/*
* 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.zookeeper.recipes.leader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import junit.framework.Assert;
import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.ZooDefs;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.test.ClientBase;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class LeaderElectionSupportTest extends ClientBase {
private static final Logger logger = LoggerFactory
.getLogger(LeaderElectionSupportTest.class);
private static final String testRootNode = "/" + System.currentTimeMillis()
+ "_";
private ZooKeeper zooKeeper;
@Before
public void setUp() throws Exception {
super.setUp();
zooKeeper = createClient();
zooKeeper.create(testRootNode + Thread.currentThread().getId(),
new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
}
@After
public void tearDown() throws Exception {
if (zooKeeper != null) {
zooKeeper.delete(testRootNode + Thread.currentThread().getId(), -1);
}
super.tearDown();
}
@Test
public void testNode() throws IOException, InterruptedException,
KeeperException {
LeaderElectionSupport electionSupport = createLeaderElectionSupport();
electionSupport.start();
Thread.sleep(3000);
electionSupport.stop();
}
@Test
public void testNodes3() throws IOException, InterruptedException,
KeeperException {
int testIterations = 3;
final CountDownLatch latch = new CountDownLatch(testIterations);
final AtomicInteger failureCounter = new AtomicInteger();
for (int i = 0; i < testIterations; i++) {
runElectionSupportThread(latch, failureCounter);
}
Assert.assertEquals(0, failureCounter.get());
if (!latch.await(10, TimeUnit.SECONDS)) {
logger
.info(
"Waited for all threads to start, but timed out. We had {} failures.",
failureCounter);
}
}
@Test
public void testNodes9() throws IOException, InterruptedException,
KeeperException {
int testIterations = 9;
final CountDownLatch latch = new CountDownLatch(testIterations);
final AtomicInteger failureCounter = new AtomicInteger();
for (int i = 0; i < testIterations; i++) {
runElectionSupportThread(latch, failureCounter);
}
Assert.assertEquals(0, failureCounter.get());
if (!latch.await(10, TimeUnit.SECONDS)) {
logger
.info(
"Waited for all threads to start, but timed out. We had {} failures.",
failureCounter);
}
}
@Test
public void testNodes20() throws IOException, InterruptedException,
KeeperException {
int testIterations = 20;
final CountDownLatch latch = new CountDownLatch(testIterations);
final AtomicInteger failureCounter = new AtomicInteger();
for (int i = 0; i < testIterations; i++) {
runElectionSupportThread(latch, failureCounter);
}
Assert.assertEquals(0, failureCounter.get());
if (!latch.await(10, TimeUnit.SECONDS)) {
logger
.info(
"Waited for all threads to start, but timed out. We had {} failures.",
failureCounter);
}
}
@Test
public void testNodes100() throws IOException, InterruptedException,
KeeperException {
int testIterations = 100;
final CountDownLatch latch = new CountDownLatch(testIterations);
final AtomicInteger failureCounter = new AtomicInteger();
for (int i = 0; i < testIterations; i++) {
runElectionSupportThread(latch, failureCounter);
}
Assert.assertEquals(0, failureCounter.get());
if (!latch.await(20, TimeUnit.SECONDS)) {
logger
.info(
"Waited for all threads to start, but timed out. We had {} failures.",
failureCounter);
}
}
@Test
public void testOfferShuffle() throws InterruptedException {
int testIterations = 10;
final CountDownLatch latch = new CountDownLatch(testIterations);
final AtomicInteger failureCounter = new AtomicInteger();
List<Thread> threads = new ArrayList<Thread>(testIterations);
for (int i = 1; i <= testIterations; i++) {
threads.add(runElectionSupportThread(latch, failureCounter,
Math.min(i * 1200, 10000)));
}
if (!latch.await(60, TimeUnit.SECONDS)) {
logger
.info(
"Waited for all threads to start, but timed out. We had {} failures.",
failureCounter);
}
}
@Test
public void testGetLeaderHostName() throws KeeperException,
InterruptedException {
LeaderElectionSupport electionSupport = createLeaderElectionSupport();
electionSupport.start();
// Sketchy: We assume there will be a leader (probably us) in 3 seconds.
Thread.sleep(3000);
String leaderHostName = electionSupport.getLeaderHostName();
Assert.assertNotNull(leaderHostName);
Assert.assertEquals("foohost", leaderHostName);
electionSupport.stop();
}
private LeaderElectionSupport createLeaderElectionSupport() {
LeaderElectionSupport electionSupport = new LeaderElectionSupport();
electionSupport.setZooKeeper(zooKeeper);
electionSupport.setRootNodeName(testRootNode
+ Thread.currentThread().getId());
electionSupport.setHostName("foohost");
return electionSupport;
}
private Thread runElectionSupportThread(final CountDownLatch latch,
final AtomicInteger failureCounter) {
return runElectionSupportThread(latch, failureCounter, 3000);
}
private Thread runElectionSupportThread(final CountDownLatch latch,
final AtomicInteger failureCounter, final long sleepDuration) {
final LeaderElectionSupport electionSupport = createLeaderElectionSupport();
Thread t = new Thread() {
@Override
public void run() {
try {
electionSupport.start();
Thread.sleep(sleepDuration);
electionSupport.stop();
latch.countDown();
} catch (Exception e) {
logger.warn("Failed to run leader election due to: {}",
e.getMessage());
failureCounter.incrementAndGet();
}
}
};
t.start();
return t;
}
}