The VMMetrics example is a JMS application that monitors the Java VM used by the Sun Java(tm) System Message Queue broker : Java Message Service JMS « J2EE « Java
The VMMetrics example is a JMS application that monitors the Java VM used by the Sun Java(tm) System Message Queue broker
/*
* @(#)VMMetrics.java 1.3 04/01/05
*
* Copyright (c) 2000-2003 Sun Microsystems, Inc. All Rights Reserved.
*
* Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
* modify and redistribute this software in source and binary code form,
* provided that i) this copyright notice and license appear on all copies of
* the software; and ii) Licensee does not utilize the software in a manner
* which is disparaging to Sun.
*
* This software is provided "AS IS," without a warranty of any kind. ALL
* EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
* IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
* NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
* LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
* OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
* LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
* INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
* CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
* OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGES.
*
* This software is not designed or intended for use in on-line control of
* aircraft, air traffic, aircraft navigation or aircraft communications; or in
* the design, construction, operation or maintenance of any nuclear
* facility. Licensee represents and warrants that it will not use or
* redistribute the Software for such purposes.
*/
import java.util.Enumeration;
import java.util.Properties;
import javax.jms.*;
/**
* The VMMetrics example is a JMS application that monitors the
* Java VM used by the Sun Java(tm) System Message Queue broker. It does so by
* subscribing to a topic named 'mq.metrics.jvm'. The messages that arrive
* contain Java VM information such as:
* - amount of free memory
* - amount of maximum memory
* - total amount of memory
*
* By default VMMetrics will connect to the broker running on localhost:7676.
* You can use -DimqAddressList attribute to change the host, port and
* transport:
*
* java -DimqAddressList=mq://<host>:<port>/jms VMMetrics
*/
public class VMMetrics implements MessageListener {
ConnectionFactory metricConnectionFactory;
Connection metricConnection;
Session metricSession;
MessageConsumer metricConsumer;
Topic metricTopic;
MetricsPrinter mp;
int rowsPrinted = 0;
public static void main(String args[]) {
VMMetrics bm = new VMMetrics();
bm.initPrinter();
bm.initJMS();
bm.subscribeToMetric();
}
/*
* Initializes the class that does the printing, MetricsPrinter.
* See the MetricsPrinter class for details.
*/
private void initPrinter() {
String oneRow[] = new String[ 3 ];
int i = 0;
mp = new MetricsPrinter(3, 2, "-");
i = 0;
oneRow[i++] = "Free Memory";
oneRow[i++] = "Max Memory";
oneRow[i++] = "Total Memory";
mp.addTitle(oneRow);
}
/**
* Create the Connection and Session etc.
*/
public void initJMS() {
try {
metricConnectionFactory = new com.sun.messaging.ConnectionFactory();
metricConnection = metricConnectionFactory.createConnection();
metricConnection.start();
// creating Session
// Transaction Mode: None
// Acknowledge Mode: Automatic
metricSession = metricConnection.createSession(false,
Session.AUTO_ACKNOWLEDGE);
} catch(Exception e) {
System.err.println("Cannot create metric connection or session: "
+ e.getMessage());
e.printStackTrace();
System.exit(1);
}
}
public void subscribeToMetric() {
try {
metricTopic = metricSession.createTopic("mq.metrics.jvm");
metricConsumer = metricSession.createConsumer(metricTopic);
metricConsumer.setMessageListener(this);
} catch(JMSException e) {
System.err.println("Cannot subscribe to metric topic: "
+ e.getMessage());
e.printStackTrace();
System.exit(1);
}
}
/*
* When a metric message arrives
* - verify it's type
* - extract it's fields
* - print one row of output
*/
public void onMessage(Message m) {
try {
MapMessage mapMsg = (MapMessage)m;
String type = mapMsg.getStringProperty("type");
if (type.equals("mq.metrics.jvm")) {
String oneRow[] = new String[ 3 ];
int i = 0;
/*
* Extract broke metrics
*/
oneRow[i++] = Long.toString(mapMsg.getLong("freeMemory"));
oneRow[i++] = Long.toString(mapMsg.getLong("maxMemory"));
oneRow[i++] = Long.toString(mapMsg.getLong("totalMemory"));
mp.add(oneRow);
if ((rowsPrinted % 20) == 0) {
mp.print();
} else {
mp.print(false);
}
rowsPrinted++;
mp.clear();
} else {
System.err.println("Msg received: not vm metric type");
}
} catch (Exception e) {
System.err.println("onMessage: Exception caught: " + e);
}
}
}
JMQ-monitoring.zip( 18 k)