Long, Long>(1l,3l));
edgesInput.add(new Tuple2<Long, Long>(2l,3l));
edgesInput.add(new Tuple2<Long, Long>(2l,4l));
edgesInput.add(new Tuple2<Long, Long>(2l,1l));
edgesInput.add(new Tuple2<Long, Long>(3l,1l));
edgesInput.add(new Tuple2<Long, Long>(3l,2l));
edgesInput.add(new Tuple2<Long, Long>(4l,2l));
edgesInput.add(new Tuple2<Long, Long>(4l,6l));
edgesInput.add(new Tuple2<Long, Long>(5l,6l));
edgesInput.add(new Tuple2<Long, Long>(6l,4l));
edgesInput.add(new Tuple2<Long, Long>(6l,5l));
edgesInput.add(new Tuple2<Long, Long>(7l,8l));
edgesInput.add(new Tuple2<Long, Long>(7l,9l));
edgesInput.add(new Tuple2<Long, Long>(8l,7l));
edgesInput.add(new Tuple2<Long, Long>(8l,9l));
edgesInput.add(new Tuple2<Long, Long>(9l,7l));
edgesInput.add(new Tuple2<Long, Long>(9l,8l));
resultPath = getTempDirPath("result");
expectedResult = "(1,1)\n" + "(2,1)\n" + "(3,1)\n" + "(4,1)\n" +
"(5,1)\n" + "(6,1)\n" + "(7,7)\n" + "(8,7)\n" + "(9,7)\n";
}
@Override
protected void testProgram() throws Exception {
ConnectedComponentsWithAggregatorProgram.runProgram(resultPath);
}
@Override
protected void postSubmit() throws Exception {
compareResultsByLinesInMemory(expectedResult, resultPath);
long[] aggr_values = ConnectedComponentsWithAggregatorProgram.aggr_value;
// note that position 0 has the end result from superstep 1, retrieved at the start of iteration 2
// position one as superstep 2, retrieved at the start of iteration 3.
// the result from iteration 5 is not available, because no iteration 6 happens
Assert.assertEquals(3, aggr_values[0]);
Assert.assertEquals(4, aggr_values[1]);
Assert.assertEquals(5, aggr_values[2]);
Assert.assertEquals(6, aggr_values[3]);
}
private static class ConnectedComponentsWithAggregatorProgram {
private static final String ELEMENTS_IN_COMPONENT = "elements.in.component.aggregator";
private static final long componentId = 1l;
private static long [] aggr_value = new long [MAX_ITERATIONS];
public static String runProgram(String resultPath) throws Exception {
final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
env.setDegreeOfParallelism(DOP);
DataSet<Tuple2<Long, Long>> initialSolutionSet = env.fromCollection(verticesInput);
DataSet<Tuple2<Long, Long>> edges = env.fromCollection(edgesInput);
IterativeDataSet<Tuple2<Long, Long>> iteration =
initialSolutionSet.iterate(MAX_ITERATIONS);
// register the aggregator
iteration.registerAggregator(ELEMENTS_IN_COMPONENT, new LongSumAggregatorWithParameter(componentId));
DataSet<Tuple2<Long, Long>> verticesWithNewComponents = iteration.join(edges).where(0).equalTo(0)
.with(new NeighborWithComponentIDJoin())
.groupBy(0).reduceGroup(new MinimumReduce());
DataSet<Tuple2<Long, Long>> updatedComponentId =
verticesWithNewComponents.join(iteration).where(0).equalTo(0)
.flatMap(new MinimumIdFilter());
iteration.closeWith(updatedComponentId).writeAsText(resultPath);
env.execute();
return resultPath;
}
}
public static final class NeighborWithComponentIDJoin implements JoinFunction
<Tuple2<Long, Long>, Tuple2<Long, Long>, Tuple2<Long, Long>> {
private static final long serialVersionUID = 1L;
@Override
public Tuple2<Long, Long> join(Tuple2<Long, Long> vertexWithCompId,
Tuple2<Long, Long> edge) throws Exception {
vertexWithCompId.setField(edge.f1, 0);
return vertexWithCompId;
}
}
public static final class MinimumReduce extends RichGroupReduceFunction<Tuple2<Long, Long>, Tuple2<Long, Long>> {
private static final long serialVersionUID = 1L;
private final Tuple2<Long, Long> resultVertex = new Tuple2<Long, Long>();
@Override
public void reduce(Iterable<Tuple2<Long, Long>> values, Collector<Tuple2<Long, Long>> out) {
Long vertexId = 0L;
Long minimumCompId = Long.MAX_VALUE;
for (Tuple2<Long, Long> value: values) {
vertexId = value.f0;
Long candidateCompId = value.f1;
if (candidateCompId < minimumCompId) {
minimumCompId = candidateCompId;
}
}
resultVertex.f0 = vertexId;
resultVertex.f1 = minimumCompId;
out.collect(resultVertex);
}
}
@SuppressWarnings("serial")
public static final class MinimumIdFilter extends RichFlatMapFunction<Tuple2<Tuple2<Long, Long>, Tuple2<Long, Long>>, Tuple2<Long, Long>> {
private static LongSumAggregatorWithParameter aggr;
@Override
public void open(Configuration conf) {
aggr = getIterationRuntimeContext().getIterationAggregator(
ConnectedComponentsWithAggregatorProgram.ELEMENTS_IN_COMPONENT);
int superstep = getIterationRuntimeContext().getSuperstepNumber();
if (superstep > 1) {
LongValue val = getIterationRuntimeContext().getPreviousIterationAggregate(
ConnectedComponentsWithAggregatorProgram.ELEMENTS_IN_COMPONENT);
ConnectedComponentsWithAggregatorProgram.aggr_value[superstep-2] = val.getValue();
}
}
@Override
public void flatMap(
Tuple2<Tuple2<Long, Long>, Tuple2<Long, Long>> vertexWithNewAndOldId,
Collector<Tuple2<Long, Long>> out) throws Exception {
if (vertexWithNewAndOldId.f0.f1 < vertexWithNewAndOldId.f1.f1) {
out.collect(vertexWithNewAndOldId.f0);
if (vertexWithNewAndOldId.f0.f1 == aggr.getComponentId()) {
aggr.aggregate(1l);
}
} else {
out.collect(vertexWithNewAndOldId.f1);
if (vertexWithNewAndOldId.f1.f1 == aggr.getComponentId()) {
aggr.aggregate(1l);
}
}
}
}
// A LongSumAggregator with one parameter
@SuppressWarnings("serial")
public static final class LongSumAggregatorWithParameter extends LongSumAggregator {
private long componentId;
public LongSumAggregatorWithParameter(long compId) {
this.componentId = compId;
}
public long getComponentId() {
return this.componentId;
}
}
}