Uniform Distributed Destinations (UDD) feature in WebLogic

The below post depicts a sample configuration of a Uniform Distributed Destination (Queue/ Topic) for the WebLogic JMS feature.

A Distributed Destination represents a group of physical queues, or topics, whose members are hosted by JMS servers in a WebLogic cluster. The distributed destination is bound to a logical JNDI name in the cluster-wide JNDI tree. Applications that use a distributed destination are more highly available than applications that use standalone destinations because it provides.

1.Load balancing

2.Failover for the members of a distributed destination in a cluster.

Pre-requisites:

1. A cluster configured with at least 2 managed servers.
2. A persistent store configured for each of the managed server in the cluster.

Steps:

1. Create two JMS Servers and target each one to the migratable servers in the cluster.

a. Login into the Admin Console  –> Navigate to Messaging  –> JMS Servers in the left panel, click new.

b. Create the JMS Server and associate it with the Migratable managed servers of the cluster.

Target each JMS Server to an individual Migratable Managed server.

Note: You need to specify the Persistent store for the JMS Server if it is targeted to a Migratable Server.

You can use the below WLST script to create a FileStore.

from java.util import *

from javax.management import *

import javax.management.Attribute

print 'starting the script ....'

username = 'weblogic'

password = 'weblogic'

AdminURL= 't3://localhost:8001'

connect(username,password,AdminURL)

edit()

startEdit()

cd('/')

cmo.createFileStore('FileStore-0')

cd('/FileStores/FileStore-0')

cmo.setDirectory('G:\BEA103\user_projects\domains\Wonders_Domain')

set('Targets',jarray.array([ObjectName('com.bea:Name=MS1 (migratable),Type=MigratableTarget')], ObjectName))

activate()

Alternatively you can configure the FileStores from the Admin Console as well.

Refer the below link for further info.

http://download.oracle.com/docs/cd/E12840_01/wls/docs103/config_wls/store.html#wp1142183

c. Similarly create another JMS  Server and target it to the other managed server in the cluster.

2. Create a JMS Module.

a. Create a JMS Module and target it to the cluster.

3. Create a Sub Deployment.

a. Click on the newly created JMS Module and you will see the ‘SubDeployment’ tab.

b. Click on ‘new’ to create a new Sub Deployment.

c. Target the sub deployment to the two  JMS Servers.

4. Create JMS Resources. (Connection Factory and JMS Destinations).

a. Create a JMS Connection Factory.

b.  Target the Connection Factory to set of JMS Servers created.

5. Create the Distributed Destination (Either Queue or Topic).

a. From the JMS Module page, create a Distributed Queue.

NOTE:  Make sure you enable the “Allocate Members Uniformly” tag to setup Uniform Distributed Queue.

For more details refer the below link.

http://download.oracle.com/docs/cd/E11035_01/wls100/jms_admin/advance_config.html#wp1067272

b. Specify the Sub Deployment and target it to the set of JMS Servers created.

This completes the Uniform Distributed Destination (UDD) configuration.

6. Test the setup.

a.  Compile and execute the below QueueSend.java program.

