com.greplin.zookeeper.RobustZooKeeperTest.java Source code

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Here is the source code for com.greplin.zookeeper.RobustZooKeeperTest.java

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/*
 * Copyright 2010 The Greplin Zookeeper Utility Authors.
 *
 * Licensed 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 com.greplin.zookeeper;

import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.server.quorum.QuorumPeerConfig;
import org.junit.After;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;

import java.io.IOException;
import java.util.List;
import java.util.Random;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * Test our zookeeper client (and the utilities it has).
 */
public class RobustZooKeeperTest {

    private static final int ZK_PORT = 29980;
    private static final Random RANDOM = new Random();

    private EmbeddedZookeeperServer zookeeperServer;
    private RobustZooKeeper rbz;

    @Before
    public void setup() throws QuorumPeerConfig.ConfigException, IOException {
        zookeeperServer = EmbeddedZookeeperServer.builder().clientPort(ZK_PORT).build();
        rbz = new RobustZooKeeper("localhost:" + ZK_PORT);
    }

    @After
    public void tearDown() throws InterruptedException {
        zookeeperServer.shutdown();
        rbz.shutdown();
    }

    private void checkNoRemainingLocks(String lockName) throws IOException, InterruptedException, KeeperException {
        ZooKeeper verifier = new ZooKeeper("localhost:" + ZK_PORT, Integer.MAX_VALUE, new Watcher() {
            @Override
            public void process(WatchedEvent event) {
                // no-op watcher
            }
        });
        List<String> children = verifier.getChildren(RobustZooKeeper.LOCK_NODE_PREFIX + lockName, false);
        Assert.assertEquals(0, children.size());
    }

    @Test
    public void testLockBasic() throws IOException, InterruptedException, KeeperException {
        final AtomicInteger lockCounter = new AtomicInteger(0);

        rbz.withLock("testLock", new Runnable() {
            @Override
            public void run() {
                lockCounter.incrementAndGet();
            }
        });

        Thread.sleep(200);

        Assert.assertEquals(1, lockCounter.get());

        checkNoRemainingLocks("testLock");
    }

    @Test
    public void testSingleClientLockContention() throws IOException, InterruptedException, KeeperException {
        final AtomicInteger withLockRuns = new AtomicInteger(0);
        final AtomicInteger currentWithLockRuns = new AtomicInteger(0);

        for (int i = 0; i < 10; i++) {
            rbz.withLock("testLock", new Runnable() {
                @Override
                public void run() {
                    withLockRuns.incrementAndGet();
                    int currentlyRunning = currentWithLockRuns.incrementAndGet();
                    Assert.assertEquals(1, currentlyRunning);
                    try {
                        Thread.sleep(RANDOM.nextInt(100));
                    } catch (InterruptedException e) {
                        throw new RuntimeException(e);
                    }
                    currentlyRunning = currentWithLockRuns.decrementAndGet();
                    Assert.assertEquals(0, currentlyRunning);
                }
            });
        }

        Thread.sleep(1000);

        Assert.assertEquals(10, withLockRuns.get());
        Assert.assertEquals(0, currentWithLockRuns.get());

        checkNoRemainingLocks("testLock");
    }

    @Test
    public void testMultiClientLockContention() throws IOException, InterruptedException, KeeperException {
        final AtomicInteger withLockRuns = new AtomicInteger(0);
        final AtomicInteger currentWithLockRuns = new AtomicInteger(0);

        for (int i = 0; i < 5; i++) {
            RobustZooKeeper zk = new RobustZooKeeper("localhost:" + ZK_PORT);
            zk.withLock("testLock", new Runnable() {
                @Override
                public void run() {
                    withLockRuns.incrementAndGet();
                    int currentlyRunning = currentWithLockRuns.incrementAndGet();
                    Assert.assertEquals(1, currentlyRunning);
                    try {
                        Thread.sleep(RANDOM.nextInt(100));
                    } catch (InterruptedException e) {
                        throw new RuntimeException(e);
                    }
                    currentlyRunning = currentWithLockRuns.decrementAndGet();
                    Assert.assertEquals(0, currentlyRunning);
                }
            });
        }

        Thread.sleep(1000);

        Assert.assertEquals(5, withLockRuns.get());
        Assert.assertEquals(0, currentWithLockRuns.get());

        checkNoRemainingLocks("testLock");
    }

    @Test
    public void testLockWithClientFailure() throws IOException, InterruptedException, KeeperException {
        final AtomicInteger withLockRuns = new AtomicInteger(0);
        final AtomicInteger currentWithLockRuns = new AtomicInteger(0);

        for (int i = 0; i < 5; i++) {
            final RobustZooKeeper zk = new RobustZooKeeper("localhost:" + ZK_PORT);

            if (i == 0) {
                // client 0 fails while holding the lock
                zk.withLock("testLock", new Runnable() {
                    @Override
                    public void run() {
                        withLockRuns.incrementAndGet();
                        try {
                            zk.getClient().close(); // NEVER do this for real - but it's a reasonable way to simulate a failure
                        } catch (InterruptedException e) {
                            Assert.fail();
                        } catch (IOException e) {
                            Assert.fail();
                        }
                    }
                });

            } else {
                zk.withLock("testLock", new Runnable() {
                    @Override
                    public void run() {
                        withLockRuns.incrementAndGet();
                        int currentlyRunning = currentWithLockRuns.incrementAndGet();
                        Assert.assertEquals(1, currentlyRunning);
                        try {
                            Thread.sleep(RANDOM.nextInt(100));
                        } catch (InterruptedException e) {
                            throw new RuntimeException(e);
                        }
                        currentlyRunning = currentWithLockRuns.decrementAndGet();
                        Assert.assertEquals(0, currentlyRunning);
                    }
                });
            }
        }

        Thread.sleep(1000);

        Assert.assertEquals(5, withLockRuns.get());
        Assert.assertEquals(0, currentWithLockRuns.get());

        checkNoRemainingLocks("testLock");
    }
}