Java example source code file (MultiMonitorTest.java)

This example Java source code file (MultiMonitorTest.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

countermonitormbean, countlistener, different_string, gaugemonitormbean, management, mbeanserverinvocationhandler, monitored, objectname, over_counter_threshold, over_gauge_threshold, random, string, string_to_compare, stringmonitormbean, util

The MultiMonitorTest.java Java example source code

/*
 * Copyright (c) 2004, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/*
 * @test
 * @bug 4984057
 * @summary Test that monitors can sample a large number of attributes
 * @author Eamonn McManus
 * @run clean MultiMonitorTest
 * @run build MultiMonitorTest
 * @run main MultiMonitorTest
 */

import java.util.*;
import javax.management.*;
import javax.management.monitor.*;

/* We create N MBeans and three monitors, one for each different
   monitor type.  Each monitor monitors a single attribute in each of
   the N MBeans.  We arrange for the trigger condition to be
   satisfied, so the listener we register on each monitor should get N
   notifications.  */
public class MultiMonitorTest {
    static final int N = 100;
    static final ObjectName[] mbeanNames = new ObjectName[N];
    static final Monitored[] monitored = new Monitored[N];
    static final int COUNTER_THRESHOLD = 1000;
    static final int OVER_COUNTER_THRESHOLD = 2000;
    static final double GAUGE_THRESHOLD = 1000.0;
    static final double OVER_GAUGE_THRESHOLD = 2000.0;
    static final String STRING_TO_COMPARE = "chou";
    static final String DIFFERENT_STRING = "chevre";

    public static void main(String[] args) throws Exception {
        System.out.println("Test that monitors can sample a large " +
                           "number of attributes");

        final MBeanServer mbs = MBeanServerFactory.createMBeanServer();
        for (int i = 0; i < N; i++) {
            mbeanNames[i] = new ObjectName(":type=Monitored,instance=" + i);
            monitored[i] = new Monitored();
            mbs.registerMBean(monitored[i], mbeanNames[i]);
        }
        final ObjectName counterMonitor =
            new ObjectName(":type=CounterMonitor");
        final ObjectName gaugeMonitor =
            new ObjectName(":type=GaugeMonitor");
        final ObjectName stringMonitor =
            new ObjectName(":type=StringMonitor");
        final ObjectName[] monitorNames =
            new ObjectName[] {counterMonitor, gaugeMonitor, stringMonitor};
        final String[] attrNames =
            new String[] {"CounterValue", "GaugeValue", "StringValue"};
        mbs.createMBean(CounterMonitor.class.getName(), counterMonitor);
        mbs.createMBean(GaugeMonitor.class.getName(), gaugeMonitor);
        mbs.createMBean(StringMonitor.class.getName(), stringMonitor);
        final CounterMonitorMBean counterProxy = (CounterMonitorMBean)
            MBeanServerInvocationHandler
            .newProxyInstance(mbs, counterMonitor, CounterMonitorMBean.class,
                              false);
        final GaugeMonitorMBean gaugeProxy = (GaugeMonitorMBean)
            MBeanServerInvocationHandler
            .newProxyInstance(mbs, gaugeMonitor, GaugeMonitorMBean.class,
                              false);
        final StringMonitorMBean stringProxy = (StringMonitorMBean)
            MBeanServerInvocationHandler
            .newProxyInstance(mbs, stringMonitor, StringMonitorMBean.class,
                              false);
        final MonitorMBean[] proxies = new MonitorMBean[] {
            counterProxy, gaugeProxy, stringProxy,
        };
        for (int i = 0; i < 3; i++) {
            proxies[i].setGranularityPeriod(1);
            proxies[i].setObservedAttribute(attrNames[i]);
            for (int j = 0; j < N; j++)
                proxies[i].addObservedObject(mbeanNames[j]);
        }

        final CountListener[] listeners = new CountListener[] {
            new CountListener(), new CountListener(), new CountListener()
        };
        for (int i = 0; i < 3; i++) {
            mbs.addNotificationListener(monitorNames[i], listeners[i],
                                        null, null);
        }

        counterProxy.setInitThreshold(new Integer(COUNTER_THRESHOLD));
        counterProxy.setNotify(true);
        gaugeProxy.setThresholds(new Double(GAUGE_THRESHOLD), new Double(0.0));
        gaugeProxy.setNotifyHigh(true);
        stringProxy.setStringToCompare(STRING_TO_COMPARE);
        stringProxy.setNotifyDiffer(true);

        // A couple of granularity periods to detect bad behaviour
        Thread.sleep(2);

        if (!listenersAreAll(0, listeners)) {
            System.out.println("TEST FAILED: listeners not all 0");
            System.exit(1);
        }

        for (int i = 0; i < 3; i++)
            proxies[i].start();

        long startTime = System.currentTimeMillis();
        while (!listenersAreAll(N, listeners)
               && System.currentTimeMillis() < startTime + 5000)
            Thread.sleep(1);

        // More time for bad behaviour
        Thread.sleep(1000);

        if (!listenersAreAll(N, listeners)) {
            System.out.print("TEST FAILED: listener counts wrong:");
            for (int i = 0; i < listeners.length; i++)
                System.out.print(" " + listeners[i].getCount());
            System.out.println();
            System.exit(1);
        }

        for (int i = 0; i < 3; i++) {
            proxies[i].stop();
            for (int j = 0; j < N; j++)
                proxies[i].removeObservedObject(mbeanNames[j]);
            ObjectName[] observed = proxies[i].getObservedObjects();
            if (observed.length != 0) {
                System.out.println("TEST FAILED: not all observed objects " +
                                   "removed: " + Arrays.asList(observed));
                System.exit(1);
            }
        }

        System.out.println("Test passed");
    }

    public static interface MonitoredMBean {
        public int getCounterValue();
        public double getGaugeValue();
        public String getStringValue();
    }

    public static class Monitored implements MonitoredMBean {
        /* We give a small random number of normal readings (possibly
           zero) before giving a reading that provokes a
           notification.  */
        private int okCounter = randomInt(5);
        private int okGauge = randomInt(5);
        private int okString = randomInt(5);

        public synchronized int getCounterValue() {
            if (--okCounter >= 0)
                return 0;
            else
                return OVER_COUNTER_THRESHOLD;
        }

        public synchronized double getGaugeValue() {
            if (--okGauge >= 0)
                return 0.0;
            else
                return OVER_GAUGE_THRESHOLD;
        }

        public synchronized String getStringValue() {
            if (--okString >= 0)
                return STRING_TO_COMPARE;
            else
                return DIFFERENT_STRING;
        }
    }

    public static class CountListener implements NotificationListener {
        private int count;

        public synchronized void handleNotification(Notification n, Object h) {
            if (!(n instanceof MonitorNotification)) {
                System.out.println("TEST FAILED: bad notif: " +
                                   n.getClass().getName());
                System.exit(1);
            }
            if (n.getType().indexOf("error") >= 0) {
                System.out.println("TEST FAILED: error notif: " + n.getType());
                System.exit(1);
            }
            count++;
        }

        public synchronized int getCount() {
            return count;
        }
    }

    private static boolean listenersAreAll(int n, CountListener[] listeners) {
        for (int i = 0; i < listeners.length; i++) {
            if (listeners[i].getCount() != n)
                return false;
        }
        return true;
    }

    private static final Random random = new Random();
    static synchronized int randomInt(int n) {
        return random.nextInt(n);
    }
}