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RocketMQ

本文主要是介绍RocketMQ，对大家解决编程问题具有一定的参考价值，需要的程序猿们随着小编来一起学习吧！

RocketMQ概述

RocketMQ 是一款分布式、队列模型的消息中间件，具有以下特点： 能够保证严格的消息顺序 提供丰富的消息拉取模式 高效的订阅者水平扩展能力 实时的消息订阅机制 亿级消息堆积能力

RocketMQ包含的组件

NameServer：单点，供Producer和Consumer获取Broker地址

Producer：产生并发送消息

Consumer：接受并消费消息

Broker：消息暂存，消息转发

 

Name Server

Name Server是RocketMQ的寻址服务。用于把Broker的路由信息做聚合。客户端依靠Name Server决定去获取对应topic的路由信息，从而决定对哪些Broker做连接。

Name Server是一个几乎无状态的结点，Name Server之间采取share-nothing的设计，互不通信。

对于一个Name Server集群列表，客户端连接Name Server的时候，只会选择随机连接一个结点，以做到负载均衡。

Name Server所有状态都从Broker上报而来，本身不存储任何状态，所有数据均在内存。

如果中途所有Name Server全都挂了，影响到路由信息的更新，不会影响和Broker的通信。

Broker

Broker是处理消息存储，转发等处理的服务器。

Broker以group分开，每个group只允许一个master，若干个slave。

只有master才能进行写入操作，slave不允许。

slave从master中同步数据。同步策略取决于master的配置，可以采用同步双写，异步复制两种。

客户端消费可以从master和slave消费。在默认情况下，消费者都从master消费，在master挂后，客户端由于从Name Server中感知到Broker挂机，就会从slave消费。

Broker向所有的NameServer结点建立长连接，注册Topic信息。

RocketMQ优点

1.强调集群无单点，可扩展

2.任意一点高可用，水平可扩展

3.海量消息堆积能力，消息堆积后，写入低延迟。

4.支持上万个队列

5.消息失败重试机制

6.消息可查询

7.开源社区活跃

8.成熟度（经过双十一考验）

RocketMQ环境安装

服务器配置

192.168.110.187 nameServer1,brokerServer1

192.168.110.188 nameServer2,brokerServer2

添加Host文件

vi /etc/hosts

192.168.110.187 rocketmq-nameserver1

192.168.110.187 rocketmq-master1

192.168.110.188 rocketmq-nameserver2

192.168.110.188 rocketmq-master2

service network restart

注意: Error:No suitable device found: no device found for connection "System eth0"

解决办法:

(1)ifconfig -a 查看物理 MAC HWADDR 的值

(2)vim 编辑文件 /etc/sysconfig/network-scripts/ifcfg-eth0中修改ifconfig中查出的MAC HWADDR值；

上传安装包

# 上传alibaba-rocketmq-3.2.6.tar.gz文件至/usr/local

# tar -zxvf alibaba-rocketmq-3.2.6.tar.gz -C /usr/local

# mv alibaba-rocketmq alibaba-rocketmq-3.2.6

# ln -s alibaba-rocketmq-3.2.6 rocketmq

创建存储路径【两台机器】

mkdir /usr/local/rocketmq/store

# mkdir /usr/local/rocketmq/store/commitlog

# mkdir /usr/local/rocketmq/store/consumequeue

# mkdir /usr/local/rocketmq/store/index

RocketMQ配置文件【两台机器】

# vim /usr/local/rocketmq/conf/2m-noslave/broker-a.properties

# vim /usr/local/rocketmq/conf/2m-noslave/broker-b.properties

修改日志配置文件【两台机器】

# mkdir -p /usr/local/rocketmq/logs

# cd /usr/local/rocketmq/conf && sed -i 's#${user.home}#/usr/local/rocketmq#g' *.xml

修改启动NameServer【两台机器】

vim /usr/local/rocketmq/bin/runbroker.sh

JAVA_OPT="${JAVA_OPT} -server -Xms1g -Xmx1g -Xmn512m -
XX:PermSize=128m -XX:MaxPermSize=320m"

vim /usr/local/rocketmq/bin/runserver.sh

JAVA_OPT="${JAVA_OPT} -server -Xms1g -Xmx1g -Xmn512m -
XX:PermSize=128m -XX:MaxPermSize=320m"

