org.apache.giraph.partition.SimpleRangePartitionFactoryTest.java Source code

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Here is the source code for org.apache.giraph.partition.SimpleRangePartitionFactoryTest.java

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/*
 * 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.giraph.partition;

import java.net.InetSocketAddress;
import java.util.ArrayList;
import java.util.Collection;

import org.apache.giraph.conf.GiraphConstants;
import org.apache.giraph.conf.ImmutableClassesGiraphConfiguration;
import org.apache.giraph.partition.PartitionOwner;
import org.apache.giraph.partition.WorkerGraphPartitioner;
import org.apache.giraph.worker.WorkerInfo;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Writable;
import org.junit.Test;

import static org.junit.Assert.assertTrue;
import static org.junit.Assert.assertEquals;

/** Test {@link org.apache.giraph.partition.SimpleLongRangePartitionerFactory}. */
public class SimpleRangePartitionFactoryTest {

    private void testRange(int numWorkers, int keySpaceSize, int allowedWorkerDiff, boolean emptyWorkers) {
        Configuration conf = new Configuration();
        conf.setLong(GiraphConstants.PARTITION_VERTEX_KEY_SPACE_SIZE, keySpaceSize);
        SimpleLongRangePartitionerFactory<Writable, Writable> factory = new SimpleLongRangePartitionerFactory<Writable, Writable>();
        factory.setConf(new ImmutableClassesGiraphConfiguration(conf));

        ArrayList<WorkerInfo> infos = new ArrayList<WorkerInfo>();
        for (int i = 0; i < numWorkers; i++) {
            WorkerInfo info = new WorkerInfo();
            info.setInetSocketAddress(new InetSocketAddress(8080));
            info.setTaskId(i);
            infos.add(info);
        }

        Collection<PartitionOwner> owners = factory.createMasterGraphPartitioner()
                .createInitialPartitionOwners(infos, -1);

        int[] tasks = new int[owners.size()];
        for (PartitionOwner owner : owners) {
            WorkerInfo worker = owner.getWorkerInfo();
            assertEquals(0, tasks[owner.getPartitionId()]);
            tasks[owner.getPartitionId()] = worker.getTaskId() + 1;
        }
        checkMapping(tasks, allowedWorkerDiff, emptyWorkers);

        WorkerGraphPartitioner<LongWritable, Writable, Writable> workerPartitioner = factory
                .createWorkerGraphPartitioner();
        workerPartitioner.updatePartitionOwners(null, owners);
        LongWritable longWritable = new LongWritable();

        int[] partitions = new int[keySpaceSize];
        for (int i = 0; i < keySpaceSize; i++) {
            longWritable.set(i);
            PartitionOwner owner = workerPartitioner.getPartitionOwner(longWritable);
            partitions[i] = owner.getPartitionId();
        }
        checkMapping(partitions, 1, emptyWorkers);
    }

    private void checkMapping(int[] mapping, int allowedDiff, boolean emptyWorkers) {
        int prev = -1;

        int max = 0;
        int min = Integer.MAX_VALUE;
        int cur = 0;
        for (int value : mapping) {
            if (value != prev) {
                if (prev != -1) {
                    min = Math.min(cur, min);
                    max = Math.max(cur, max);
                    assertTrue(prev < value);
                    if (!emptyWorkers) {
                        assertEquals(prev + 1, value);
                    }
                }
                cur = 1;
            } else {
                cur++;
            }
            prev = value;
        }
        assertTrue(min + allowedDiff >= max);
    }

    @Test
    public void testLongRangePartitionerFactory() {
        // perfect distribution
        testRange(10, 100000, 0, false);
        testRange(1000, 100000, 0, false);

        // perfect distribution even when max is hit, and max is not divisible by #workers
        testRange(8949, 100023, 0, false);
        testRange(1949, 211111, 0, false);

        // imperfect distribution - because there are more workers than max partitions.
        testRange(194942, 211111, 1, true);
    }
}