/**
* 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.hadoop.mapred;
import static org.junit.Assert.*;
import java.io.File;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.CountDownLatch;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.http.HttpServer;
import org.junit.Test;
public class TestJettyBugMonitor {
private final Configuration conf = new Configuration();
/**
* Test that it can detect a running Jetty selector.
*/
@Test(timeout=20000)
public void testGetJettyThreads() throws Exception {
JettyBugMonitor monitor = new JettyBugMonitor(conf);
new File(System.getProperty("build.webapps", "build/webapps") + "/test"
).mkdirs();
HttpServer server = new HttpServer("test", "0.0.0.0", 0, true);
server.start();
try {
List<Long> threads = monitor.waitForJettyThreads();
assertEquals(1, threads.size());
} finally {
server.stop();
}
}
/**
* Test that the CPU monitoring can detect a spinning
* thread.
*/
@Test(timeout=5000)
public void testMonitoring() throws Exception {
// Start a thread which sucks up CPU
BusyThread busyThread = new BusyThread();
busyThread.start();
final long tid = busyThread.getId();
// Latch which will be triggered when the jetty monitor
// wants to abort
final CountDownLatch abortLatch = new CountDownLatch(1);
conf.setLong(JettyBugMonitor.CHECK_INTERVAL_KEY, 1000);
JettyBugMonitor monitor = null;
try {
monitor = new JettyBugMonitor(conf) {
@Override
protected List<Long> waitForJettyThreads() {
return Collections.<Long>singletonList(tid);
}
@Override
protected void doAbort() {
abortLatch.countDown();
// signal abort to main thread
}
};
monitor.start();
abortLatch.await();
} finally {
busyThread.done = true;
busyThread.join();
if (monitor != null) {
monitor.shutdown();
}
}
}
private static class BusyThread extends Thread {
private volatile boolean done = false;
@Override
public void run() {
while (!done) {
// spin using up CPU
}
}
}
}