Delayed message in RabbitMQ

Question

Is it possible to send message via RabbitMQ with some delay? For example I want to expire client session after 30 minutes, and I send a message which will be processed after

Answer 1

As I don't have enough reputation to add comment, posting a new answer. This is just an addition to what has been already discussed at http://www.javacodegeeks.com/2012/04/rabbitmq-scheduled-message-delivery.html

Except instead of setting ttl on messages, you can set it at queue level. Also you can avoid creating a new exchange just for the sake of redirecting the messages to different Queue. Here is sample Java code:

Producer:

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import java.util.HashMap;
import java.util.Map;

public class DelayedProducer {
    private final static String QUEUE_NAME = "ParkingQueue";
    private final static String DESTINATION_QUEUE_NAME = "DestinationQueue";

    public static void main(String[] args) throws Exception{
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setHost("localhost");
        Connection connection = connectionFactory.newConnection();
        Channel channel = connection.createChannel();

        Map arguments = new HashMap();
        arguments.put("x-message-ttl", 10000);
        arguments.put("x-dead-letter-exchange", "");
        arguments.put("x-dead-letter-routing-key", DESTINATION_QUEUE_NAME );
        channel.queueDeclare(QUEUE_NAME, false, false, false, arguments);

        for (int i=0; i<5; i++) {
            String message = "This is a sample message " + i;
            channel.basicPublish("", QUEUE_NAME, null, message.getBytes());
            System.out.println("message "+i+" got published to the queue!");
            Thread.sleep(3000);
        }

        channel.close();
        connection.close();
    }
}

Consumer:

import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.QueueingConsumer;

public class Consumer {
   private final static String DESTINATION_QUEUE_NAME = "DestinationQueue";

    public static void main(String[] args) throws Exception{
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();

        channel.queueDeclare(QUEUE_NAME, false, false, false, null);
        System.out.println(" [*] Waiting for messages. To exit press CTRL+C");

        QueueingConsumer consumer = new QueueingConsumer(channel);
        boolean autoAck = false;
        channel.basicConsume(DESTINATION_QUEUE_NAME, autoAck, consumer);

        while (true) {
            QueueingConsumer.Delivery delivery = consumer.nextDelivery();
            String message = new String(delivery.getBody());
            System.out.println(" [x] Received '" + message + "'");
            channel.basicAck(delivery.getEnvelope().getDeliveryTag(), false);
        }
    }
}