启动NameServer【两台机器】

# cd /usr/local/rocketmq/bin
# nohup sh mqnamesrv &

启动BrokerServer A

cd /usr/local/rocketmq/bin
# nohup sh mqbroker -c /usr/local/rocketmq/conf/2m-noslave/broker-a.properties >/dev/null 2>&1 &
# netstat -ntlp
# jps
# tail -f -n 500 /usr/local/rocketmq/logs/rocketmqlogs/broker.log
# tail -f -n 500 /usr/local/rocketmq/logs/rocketmqlogs/namesrv.log

启动BrokerServer B

cd /usr/local/rocketmq/bin
# nohup sh mqbroker -c /usr/local/rocketmq/conf/2m-noslave/broker-b.properties >/dev/null 2>&1 &
# netstat -ntlp
# jps
# tail -f -n 500 /usr/local/rocketmq/logs/rocketmqlogs/broker.log
# tail -f -n 500 /usr/local/rocketmq/logs/rocketmqlogs/namesrv.log

RocketMQ Console

将rocketmq-web-console 部署到webapps目录中。

/usr/local/apache-tomcat-7.0.65/webapps/rocketmq-web-console/WEB-INF/classes/

修改config.properties

rocketmq.namesrv.addr=192.168.110.195:9876;192.168.110.199:9876

运行效果

安装jdk环境

vi /etc/profile

export JAVA_HOME=/usr/local/jdk1.7.0_80

export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar

export PATH=$JAVA_HOME/bin:$PATH

source /etc/profile

Java操作RocketMQ

Pom

<dependencies>

              <dependency>

                     <groupId>com.alibaba.rocketmq</groupId>

                     <artifactId>rocketmq-client</artifactId>

                     <version>3.0.10</version>

              </dependency>

              <dependency>

                     <groupId>com.alibaba.rocketmq</groupId>

                     <artifactId>rocketmq-all</artifactId>

                     <version>3.0.10</version>

                     <type>pom</type>

              </dependency>

              <dependency>

                     <groupId>ch.qos.logback</groupId>

                     <artifactId>logback-classic</artifactId>

                     <version>1.1.1</version>

              </dependency>

              <dependency>

                     <groupId>ch.qos.logback</groupId>

                     <artifactId>logback-core</artifactId>

                     <version>1.1.1</version>

              </dependency>

              <dependency>

                     <groupId>junit</groupId>

                     <artifactId>junit</artifactId>

                     <version>4.10</version>

                     <scope>test</scope>

              </dependency>

       </dependencies>

生产者

public class Producer {

       public static void main(String[] args) throws MQClientException {

              DefaultMQProducer producer = new DefaultMQProducer("rmq-group");

              producer.setNamesrvAddr("192.168.110.195:9876;192.168.110.199:9876");

              producer.setInstanceName("producer");

              producer.start();

              try {

                     for (int i = 0; i < 10; i++) {

                            Thread.sleep(1000); // 每秒发送一次MQ

                            Message msg = new Message("yanggaige-topic", // topic 主题名称

                                          "TagA", // tag 临时值

                                          ("yanggaige-"+i).getBytes()// body 内容

                            );

                            SendResult sendResult = producer.send(msg);

                            System.out.println(sendResult.toString());

                     }

              } catch (Exception e) {

                     e.printStackTrace();

              }

              producer.shutdown();

       }

}

消费者

public class Consumer {

       public static void main(String[] args) throws MQClientException {

              DefaultMQPushConsumer consumer = new DefaultMQPushConsumer("rmq-group");

              consumer.setNamesrvAddr("192.168.110.195:9876;192.168.110.199:9876");

              consumer.setInstanceName("consumer");

              consumer.subscribe("yanggaige-topic", "TagA");

              consumer.registerMessageListener(new MessageListenerConcurrently() {

                     @Override

                     public ConsumeConcurrentlyStatus consumeMessage(List<MessageExt> msgs, ConsumeConcurrentlyContext context) {

                            for (MessageExt msg : msgs) {

                                   System.out.println(msg.getMsgId()+"---"+new String(msg.getBody()));

                            }

                            return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;

                     }

              });

              consumer.start();

