RabbitMQ学习--死信队列
Posted 三笠·阿卡曼
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死信队列
概念
死信,指的是无法被消费的消息,字面意思可以这样理解,一般来说,producer 将消息投递到 broker 或者直接到 queue 里了,consumer 从 queue 取出消息进行消费,但某些时候由于特定的原因导致** queue 中的某些消息无法被消费**,这样的消息如果没有后续的处理,就变成了死信,有死信自然就有了死信队列。
应用场景:为了保证订单业务的消息数据不丢失,需要使用到RabbitMQ 的死信队列机制,当消息消费发生异常时,将消息投入死信队列中.还有比如说: 用户在商城下单成功并点击去支付后在指定时间未支付时自动失效
死信的来源
- 消息TTL(存活时间)过期;
- 队列达到最大长度(队列满了,无法再添加数据到mq中);
- 消息被拒绝(basic.reject或basic.nack)并且requeue=false;
死信实战
代码架构图
演示消息TTL过期导致的消息进入死信队列
生产者
package com.vleus.rabbitmq.dead_exchange;
import com.rabbitmq.client.AMQP;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.impl.AMQBasicProperties;
import com.vleus.rabbitmq.utils.RabbitMqUtils;
import java.nio.charset.StandardCharsets;
/**
* @author vleus
* @date 2021年07月24日 22:23
*
* 死信队列之生产者生产消息
*/
public class Producer
public static final String NORMAL_EXCHANGE = "normal_exchange";
public static final String NORMAL_QUEUE = "normal_queue";
public static void main(String[] args) throws Exception
Channel channel = RabbitMqUtils.getChannel();
//发送延迟消息(死信消息),设置TTL(time to live)
AMQP.BasicProperties basicProperties =
new AMQP.BasicProperties()
.builder().expiration("10000").build();
for (int i = 1; i < 11; i++)
String message = "info" + i;
channel.basicPublish(NORMAL_EXCHANGE,"zhangsan",basicProperties,message.getBytes(StandardCharsets.UTF_8));
消费者C1(消费正常队列的消息)
package com.vleus.rabbitmq.dead_exchange;
import com.rabbitmq.client.BuiltinExchangeType;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.DeliverCallback;
import com.vleus.rabbitmq.utils.RabbitMqUtils;
import java.util.HashMap;
import java.util.Map;
/**
* @author vleus
* @date 2021年07月24日 22:02
* <p>
* 死信队列实战
* 正常消费者1
*/
public class Consumer01
//定义普通交换机
public static final String NORMAL_EXCHANGE = "normal_exchange";
//死信队列交换机
public static final String DEAD_EXCHANGE = "dead_exchange";
//普通队列名称
public static final String NORMAL_QUEUE = "normal_queue";
//死信队列的名称
public static final String DEAD_QUEUE = "dead_queue";
public static void main(String[] args) throws Exception
//获取信道
Channel channel = RabbitMqUtils.getChannel();
//声明死信和普通交换机,类型为direct
channel.exchangeDeclare(NORMAL_EXCHANGE, BuiltinExchangeType.DIRECT);
channel.exchangeDeclare(DEAD_EXCHANGE, BuiltinExchangeType.DIRECT);
//声明普通队列
Map<String, Object> argumentMap = new HashMap<>();
//设置正常消息的过期时间
argumentMap.put("x-message-ttl", 10000);
//正常队列设置死信交换机是谁?
