RocketMQ User Guide

whatsmars-mq/README.md

-### [RocketMQ](https://github.com/apache/rocketmq)
+# [RocketMQ](https://github.com/apache/rocketmq)
+
+### Test
 - .properties指定rocketmqHome,namesrvAddr等，依次启动NamesrvStartup,BrokerStartup,Consumer,Producer
 - 管理后台：https://github.com/apache/rocketmq-externals
+
+### User Guide
 - rocketmq原理与实践 http://wely.iteye.com/blog/2392089
+- 每个主题可设置队列个数，默认4个，需要顺序消费的消息发往同一队列，比如同一订单号相关的几条需要顺序消费的消息发往同一队列，
+顺序消费的特点的是，不会有两个消费者共同消费任一队列，且当消费者数量小于队列数时，消费者会消费多个队列。至于消息重复，在消
+费端处理。事务消息可参考rocketmq的做法，也可直接用本地事务。
+- Broker上存Topic信息，Topic由多个队列组成，队列会平均分散在多个Broker上，而Producer的发送机制保证消息尽量平均分布到
+所有队列中，最终效果就是所有消息都平均落在每个Broker上。
+- ConsumerQueue相当于CommitLog的索引文件，消费者消费时会先从ConsumerQueue中查找消息的在commitLog中的offset，再去
+CommitLog中找元数据。如果某个消息只在CommitLog中有数据，没在ConsumerQueue中， 则消费者无法消费，RocketMQ的事务消息就
+是这个原理。
 
 Other MQ: https://github.com/javahongxi/whatsmars/blob/master/whatsmars-mq/othermq.md

whatsmars-mq/pom.xml

@@ -66,12 +66,6 @@
             <artifactId>amqp-client</artifactId>
         </dependency>
 
-        <dependency>
-            <groupId>org.zeromq</groupId>
-            <artifactId>jeromq</artifactId>
-            <version>0.4.2</version>
-        </dependency>
-
         <dependency>
             <groupId>org.apache.kafka</groupId>
             <artifactId>kafka_2.8.2</artifactId>

whatsmars-mq/src/main/java/org/hongxi/whatsmars/mq/zeromq/Publisher.java

-package org.hongxi.whatsmars.mq.zeromq;
-
-import org.zeromq.ZMQ;
-
-public class Publisher {
-
-    public static void main(String args[]) {
-        ZMQ.Context context = ZMQ.context(1); // 创建包含一个I/O线程的context
-        ZMQ.Socket publisher = context.socket(ZMQ.PUB);
-        publisher.bind("tcp://*:5555");
- 
-        while (!Thread.currentThread ().isInterrupted()) {
-            String message = "toutiao hello";
-            publisher.send(message.getBytes());
-            System.out.println("sent : " + message);
-        }  
- 
-        publisher.close();  
-        context.term();  
-    }  
-}
\ No newline at end of file

whatsmars-mq/src/main/java/org/hongxi/whatsmars/mq/zeromq/Subscriber.java

-package org.hongxi.whatsmars.mq.zeromq;
-
-import org.zeromq.ZMQ;
-
-public class Subscriber {
-
-    public static void main(String args[]) {  
-        for (int j = 0; j < 10; j++) {
-            new Thread(new Runnable(){
-                public void run() {  
-                    ZMQ.Context context = ZMQ.context(1);
-                    ZMQ.Socket subscriber = context.socket(ZMQ.SUB);
-                    subscriber.connect("tcp://127.0.0.1:5555");
-                    subscriber.subscribe("toutiao".getBytes());
-
-                    try {
-                        while (true) {
-                            byte[] message = subscriber.recv();
-                            System.out.println(Thread.currentThread().getName() + " receive : " + new String(message));
-                        }
-                    } finally {
-                        subscriber.close();
-                        context.term();
-                    }
-                }
-            }).start();  
-        }
-    }  
-}
\ No newline at end of file