              System.out.println("Consumer Started.");

       }

}

RocketMQ重试机制

MQ 消费者的消费逻辑失败时，可以通过设置返回状态达到消息重试的结果。

MQ 消息重试只针对集群消费方式生效；广播方式不提供失败重试特性，即消费失败后，失败消息不再重试，继续消费新的消息。

public class Consumer {

       public static void main(String[] args) throws MQClientException {

              DefaultMQPushConsumer consumer = new DefaultMQPushConsumer("rmq-group");

              consumer.setNamesrvAddr("192.168.110.195:9876;192.168.110.199:9876");

              consumer.setInstanceName("consumer");

              consumer.subscribe("yanggaige-topic", "TagA");

              consumer.registerMessageListener(new MessageListenerConcurrently() {

                     @Override

                     public ConsumeConcurrentlyStatus consumeMessage(List<MessageExt> msgs, ConsumeConcurrentlyContext context) {

                            for (MessageExt msg : msgs) {

                                   System.out.println(msg.getMsgId() + "---" + new String(msg.getBody()));

                            }

                            try {

                                   int i = 1 / 0;

                            } catch (Exception e) {

                                   e.printStackTrace();

                                // 需要重试

                                   return ConsumeConcurrentlyStatus.RECONSUME_LATER;

                            }

                         // 不需要重试

                            return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;

                     }

              });

              consumer.start();

              System.out.println("Consumer Started.");

       }

}

注意:每次重试后，消息ID都不一致，所以不能使用消息ID判断幂等。

RocketMQ如何解决消息幂等

注意:每次重试后，消息ID都不一致，所以不能使用消息ID判断幂等。

解决办法:使用自定义全局ID判断幂等，例如流水ID、订单号

使用msg.setKeys 进行区分

生产者:

public class Producer {

     public static void main(String[] args) throws MQClientException {

           DefaultMQProducer producer = new DefaultMQProducer("rmq-group");

           producer.setNamesrvAddr("192.168.110.195:9876;192.168.110.199:9876");

           producer.setInstanceName("producer");

           producer.start();

           try {

                for (int i = 0; i < 1; i++) {

                     Thread.sleep(1000); // 每秒发送一次MQ

                     Message msg = new Message("yanggaige-topic", // topic 主题名称

                                "TagA", // tag 临时值

                                ("yanggaige-6" + i).getBytes()// body 内容

                     );

                     msg.setKeys(System.currentTimeMillis() + "");

                     SendResult sendResult = producer.send(msg);

                     System.out.println(sendResult.toString());

                }

           } catch (Exception e) {

                e.printStackTrace();

           }

           producer.shutdown();

     }

}

消费者:

   static private Map<String, String> logMap = new HashMap<>();

       public static void main(String[] args) throws MQClientException {

              DefaultMQPushConsumer consumer = new DefaultMQPushConsumer("rmq-group");

              consumer.setNamesrvAddr("192.168.110.195:9876;192.168.110.199:9876");

              consumer.setInstanceName("consumer");

              consumer.subscribe("yanggaige-topic", "TagA");

              consumer.registerMessageListener(new MessageListenerConcurrently() {

                     @Override

                     public ConsumeConcurrentlyStatus consumeMessage(List<MessageExt> msgs, ConsumeConcurrentlyContext context) {

                            String key = null;

                            String msgId = null;

                            try {

                                   for (MessageExt msg : msgs) {

                                          key = msg.getKeys();

                                          if (logMap.containsKey(key)) {

                                                 // 无需继续重试。

                                                 System.out.println("key:"+key+",无需重试...");

                                                 return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;

                                          }

                                          msgId = msg.getMsgId();

                                          System.out.println("key:" + key + ",msgid:" + msgId + "---" + new String(msg.getBody()));

                                          int i = 1 / 0;

                                   }

                            } catch (Exception e) {

                                   e.printStackTrace();

                                   return ConsumeConcurrentlyStatus.RECONSUME_LATER;

                            } finally {

                                   logMap.put(key, msgId);

                            }

                            return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;

                     }

              });

              consumer.start();

              System.out.println("Consumer Started.");

       }

参考文献

https://help.aliyun.com/document_detail/44397.html?spm=a2c4g.11186623.6.577.sPsbuu

 

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