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/localtar -zxvf alibaba-rocketmq-3.2.6.tar.gz -C /usr/localmv alibaba-rocketmq alibaba-rocketmq-3.2.6ln -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/binnohup 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 -ntlpjpstail -f -n 500 /usr/local/rocketmq/logs/rocketmqlogs/broker.logtail -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 -ntlpjpstail -f -n 500 /usr/local/rocketmq/logs/rocketmqlogs/broker.logtail -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文件依赖

    <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

package com.hongmoshui;
import com.alibaba.rocketmq.client.exception.MQClientException;
import com.alibaba.rocketmq.client.producer.DefaultMQProducer;
import com.alibaba.rocketmq.client.producer.SendResult;
import com.alibaba.rocketmq.common.message.Message;
 
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++)
            {
                // 每秒发送一次MQ
                Thread.sleep(1000);
                // topic:主题名称,tag:临时值,body:内容
                Message msg = new Message("hongmoshui-topic", "TagA", ("hongmoshui-" + i).getBytes());
                SendResult sendResult = producer.send(msg);
                System.out.println(sendResult.toString());
            }
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
        producer.shutdown();
    }
}

消费者

package com.hongmoshui;
 
import java.util.List;
 
import com.alibaba.rocketmq.client.consumer.DefaultMQPushConsumer;
import com.alibaba.rocketmq.client.consumer.listener.ConsumeConcurrentlyContext;
import com.alibaba.rocketmq.client.consumer.listener.ConsumeConcurrentlyStatus;
import com.alibaba.rocketmq.client.consumer.listener.MessageListenerConcurrently;
import com.alibaba.rocketmq.client.exception.MQClientException;
import com.alibaba.rocketmq.common.message.MessageExt;
 
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("hongmoshui-topic", "TagA");
 
        consumer.registerMessageListener(new MessageListenerConcurrently()
        {
            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。

package com.hongmoshui.test2;
import java.util.List;
import com.alibaba.rocketmq.client.consumer.DefaultMQPushConsumer;
import com.alibaba.rocketmq.client.consumer.listener.ConsumeConcurrentlyContext;
import com.alibaba.rocketmq.client.consumer.listener.ConsumeConcurrentlyStatus;
import com.alibaba.rocketmq.client.consumer.listener.MessageListenerConcurrently;
import com.alibaba.rocketmq.client.exception.MQClientException;
import com.alibaba.rocketmq.common.message.MessageExt;
 
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("hongmoshui-topic", "TagA");
        consumer.registerMessageListener(new MessageListenerConcurrently()
        {
            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