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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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package org.apache.flink.test.iterative.aggregators;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import org.apache.flink.api.common.aggregators.ConvergenceCriterion;
import org.apache.flink.api.common.aggregators.LongSumAggregator;
import org.apache.flink.api.common.functions.RichFlatMapFunction;
import org.apache.flink.api.common.functions.RichJoinFunction;
import org.apache.flink.api.java.operators.DeltaIteration;
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.test.util.MultipleProgramsTestBase;
import org.apache.flink.types.LongValue;
import org.apache.flink.util.Collector;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.operators.IterativeDataSet;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import static org.junit.Assert.*;
/**
* Connected Components test case that uses a parameterizable convergence criterion
*/
@RunWith(Parameterized.class)
@SuppressWarnings("serial")
public class AggregatorConvergenceITCase extends MultipleProgramsTestBase {
public AggregatorConvergenceITCase(TestExecutionMode mode) {
super(mode);
}
final List<Tuple2<Long, Long>> verticesInput = Arrays.asList(
new Tuple2<>(1l,1l),
new Tuple2<>(2l,2l),
new Tuple2<>(3l,3l),
new Tuple2<>(4l,4l),
new Tuple2<>(5l,5l),
new Tuple2<>(6l,6l),
new Tuple2<>(7l,7l),
new Tuple2<>(8l,8l),
new Tuple2<>(9l,9l)
);
final List<Tuple2<Long, Long>> edgesInput = Arrays.asList(
new Tuple2<>(1l,2l),
new Tuple2<>(1l,3l),
new Tuple2<>(2l,3l),
new Tuple2<>(2l,4l),
new Tuple2<>(2l,1l),
new Tuple2<>(3l,1l),
new Tuple2<>(3l,2l),
new Tuple2<>(4l,2l),
new Tuple2<>(4l,6l),
new Tuple2<>(5l,6l),
new Tuple2<>(6l,4l),
new Tuple2<>(6l,5l),
new Tuple2<>(7l,8l),
new Tuple2<>(7l,9l),
new Tuple2<>(8l,7l),
new Tuple2<>(8l,9l),
new Tuple2<>(9l,7l),
new Tuple2<>(9l,8l)
);
final List<Tuple2<Long, Long>> expectedResult = Arrays.asList(
new Tuple2<>(1L,1L),
new Tuple2<>(2L,1L),
new Tuple2<>(3L,1L),
new Tuple2<>(4L,1L),
new Tuple2<>(5L,2L),
new Tuple2<>(6L,1L),
new Tuple2<>(7L,7L),
new Tuple2<>(8L,7L),
new Tuple2<>(9L,7L)
);
@Test
public void testConnectedComponentsWithParametrizableConvergence() throws Exception {
// name of the aggregator that checks for convergence
final String UPDATED_ELEMENTS = "updated.elements.aggr";
// the iteration stops if less than this number of elements change value
final long convergence_threshold = 3;
final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
DataSet<Tuple2<Long, Long>> initialSolutionSet = env.fromCollection(verticesInput);
DataSet<Tuple2<Long, Long>> edges = env.fromCollection(edgesInput);
IterativeDataSet<Tuple2<Long, Long>> iteration = initialSolutionSet.iterate(10);
// register the convergence criterion
iteration.registerAggregationConvergenceCriterion(UPDATED_ELEMENTS,
new LongSumAggregator(), new UpdatedElementsConvergenceCriterion(convergence_threshold));
DataSet<Tuple2<Long, Long>> verticesWithNewComponents = iteration.join(edges).where(0).equalTo(0)
.with(new NeighborWithComponentIDJoin())
.groupBy(0).min(1);
DataSet<Tuple2<Long, Long>> updatedComponentId =
verticesWithNewComponents.join(iteration).where(0).equalTo(0)
.flatMap(new MinimumIdFilter(UPDATED_ELEMENTS));
List<Tuple2<Long, Long>> result = iteration.closeWith(updatedComponentId).collect();
Collections.sort(result, new JavaProgramTestBase.TupleComparator<Tuple2<Long, Long>>());
assertEquals(expectedResult, result);
}
@Test
public void testDeltaConnectedComponentsWithParametrizableConvergence() throws Exception {
// name of the aggregator that checks for convergence
final String UPDATED_ELEMENTS = "updated.elements.aggr";
// the iteration stops if less than this number of elements change value
final long convergence_threshold = 3;
final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
DataSet<Tuple2<Long, Long>> initialSolutionSet = env.fromCollection(verticesInput);
DataSet<Tuple2<Long, Long>> edges = env.fromCollection(edgesInput);
DeltaIteration<Tuple2<Long, Long>, Tuple2<Long, Long>> iteration =
initialSolutionSet.iterateDelta(initialSolutionSet, 10, 0);
// register the convergence criterion
iteration.registerAggregationConvergenceCriterion(UPDATED_ELEMENTS,
new LongSumAggregator(), new UpdatedElementsConvergenceCriterion(convergence_threshold));
DataSet<Tuple2<Long, Long>> verticesWithNewComponents = iteration.getWorkset().join(edges).where(0).equalTo(0)
.with(new NeighborWithComponentIDJoin())