argumentMap.put("x-dead-letter-exchange", DEAD_EXCHANGE);
//设置死信routingKey
argumentMap.put("x-dead-letter-routing-key", "lisi");
//设置正常队列的队列长度的限制
// argumentMap.put("x-max-length", 6);
channel.queueDeclare(NORMAL_QUEUE, false, false, false, argumentMap);
//声明死信队列(消息是从普通队列转发到死信队列)
channel.queueDeclare(DEAD_QUEUE, false, false, false, null);
//普通交换机与普通队列的绑定
channel.queueBind(NORMAL_QUEUE, NORMAL_EXCHANGE, "zhangsan");
//死信交换机与死信队列的绑定
channel.queueBind(DEAD_QUEUE, DEAD_EXCHANGE, "lisi");
System.out.println("正常消费者C1等待接收消息");
DeliverCallback deliverCallback = (consumerTag, message) ->
System.out.println("Consumer01接收的消息为: " + new String(message.getBody(), "UTF-8"));
;
channel.basicConsume(NORMAL_QUEUE, true, deliverCallback, consumerTag ->
);
消费者C2
package com.vleus.rabbitmq.dead_exchange;
import com.rabbitmq.client.BuiltinExchangeType;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.DeliverCallback;
import com.vleus.rabbitmq.utils.RabbitMqUtils;
import java.util.HashMap;
import java.util.Map;
/**
* @author vleus
* @date 2021年07月24日 22:02
* <p>
* 死信队列实战
* 正常消费者1
*/
public class Consumer02
//死信队列的名称
public static final String DEAD_QUEUE = "dead_queue";
public static void main(String[] args) throws Exception
//获取信道
Channel channel = RabbitMqUtils.getChannel();
System.out.println("正常消费者C1等待接收消息");
DeliverCallback deliverCallback = (consumerTag, message) ->
System.out.println("Consumer02接收的消息为: " + new String(message.getBody(), "UTF-8"));
;
channel.basicConsume(DEAD_QUEUE, true, deliverCallback, consumerTag ->
);
演示消息超过正常队列长度进入死信队列
生产者
package com.vleus.rabbitmq.dead_exchange;
import com.rabbitmq.client.AMQP;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.impl.AMQBasicProperties;
import com.vleus.rabbitmq.utils.RabbitMqUtils;
import java.nio.charset.StandardCharsets;
/**
* @author vleus
* @date 2021年07月24日 22:23
*
* 死信队列之生产者生产消息
*/
public class Producer
public static final String NORMAL_EXCHANGE = "normal_exchange";
public static final String NORMAL_QUEUE = "normal_queue";
public static void main(String[] args) throws Exception
Channel channel = RabbitMqUtils.getChannel();
//发送延迟消息(死信消息),设置TTL(time to live)
// AMQP.BasicProperties basicProperties =
// new AMQP.BasicProperties()
// .builder().expiration("10000").build();
for (int i = 1; i < 11; i++)
String message = "info" + i;
channel.basicPublish(NORMAL_EXCHANGE,"zhangsan",null,message.getBytes(StandardCharsets.UTF_8));
package com.vleus.rabbitmq.dead_exchange;
import com.rabbitmq.client.BuiltinExchangeType;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.DeliverCallback;
import com.vleus.rabbitmq.utils.RabbitMqUtils;
import java.util.HashMap;
import java.util.Map;
/**
* @author vleus
* @date 2021年07月24日 22:02
* <p>
* 死信队列实战
* 正常消费者1
*/
public class Consumer01
//定义普通交换机
public static final String NORMAL_EXCHANGE = "normal_exchange";
//死信队列交换机
public static final String DEAD_EXCHANGE = "dead_exchange";
//普通队列名称
public static final String NORMAL_QUEUE = "normal_queue";
//死信队列的名称
public static final String DEAD_QUEUE = "dead_queue";
public static void main(String[] args) throws Exception
//获取信道
Channel channel = RabbitMqUtils.getChannel();
//声明死信和普通交换机,类型为direct
channel.exchangeDeclare(NORMAL_EXCHANGE, BuiltinExchangeType.DIRECT);
channel.exchangeDeclare(DEAD_EXCHANGE, BuiltinExchangeType.DIRECT);
//声明普通队列
Map<String, Object> argumentMap = new HashMap<>();
//设置正常消息的过期时间
// argumentMap.put("x-message-ttl", 10000);
//正常队列设置死信交换机是谁?
