RabbitMQ 延时交换机

王小明_HIT

发布于 2019-12-04 12:18:06

1.3K0

发布于 2019-12-04 12:18:06

文章被收录于专栏：程序员奇点程序员奇点

rabbitmq_delayed_message_exchange

机制

安装插件后会生成新的Exchange类型x-delayed-message，该类型消息支持延迟投递机制,接收到消息后并未立即将消息投递至目标队列中，而是存储在mnesia(一个分布式数据系统)表中，并且当前节点是磁盘节点，那么节点重启后，消息还能保留。检测消息延迟时间，如达到可投递时间时并将其通过x-delayed-type类型标记的交换机类型投递至目标队列。但是要注意的是，如果集群中只有一个磁盘节点，如果说磁盘节点丢失，或者节点上的插件失效。意味着消息将会丢失。

特性

可通过 x-delayed-type 指定类型为 direct fanout topic 等
检测消息延迟时间，如果达到投递时间，通过x-delayed-type 标记的交换机类型进行投递。
消息存储在声明交换机的那个节点上，消息发送到延时交换机上，消息还未到发送时间，此时停机该节点，消费者不能消费此延时消息，后启动该节点，消息会被重新投递，消费者能够消费此延时消息。
磁盘节点，消息持久化，交换机持久化，消息不会丢失。

延时队列申明

Map<String,Object> map =new HashMap<>();
map.put("x-delayed-type", "direct");
channel.exchangeDeclare(exchangeName, "x-delayed-message", true, false, map);

插件安装

下载

wget https://dl.bintray.com/rabbitmq/community-plugins/3.6.x/rabbitmq_delayed_message_exchange/rabbitmq_delayed_message_exchange-20171215-3.6.x.zip

解压

下载后解压，并将其拷贝至(使用Linux Debian/RPM部署)rabbitmq服务器目录：/usr/local/rabbitmq/plugins中（windows安装目录\rabbitmq_server-version\plugins ) /usr/lib/rabbitmq/lib/rabbitmq_server-3.6.12/plugins

unzip rabbitmq_delayed_message_exchange-20171215-3.6.x.zip

启用插件

使用命令rabbitmq-plugins enable rabbitmq_delayed_message_exchang启用插件

rabbitmq-plugins enable rabbitmq_delayed_message_exchang

输出结果

The following plugins have been enabled:
rabbitmq_delayed_message_exchange

代码示例

生产者

import java.util.Date;
import java.util.HashMap;
import java.util.Map;

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


public class Producer {
    public static void main(String[] args) throws Exception {
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setVirtualHost("/");
        connectionFactory.setHost("172.31.1.135");
        connectionFactory.setUsername("xx");
        connectionFactory.setPassword("xx");
        connectionFactory.setPort(5672);
        Connection connection = connectionFactory.newConnection();
        Channel channel = connection.createChannel();
        String exchangeName = "delay-exchange";
        String routingkey = "delay.delay";

        String queueName = "delay_queueName";
        //x-delayed-message 声明
        Map<String,Object> map =new HashMap<>();
        map.put("x-delayed-type", "direct");
        channel.exchangeDeclare(exchangeName, "x-delayed-message", true, false, map);
        //注意：arguments需要声明在队列上，声明在交换机上是不会起作用的。
        channel.queueDeclare(queueName, true, false, false, map);
        channel.queueBind(queueName,exchangeName,routingkey);
        for (int i = 0; i < 3; i++) {
             // deliveryMode=2 持久化，expiration 消息有效时间
            String msg = "delayed payload".getBytes("UTF-8") +" "+new Date().getTime();
            byte[] messageBodyBytes = msg.getBytes();
            Map<String, Object> headers = new HashMap<String, Object>();
            headers.put("x-delay", 50000);
            AMQP.BasicProperties.Builder props = new AMQP.BasicProperties.Builder().headers(headers);
            channel.basicPublish(exchangeName, routingkey, props.build(), messageBodyBytes);
        }
    }
}

消费者

import java.io.IOException;
import java.util.Date;

import com.rabbitmq.client.AMQP.BasicProperties;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.DefaultConsumer;
import com.rabbitmq.client.Envelope;


public class Consumer {
    public static void main(String[] args) throws Exception {
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setVirtualHost("/");
        connectionFactory.setHost("172.31.1.135");
        connectionFactory.setPort(5672);
        connectionFactory.setUsername("xxx");
        connectionFactory.setPassword("xxx");
        Connection connection = connectionFactory.newConnection();
        Channel channel = connection.createChannel();
        String queueName = "delay_queueName";
        channel.queueDeclare(queueName,true,false,false,null);

        channel.basicConsume(queueName, false, "myConsumer Tag", new DefaultConsumer(channel){
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, BasicProperties properties, byte[] body) throws IOException {
                  String routingKey = envelope.getRoutingKey();
                  String convernType = properties.getContentType();
                  long deliveryTag = envelope.getDeliveryTag();
                  System.out.println("routingKey:"+routingKey+",convernType:"+convernType+",deliveryTag:"+deliveryTag+",Msg body:"+new String(body)+ " "+new Date().getTime());
                  channel.basicAck(deliveryTag, false);
            }

        });
    }
}

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原始发表：2019-12-03，如有侵权请联系 cloudcommunity@tencent.com 删除

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