*******************************************************

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Hashtable;
import javax.jms.*;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
public class QueueSend
{
public final static String JNDI_FACTORY="weblogic.jndi.WLInitialContextFactory";
public final static String JMS_FACTORY="CF1";
public final static String QUEUE="DistributedQueue";
private QueueConnectionFactory qconFactory;
private QueueConnection qcon;
private QueueSession qsession;
private QueueSender qsender;
private Queue queue;
private TextMessage msg;
public void init(Context ctx, String queueName)
throws NamingException, JMSException
{
qconFactory = (QueueConnectionFactory) ctx.lookup(JMS_FACTORY);
qcon = qconFactory.createQueueConnection();
qsession = qcon.createQueueSession(false, Session.AUTO_ACKNOWLEDGE);
queue = (Queue) ctx.lookup(queueName);
qsender = qsession.createSender(queue);
msg = qsession.createTextMessage();
qcon.start();
}
public void send(String message) throws JMSException {
msg.setText(message);
qsender.send(msg);
}
public void close() throws JMSException {
qsender.close();
qsession.close();
qcon.close();
}
public static void main(String[] args) throws Exception {
if (args.length != 1) {
System.out.println("Usage: java examples.jms.queue.QueueSend WebLogicURL");
return;
}
InitialContext ic = getInitialContext(args[0]);
QueueSend qs = new QueueSend();
qs.init(ic, QUEUE);
readAndSend(qs);
qs.close();
}
private static void readAndSend(QueueSend qs)
throws IOException, JMSException
{
BufferedReader msgStream = new BufferedReader(new InputStreamReader(System.in));
String line=null;
boolean quitNow = false;
do {
System.out.print("Enter message ("quit" to quit): n");
line = msgStream.readLine();
if (line != null && line.trim().length() != 0) {
qs.send(line);
System.out.println("JMS Message Sent: "+line+"n");
quitNow = line.equalsIgnoreCase("quit");
}
} while (! quitNow);
}
private static InitialContext getInitialContext(String url)
throws NamingException
{
Hashtable<String,String> env = new Hashtable<String,String>();
env.put(Context.INITIAL_CONTEXT_FACTORY, JNDI_FACTORY);
env.put(Context.PROVIDER_URL, url);
return new InitialContext(env);
}
}

*******************************************************

NOTE: We are sending messages to the url of first managed server in the cluster

b. Compile and execute the below QueueReceive.java program.

*******************************************************

import java.util.Hashtable;
import javax.jms.*;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
public class QueueReceive implements MessageListener
{
public final static String JNDI_FACTORY="weblogic.jndi.WLInitialContextFactory";
public final static String JMS_FACTORY="CF1";
public final static String QUEUE="DistributedQueue";
private QueueConnectionFactory qconFactory;
private QueueConnection qcon;
private QueueSession qsession;
private QueueReceiver qreceiver;
private Queue queue;
private boolean quit = false;

public void onMessage(Message msg)
{
try {
String msgText;
if (msg instanceof TextMessage) {
msgText = ((TextMessage)msg).getText();
} else {
msgText = msg.toString();
}
System.out.println("Message Received: "+ msgText );

if (msgText.equalsIgnoreCase("quit")) {
synchronized(this) {
quit = true;
this.notifyAll(); // Notify main thread to quit
}
}
}
catch (JMSException jmse) {
System.err.println("An exception occurred: "+jmse.getMessage());
}
}

public void init(Context ctx, String queueName) throws NamingException, JMSException
{
qconFactory = (QueueConnectionFactory) ctx.lookup(JMS_FACTORY);
qcon = qconFactory.createQueueConnection();
qsession = qcon.createQueueSession(false, Session.AUTO_ACKNOWLEDGE);
queue = (Queue) ctx.lookup(queueName);
qreceiver = qsession.createReceiver(queue);
qreceiver.setMessageListener(this);
qcon.start();
}

public void close()throws JMSException
{
qreceiver.close();
qsession.close();
qcon.close();
}

public static void main(String[] args) throws Exception {
if (args.length != 1) {
System.out.println("Usage: java examples.jms.queue.QueueReceive WebLogicURL");
return;
}
InitialContext ic = getInitialContext(args[0]);
QueueReceive qr = new QueueReceive();
qr.init(ic, QUEUE);
System.out.println("JMS Ready To Receive Messages (To quit, send a "quit" message).");
synchronized(qr) {
while (! qr.quit) {
try {
qr.wait();
}
catch (InterruptedException ie) {}
}
}
qr.close();
}

private static InitialContext getInitialContext(String url) throws NamingException
{
Hashtable<String,String> env = new Hashtable<String,String>();
env.put(Context.INITIAL_CONTEXT_FACTORY, JNDI_FACTORY);
env.put(Context.PROVIDER_URL, url);
return new InitialContext(env);
}
}

*******************************************************

NOTE: We are listening to the JMS messages from the URL of the second managed server in the cluster.

We  are able to read the JMS message successfully on  a different server in the cluster. 🙂

Reference:

http://download.oracle.com/docs/cd/E11035_01/wls100/jms_admin/advance_config.html#wp1079177

Regards,

Wonders Team. 🙂