org.apache.druid.client.cache.CacheDistributionTest.java Source code

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Here is the source code for org.apache.druid.client.cache.CacheDistributionTest.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.druid.client.cache;

import com.google.common.base.Function;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterables;
import com.google.common.collect.Maps;
import com.google.common.collect.Sets;
import net.spy.memcached.DefaultHashAlgorithm;
import net.spy.memcached.HashAlgorithm;
import net.spy.memcached.KetamaNodeLocator;
import net.spy.memcached.MemcachedNode;
import net.spy.memcached.util.DefaultKetamaNodeLocatorConfiguration;
import org.apache.commons.codec.digest.DigestUtils;
import org.easymock.EasyMock;
import org.junit.BeforeClass;
import org.junit.Ignore;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;

import javax.annotation.Nullable;
import java.net.InetSocketAddress;
import java.net.SocketAddress;
import java.util.Arrays;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.atomic.AtomicLong;

@RunWith(Parameterized.class)
public class CacheDistributionTest {
    public static final int KEY_COUNT = 1_000_000;

    @Parameterized.Parameters(name = "repetitions={0}, hash={1}")
    public static Iterable<Object[]> data() {
        List<HashAlgorithm> hash = ImmutableList.of(DefaultHashAlgorithm.FNV1A_64_HASH,
                DefaultHashAlgorithm.KETAMA_HASH, MemcachedCache.MURMUR3_128);
        List<Integer> repetitions = Arrays.asList(160, 500, 1000, 2500, 5000);

        Set<List<Object>> values = Sets.cartesianProduct(Sets.newLinkedHashSet(hash),
                Sets.newLinkedHashSet(repetitions));
        return Iterables.transform(values, new Function<List<Object>, Object[]>() {
            @Nullable
            @Override
            public Object[] apply(List<Object> input) {
                return input.toArray();
            }
        });
    }

    final HashAlgorithm hash;
    final int reps;

    @BeforeClass
    public static void header() {
        System.out.printf(Locale.ENGLISH, "%25s\t%5s\t%10s\t%10s\t%10s\t%10s\t%10s\t%7s\t%5s%n", "hash", "reps",
                "node 1", "node 2", "node 3", "node 4", "node 5", "min/max", "ns");
    }

    public CacheDistributionTest(final HashAlgorithm hash, final int reps) {
        this.hash = hash;
        this.reps = reps;
    }

    // Run to get a sense of cache key distribution for different ketama reps / hash functions
    // This test is disabled by default because it's a qualitative test not an unit test and thus it have a meaning only
    // when being run and checked by humans.
    @Ignore
    @Test
    public void testDistribution() {
        KetamaNodeLocator locator = new KetamaNodeLocator(ImmutableList.of(dummyNode("druid-cache.0001", 11211),
                dummyNode("druid-cache.0002", 11211), dummyNode("druid-cache.0003", 11211),
                dummyNode("druid-cache.0004", 11211), dummyNode("druid-cache.0005", 11211)), hash,
                new DefaultKetamaNodeLocatorConfiguration() {
                    @Override
                    public int getNodeRepetitions() {
                        return reps;
                    }
                });

        Map<MemcachedNode, AtomicLong> counter = Maps.newHashMap();
        long t = 0;
        for (int i = 0; i < KEY_COUNT; ++i) {
            final String k = DigestUtils.sha1Hex("abc" + i) + ":" + DigestUtils.sha1Hex("xyz" + i);
            long t0 = System.nanoTime();
            MemcachedNode node = locator.getPrimary(k);
            t += System.nanoTime() - t0;
            if (counter.containsKey(node)) {
                counter.get(node).incrementAndGet();
            } else {
                counter.put(node, new AtomicLong(1));
            }
        }

        long min = Long.MAX_VALUE;
        long max = 0;
        System.out.printf(Locale.ENGLISH, "%25s\t%5d\t", hash, reps);
        for (AtomicLong count : counter.values()) {
            System.out.printf(Locale.ENGLISH, "%10d\t", count.get());
            min = Math.min(min, count.get());
            max = Math.max(max, count.get());
        }
        System.out.printf(Locale.ENGLISH, "%7.2f\t%5.0f%n", (double) min / (double) max, (double) t / KEY_COUNT);
    }

    private static MemcachedNode dummyNode(String host, int port) {
        SocketAddress address = InetSocketAddress.createUnresolved(host, port);
        MemcachedNode node = EasyMock.createNiceMock(MemcachedNode.class);
        EasyMock.expect(node.getSocketAddress()).andReturn(address).anyTimes();
        EasyMock.replay(node);
        return node;
    }
}