argumentMap.put("x-dead-letter-exchange", DEAD_EXCHANGE);
//设置死信routingKey
argumentMap.put("x-dead-letter-routing-key", "lisi");
//设置正常队列的队列长度的限制
argumentMap.put("x-max-length", 6);
channel.queueDeclare(NORMAL_QUEUE, false, false, false, argumentMap);
//声明死信队列(消息是从普通队列转发到死信队列)
channel.queueDeclare(DEAD_QUEUE, false, false, false, null);
//普通交换机与普通队列的绑定
channel.queueBind(NORMAL_QUEUE, NORMAL_EXCHANGE, "zhangsan");
//死信交换机与死信队列的绑定
channel.queueBind(DEAD_QUEUE, DEAD_EXCHANGE, "lisi");
System.out.println("正常消费者C1等待接收消息");
DeliverCallback deliverCallback = (consumerTag, message) ->
System.out.println("Consumer01接收的消息为: " + new String(message.getBody(), "UTF-8"));
;
channel.basicConsume(NORMAL_QUEUE, true, deliverCallback, consumerTag ->
);
消费者C2
package com.vleus.rabbitmq.dead_exchange;
import com.rabbitmq.client.BuiltinExchangeType;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.DeliverCallback;
import com.vleus.rabbitmq.utils.RabbitMqUtils;
import java.util.HashMap;
import java.util.Map;
/**
* @author vleus
* @date 2021年07月24日 22:02
* <p>
* 死信队列实战
* 正常消费者1
*/
public class Consumer02
//死信队列的名称
public static final String DEAD_QUEUE = "dead_queue";
public static void main(String[] args) throws Exception
//获取信道
Channel channel = RabbitMqUtils.getChannel();
System.out.println("正常消费者C1等待接收消息");
DeliverCallback deliverCallback = (consumerTag, message) ->
System.out.println("Consumer02接收的消息为: " + new String(message.getBody(), "UTF-8"));
;
channel.basicConsume(DEAD_QUEUE, true, deliverCallback, consumerTag ->
);
演示消息被拒绝进入死信队列
package com.vleus.rabbitmq.dead_exchange;
import com.rabbitmq.client.AMQP;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.impl.AMQBasicProperties;
import com.vleus.rabbitmq.utils.RabbitMqUtils;
import java.nio.charset.StandardCharsets;
/**
* @author vleus
* @date 2021年07月24日 22:23
*
* 死信队列之生产者生产消息
*/
public class Producer
public static final String NORMAL_EXCHANGE = "normal_exchange";
public static final String NORMAL_QUEUE = "normal_queue";
public static void main(String[] args) throws Exception
Channel channel = RabbitMqUtils.getChannel();
//发送延迟消息(死信消息),设置TTL(time to live)
// AMQP.BasicProperties basicProperties =
// new AMQP.BasicProperties()
// .builder().expiration("10000").build();
for (int i = 1; i < 11; i++)
String message = "info" + i;
channel.basicPublish(NORMAL_EXCHANGE,"zhangsan",null,message.getBytes(StandardCharsets.UTF_8));
消费者C1
package com.vleus.rabbitmq.dead_exchange;
import com.rabbitmq.client.BuiltinExchangeType;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.DeliverCallback;
import com.vleus.rabbitmq.utils.RabbitMqUtils;
import java.util.HashMap;
import java.util.Map;
/**
* @author vleus
* @date 2021年07月24日 22:02
* <p>
* 死信队列实战
* 正常消费者1
*/
public class Consumer01
//定义普通交换机
public static final String NORMAL_EXCHANGE = "normal_exchange";
//死信队列交换机
public static final String DEAD_EXCHANGE = "dead_exchange";
//普通队列名称
public static final String NORMAL_QUEUE = "normal_queue";
//死信队列的名称
public static final String DEAD_QUEUE = "dead_queue";
public static void main(String[] args) throws Exception
//获取信道
Channel channel = RabbitMqUtils.getChannel();
//声明死信和普通交换机,类型为direct
channel.exchangeDeclare(NORMAL_EXCHANGE, BuiltinExchangeType.DIRECT);
channel.exchangeDeclare(DEAD_EXCHANGE, BuiltinExchangeType.DIRECT);
//声明普通队列
Map<String, Object> argumentMap = new HashMap<>();
//设置正常消息的过期时间
// argumentMap.put("x-message-ttl", 10000);
//正常队列设置死信交换机是谁?
argumentMap.put("x-dead-letter-exchange", DEAD_EXCHANGE);
//设置死信routingKey
argumentMap.put("x-dead-letter-routing-key", "lisi");
//设置正常队列的队列长度的限制
// argumentMap.put("x-max-length", 6);
channel.queueDeclare(NORMAL_QUEUE, false, false, false, argumentMap);
//声明死信队列(消息是从普通队列转发到死信队列)
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