Apache RocketMQ4.0.0
阿里rocketmq，有广泛的应用场景，订单，交易，充值，流计算，消息推送，日志流式处理，binglog分发等多个业务领域。
已正式成为apache项目，也于年前刚发布4.0.0版本，本文初试服务端和客户端
1 服务端安装
1.0 安装准备
CentOS release 6.8 (Final)
- 64bit OS, Linux/Unix/Mac is recommended;
- 64bit JDK 1.7+;
- Maven 3.2.x
- Git
1.1 编译
> git clone https://github.com/apache/incubator-rocketmq.git
> cd incubator-rocketmq
> mvn clean package install -Prelease-all assembly:assembly -U
> cd target/apache-rocketmq-all/
1.2 启动NameServer
> nohup sh bin/mqnamesrv &
> tail -f ~/logs/rocketmqlogs/namesrv.log
The Name Server boot success...
1.3 启动Broker
> nohup sh bin/mqbroker -n localhost:9876 &
> tail -f ~/logs/rocketmqlogs/broker.log
The broker[%s, 172.30.30.233:10911] boot success...
2 客户端
2.1 客户示例客户端
运行生产者producer
> export NAMESRV_ADDR=localhost:9876
> sh bin/tools.sh org.apache.rocketmq.example.quickstart.Producer
SendResult [sendStatus=SEND_OK, msgId= ...运行消费者
> sh bin/tools.sh org.apache.rocketmq.example.quickstart.Consumer
ConsumeMessageThread_%d Receive New Messages: [MessageExt...
2.2 java客户端编写
pom.xmlsg
<rocketmq.version>4.0.0-incubatingrocketmq.version>
<dependency>
<groupId>org.apache.rocketmqgroupId>
<artifactId>rocketmq-clientartifactId>
<version>${rocketmq.version}version>
dependency>
<dependency>
<groupId>org.apache.rocketmqgroupId>
<artifactId>rocketmq-allartifactId>
<version>${rocketmq.version}version>
dependency>
生产者
import org.apache.rocketmq.client.exception.MQClientException;
import org.apache.rocketmq.client.producer.DefaultMQProducer;
import org.apache.rocketmq.client.producer.SendResult;
import org.apache.rocketmq.common.message.Message;
import java.util.concurrent.TimeUnit;
public class Producer {
public static void main(String[] args) throws MQClientException,
InterruptedException {
/**
* 一个应用创建一个Producer，由应用来维护此对象，可以设置为全局对象或者单例
* 注意：ProducerGroupName需要由应用来保证唯一
* ProducerGroup这个概念发送普通的消息时，作用不大，但是发送分布式事务消息时，比较关键，
* 因为服务器会回查这个Group下的任意一个Producer
*/
DefaultMQProducer producer = new DefaultMQProducer("ProducerGroupName");
producer.setNamesrvAddr("192.168.56.101:9876");
producer.setInstanceName("Producer");
producer.setVipChannelEnabled(false);
/**
* Producer对象在使用之前必须要调用start初始化，初始化一次即可
* 注意：切记不可以在每次发送消息时，都调用start方法
*/
producer.start();
/**
* 下面这段代码表明一个Producer对象可以发送多个topic，多个tag的消息。
* 注意：send方法是同步调用，只要不抛异常就标识成功。但是发送成功也可会有多种状态，
* 例如消息写入Master成功，但是Slave不成功，这种情况消息属于成功，但是对于个别应用如果对消息可靠性要求极高，
* 需要对这种情况做处理。另外，消息可能会存在发送失败的情况，失败重试由应用来处理。
*/
for (int i = 0; i < 1; i++) {
try {
{
Message msg = new Message("TopicTest1",// topic
"TagA",// tag
"OrderID001",// key
("Hello MetaQ").getBytes());// body
SendResult sendResult = producer.send(msg);
System.out.println(sendResult);
}
{
Message msg = new Message("TopicTest2",// topic
"TagB",// tag
"OrderID0034",// key
("Hello MetaQ").getBytes());// body
SendResult sendResult = producer.send(msg);
System.out.println(sendResult);
}
{
Message msg = new Message("TopicTest3",// topic
"TagC",// tag
"OrderID061",// key
("Hello MetaQ").getBytes());// body
SendResult sendResult = producer.send(msg);
System.out.println(sendResult);
}
} catch (Exception e) {
e.printStackTrace();
}
TimeUnit.MILLISECONDS.sleep(1000);
}
/**
* 应用退出时，要调用shutdown来清理资源，关闭网络连接，从MetaQ服务器上注销自己
* 注意：我们建议应用在JBOSS、Tomcat等容器的退出钩子里调用shutdown方法
*/
producer.shutdown();
}
}
消费者
import org.apache.rocketmq.client.consumer.DefaultMQPushConsumer;
import org.apache.rocketmq.client.consumer.listener.ConsumeConcurrentlyContext;
import org.apache.rocketmq.client.consumer.listener.ConsumeConcurrentlyStatus;
import org.apache.rocketmq.client.consumer.listener.MessageListenerConcurrently;
import org.apache.rocketmq.client.exception.MQClientException;
import org.apache.rocketmq.common.message.MessageExt;
import java.util.List;
