【学习】025 RocketMQ

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

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:

package com.hongmoshui.test3;
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 < 1; 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());
                msg.setKeys(System.currentTimeMillis() + "");
                SendResult sendResult = producer.send(msg);
                System.out.println(sendResult.toString());
            }
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
        producer.shutdown();
    }

}

消费者:

package com.hongmoshui.test3;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
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
{
    static private Map<String, String> logMap = new HashMap<String, String>();

    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)
            {
                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.");
    }

}