org.apache.activemq.artemis.jms.example.MultipleFailoverFailbackExample Maven / Gradle / Ivy
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* http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.activemq.artemis.jms.example;
import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.JMSException;
import javax.jms.MessageConsumer;
import javax.jms.MessageProducer;
import javax.jms.Queue;
import javax.jms.Session;
import javax.jms.TextMessage;
import javax.naming.InitialContext;
import org.apache.activemq.artemis.util.ServerUtil;
public class MultipleFailoverFailbackExample {
public static void main(final String[] args) throws Exception {
final int numMessages = 30;
Connection connection = null;
InitialContext initialContext = null;
Process[] servers = new Process[3];
try {
for (int i = 0; i < args.length; i++) {
servers[i] = ServerUtil.startServer(args[i], MultipleFailoverFailbackExample.class.getSimpleName() + i, i, 5000);
}
// Step 1. Get an initial context for looking up JNDI from the server #1
initialContext = new InitialContext();
// Step 2. Look up the JMS resources from JNDI
Queue queue = (Queue) initialContext.lookup("queue/exampleQueue");
ConnectionFactory connectionFactory = (ConnectionFactory) initialContext.lookup("ConnectionFactory");
// Step 3. Create a JMS Connection
connection = connectionFactory.createConnection();
// Step 4. Create a *non-transacted* JMS Session with client acknowledgement
Session session = connection.createSession(false, Session.CLIENT_ACKNOWLEDGE);
// Step 5. Start the connection to ensure delivery occurs
connection.start();
// Step 6. Create a JMS MessageProducer and a MessageConsumer
MessageProducer producer = session.createProducer(queue);
MessageConsumer consumer = session.createConsumer(queue);
// Step 7. Send some messages to server #1, the live server
for (int i = 0; i < numMessages; i++) {
TextMessage message = session.createTextMessage("This is text message " + i);
producer.send(message);
System.out.println("Sent message: " + message.getText());
}
// Step 8. Receive and acknowledge a third of the sent messages
TextMessage message0 = null;
for (int i = 0; i < numMessages / 3; i++) {
message0 = (TextMessage) consumer.receive(5000);
System.out.println("Got message: " + message0.getText());
}
message0.acknowledge();
// Step 9. Receive the rest third of the sent messages but *do not* acknowledge them yet
for (int i = numMessages / 3; i < numMessages; i++) {
message0 = (TextMessage) consumer.receive(5000);
System.out.println("Got message: " + message0.getText());
}
// Step 10. Crash server #1, the live server, and wait a little while to make sure
// it has really crashed
ServerUtil.killServer(servers[0]);
// Step 11. Acknowledging the 2nd half of the sent messages will fail as failover to the
// backup server has occurred
try {
message0.acknowledge();
} catch (JMSException e) {
System.err.println("Got exception while acknowledging message: " + e.getMessage());
}
// Step 12. Consume again the 2nd third of the messages again. Note that they are not considered as redelivered.
for (int i = numMessages / 3; i < (numMessages / 3) * 2; i++) {
message0 = (TextMessage) consumer.receive(5000);
System.out.printf("Got message: %s (redelivered?: %s)%n", message0.getText(), message0.getJMSRedelivered());
}
message0.acknowledge();
servers[0] = ServerUtil.startServer(args[0], MultipleFailoverFailbackExample.class.getSimpleName() + 0, 0, 5000);
// Step 11. Acknowledging the 2nd half of the sent messages will fail as failover to the
// backup server has occurred
try {
message0.acknowledge();
} catch (JMSException e) {
System.err.println("Got exception while acknowledging message: " + e.getMessage());
}
// Step 12. Consume again the 2nd third of the messages again. Note that they are not considered as redelivered.
for (int i = (numMessages / 3) * 2; i < numMessages; i++) {
message0 = (TextMessage) consumer.receive(5000);
System.out.printf("Got message: %s (redelivered?: %s)%n", message0.getText(), message0.getJMSRedelivered());
}
message0.acknowledge();
} finally {
// Step 13. Be sure to close our resources!
if (connection != null) {
connection.close();
}
if (initialContext != null) {
initialContext.close();
}
for (int i = 0; i < args.length; i++) {
ServerUtil.killServer(servers[i]);
}
}
}
}