public class PushConsumer {
/**
* 当前例子是PushConsumer用法，使用方式给用户感觉是消息从RocketMQ服务器推到了应用客户端。
* 但是实际PushConsumer内部是使用长轮询Pull方式从MetaQ服务器拉消息，然后再回调用户Listener方法
*/
public static void main(String[] args) throws InterruptedException,
MQClientException {
/**
* 一个应用创建一个Consumer，由应用来维护此对象，可以设置为全局对象或者单例
* 注意：ConsumerGroupName需要由应用来保证唯一
*/
DefaultMQPushConsumer consumer = new DefaultMQPushConsumer(
"ConsumerGroupName");
consumer.setNamesrvAddr("192.168.56.101:9876");
consumer.setInstanceName("Consumber");
/**
* 订阅指定topic下tags分别等于TagA或TagC或TagD
*/
consumer.subscribe("TopicTest1", "TagA || TagC || TagD");
/**
* 订阅指定topic下所有消息
* 注意：一个consumer对象可以订阅多个topic
*/
consumer.subscribe("TopicTest2", "*");
consumer.registerMessageListener(new MessageListenerConcurrently() {
/**
* 默认msgs里只有一条消息，可以通过设置consumeMessageBatchMaxSize参数来批量接收消息
*/
@Override
public ConsumeConcurrentlyStatus consumeMessage(
List msgs, ConsumeConcurrentlyContext context) {
System.out.println(Thread.currentThread().getName()
+ " Receive New Messages: " + msgs.size());
MessageExt msg = msgs.get(0);
if (msg.getTopic().equals("TopicTest1")) {
// 执行TopicTest1的消费逻辑
if (msg.getTags() != null && msg.getTags().equals("TagA")) {
// 执行TagA的消费
System.out.println(new String(msg.getBody()));
} else if (msg.getTags() != null
&& msg.getTags().equals("TagC")) {
// 执行TagC的消费
} else if (msg.getTags() != null
&& msg.getTags().equals("TagD")) {
// 执行TagD的消费
}
} else if (msg.getTopic().equals("TopicTest2")) {
System.out.println(new String(msg.getBody()));
}
return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;
}
});
/**
* Consumer对象在使用之前必须要调用start初始化，初始化一次即可
*/
consumer.start();
System.out.println("Consumer Started.");
}
}
安装中问题汇总：
> nohup sh bin/mqnamesrv &先不使用以上命令，如果出错，不会有显示
使用
sh bin/mqnamesrv出现以下问题
#
# There is insufficient memory for the Java Runtime Environment to continue.
# Native memory allocation (mmap) failed to map 805306368 bytes for committing reserved memory.
# Possible reasons:
# The system is out of physical RAM or swap space
# In 32 bit mode, the process size limit was hit
# Possible solutions:
# Reduce memory load on the system
# Increase physical memory or swap space
# Check if swap backing store is full
# Use 64 bit Java on a 64 bit OS
# Decrease Java heap size (-Xmx/-Xms)
# Decrease number of Java threads
# Decrease Java thread stack sizes (-Xss)
# Set larger code cache with -XX:ReservedCodeCacheSize=
# This output file may be truncated or incomplete.
#
# Out of Memory Error (os_linux.cpp:2627), pid=1864, tid=0x00007f94d8319700原因：rocketmq默认jvm配置较高，导致内存不足
解决：
runserver.sh
改成
JAVA_OPT="${JAVA_OPT} -server -Xms256m -Xmx256m -Xmn128m -XX:PermSize=128m -XX:MaxPermSize=320m"
同理，运行其他命令也建议先使用sh来运行，解决方法如下
runbroker.sh
JAVA_OPT="${JAVA_OPT} -server -Xms8g -Xmx8g -Xmn4g"
改成：
JAVA_OPT="${JAVA_OPT} -server -Xms256m -Xmx256m -Xmn128m
tools.sh
JAVA_OPT="${JAVA_OPT} -server -Xms1g -Xmx1g -Xmn256m -XX:PermSize=128m -XX:MaxPermSize=128m"
改成
JAVA_OPT="${JAVA_OPT} -server -Xms256m -Xmx256m -Xmn128m -XX:PermSize=128m -XX:MaxPermSize=128m"
调试时问题汇总：
运行java客户端的Producer.java，出现
| Caused by: org.apache.rocketmq.remoting.exception.RemotingConnectException: connect to <*****:10911> failed |
经调试，
org.apache.rocketmq.client.impl.producer.DefaultMQProducerImplString brokerAddr = this.mQClientFactory.findBrokerAddressInPublish(mq.getBrokerName());通过broderName获取到的ip不正确
解决：临时解决方案是断点在该代码下方，将brokerAddr设置为正确ip
reference:
https://rocketmq.incubator.apache.org/docs/quick-start/
http://www.tuicool.com/articles/mEBVneB
扩展阅读：
RocketMQ与Kafka对比（18项差异） http://blog.csdn.net/damacheng/article/details/42846549
Rocketmq源码分析（一）整体架构 https://yq.aliyun.com/articles/61141#
RocketMQ 源码分析 http://blog.csdn.net/vonzhoufz/article/details/47191883