.groupBy(0).min(1);
DataSet<Tuple2<Long, Long>> updatedComponentId =
verticesWithNewComponents.join(iteration.getSolutionSet()).where(0).equalTo(0)
.flatMap(new MinimumIdFilter(UPDATED_ELEMENTS));
List<Tuple2<Long, Long>> result = iteration.closeWith(updatedComponentId, updatedComponentId).collect();
Collections.sort(result, new JavaProgramTestBase.TupleComparator<Tuple2<Long, Long>>());
assertEquals(expectedResult, result);
}
@Test
public void testParameterizableAggregator() throws Exception {
final int MAX_ITERATIONS = 5;
final String AGGREGATOR_NAME = "elements.in.component.aggregator";
final long componentId = 1l;
final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
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(AGGREGATOR_NAME, new LongSumAggregatorWithParameter(componentId));
DataSet<Tuple2<Long, Long>> verticesWithNewComponents = iteration.join(edges).where(0).equalTo(0)
.with(new NeighborWithComponentIDJoin())
.groupBy(0).min(1);
DataSet<Tuple2<Long, Long>> updatedComponentId =
verticesWithNewComponents.join(iteration).where(0).equalTo(0)
.flatMap(new MinimumIdFilterCounting(AGGREGATOR_NAME));
List<Tuple2<Long, Long>> result = iteration.closeWith(updatedComponentId).collect();
Collections.sort(result, new JavaProgramTestBase.TupleComparator<Tuple2<Long, Long>>());
List<Tuple2<Long, Long>> expectedResult = Arrays.asList(
new Tuple2<>(1L,1L),
new Tuple2<>(2L,1L),
new Tuple2<>(3L,1L),
new Tuple2<>(4L,1L),
new Tuple2<>(5L,1L),
new Tuple2<>(6L,1L),
new Tuple2<>(7L,7L),
new Tuple2<>(8L,7L),
new Tuple2<>(9L,7L)
);
// check program result
assertEquals(expectedResult, result);
// check aggregators
long[] aggr_values = MinimumIdFilterCounting.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
assertEquals(3, aggr_values[0]);
assertEquals(4, aggr_values[1]);
assertEquals(5, aggr_values[2]);
assertEquals(6, aggr_values[3]);
}
// ------------------------------------------------------------------------
// Test Functions
// ------------------------------------------------------------------------
public static final class NeighborWithComponentIDJoin extends RichJoinFunction<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) {
vertexWithCompId.f0 = edge.f1;
return vertexWithCompId;
}
}
public static class MinimumIdFilter extends RichFlatMapFunction<Tuple2<Tuple2<Long, Long>, Tuple2<Long, Long>>, Tuple2<Long, Long>> {
private final String aggName;
private LongSumAggregator aggr;
public MinimumIdFilter(String aggName) {
this.aggName = aggName;
}
@Override
public void open(Configuration conf) {
aggr = getIterationRuntimeContext().getIterationAggregator(aggName);
}
@Override
public void flatMap(
Tuple2<Tuple2<Long, Long>, Tuple2<Long, Long>> vertexWithNewAndOldId,
Collector<Tuple2<Long, Long>> out) {
if (vertexWithNewAndOldId.f0.f1 < vertexWithNewAndOldId.f1.f1) {
out.collect(vertexWithNewAndOldId.f0);
aggr.aggregate(1l);
}
else {
out.collect(vertexWithNewAndOldId.f1);
}
}
}
public static final class MinimumIdFilterCounting
extends RichFlatMapFunction<Tuple2<Tuple2<Long, Long>, Tuple2<Long, Long>>, Tuple2<Long, Long>> {
private static final long[] aggr_value = new long[5];
private final String aggName;
private LongSumAggregatorWithParameter aggr;
public MinimumIdFilterCounting(String aggName) {
this.aggName = aggName;
}
@Override
public void open(Configuration conf) {
final int superstep = getIterationRuntimeContext().getSuperstepNumber();
aggr = getIterationRuntimeContext().getIterationAggregator(aggName);
if (superstep > 1 && getIterationRuntimeContext().getIndexOfThisSubtask() == 0) {
LongValue val = getIterationRuntimeContext().getPreviousIterationAggregate(aggName);
aggr_value[superstep - 2] = val.getValue();
}
}
@Override
public void flatMap(
Tuple2<Tuple2<Long, Long>, Tuple2<Long, Long>> vertexWithNewAndOldId,
Collector<Tuple2<Long, Long>> out) {
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 Convergence Criterion with one parameter */
public static class UpdatedElementsConvergenceCriterion implements ConvergenceCriterion<LongValue> {
private final long threshold;
public UpdatedElementsConvergenceCriterion(long u_threshold) {
this.threshold = u_threshold;
}
@Override
public boolean isConverged(int iteration, LongValue value) {
return value.getValue() < this.threshold;
}
}
public static final class LongSumAggregatorWithParameter extends LongSumAggregator {
private long componentId;
public LongSumAggregatorWithParameter(long compId) {
this.componentId = compId;
}
public long getComponentId() {
return this.componentId;
}
}
}