一. 简介
引用其他文章：
Apache Apollo是一个代理服务器，其是在ActiveMQ基础上发展而来的，可以支持STOMP, AMQP, MQTT, Openwire, SSL, and WebSockets 等多种协议。
Apollo允许客户端通过开放的MQTT协议连接。该协议主要是用在资源有限的驱动上，以及网络不稳定的情况下使用，是一个订阅、发布模型。这种驱动通常不适用类似http，stomp这类基于文本，或者类似openfire，AMQP等传统二进制协议。MQTT是一个简介的二进制协议，适用这类驱动资源受限，而且是不稳定的网络条件下。之前的稳定发布版本中，MQTT是作为一个Apollo的一个插件提供的。但是现在，这个插件已经变为开发项目的一部分。MQTT在Apollo中已经不需要其他配置文件或者是第三方插件支持了。
MQTT是一个线路层的协议，任何实现该协议的客户端都可以连接到Apollo。当然也可以整合其他MQTT兼容的消息代理中。
二. Mac下apollo安装
1.下载
apollo下载以及源代码下载
2.解压
3. 添加环境变量
APOLLO_HOME=解压目录
4. 新建broker目录，最好不要跟APOLLO_HOME一致，便于以后升级
5. 创建broker
1. cd broker目录
2. ${APOLLO_HOME}/bin/apollo create mybroker
注意windows下命令可能不同，应该可以直接把apollo.bat拖过来执行。
执行完之后，应该会提示怎么运行：
You can now start the broker by executing: "/Users/huangrongwei/Documents/1_work_project/apache_apollo/apollo_broker/mybroker/bin/apollo-broker" run Or you can run the broker in the background using: "/Users/huangrongwei/Documents/1_work_project/apache_apollo/apollo_broker/mybroker/bin/apollo-broker-service" start
6. 运行broker
按照上面的提示，选择一个运行。第一个是前台运行，就是会占用你的命令行，不会退出。
下面一个命令是后台运行。
7.查看apollo进程
ps -elf | grep apollo
结果如下；
501 5418 5361 400e 0 31 0 5048532 125212 - S+ 0 ttys006 2:00.45 apollo -ea -serv 1:27下午
8. 浏览器查看结果
http://127.0.0.1:61680/ 或者 https://127.0.0.1:61681/
第一个是http的，后面一个是https的。
默认登录的用户名是admin/password，这样就可以看到apollo的管理界面。
三. 客户端测试apollo
在apollo的解压文件夹里面有个example文件夹，里面有个mqtt->java
用eclipse导入这个maven工程(eclipse->file->import->maven project)，注意可能需要安装maven eclipse插件
然后里面有个Listener.java和Publisher.java，可以订阅和发布消息。直接右击->Run as java application启动起来。
然后看输出结果。
Listener.java最后会输入下面的消息。表示1万条消息接受花费了0.93秒
Received 0 messages. Received 1000 messages. Received 2000 messages. Received 3000 messages. Received 4000 messages. Received 5000 messages. Received 6000 messages. Received 7000 messages. Received 8000 messages. Received 9000 messages. Received 10000 in 0.93 seconds
四. 其他
1. curl访问apollo
curl -u "admin:password" http://localhost:61680/broker.json
结果{"id":"default","state":"STARTED","state_since":1499318856654,"version":"1.7.1","home_location":"/Users/huangrongwei/Documents/1_work_project/apache_apollo/apache-apollo-1.7.1","base_location":"/Users/huangrongwei/Documents/1_work_project/apache_apollo/apollo_broker/mybroker","jvm_metrics":{"heap_memory":{"used":23072848,"alloc":79691776,"max":954728448},"non_heap_memory":{"used":71784880,"alloc":74203136,"max":-1},"classes_loaded":7893,"classes_unloaded":0,"threads_current":27,"threads_peak":32,"os_arch":"x86_64","os_name":"Mac OS X 10.12.4","os_memory_total":8589934592,"os_memory_free":60743680,"os_swap_total":0,"os_swap_free":1073741824,"os_fd_open":135,"os_fd_max":6250,"os_load_average":2.90869140625,"os_cpu_time":128597245000,"os_processors":4,"runtime_name":"[email protected]","jvm_name":"Java HotSpot(TM) 64-Bit Server VM 1.8.0_131 (Oracle Corporation)","uptime":14200613,"start_time":1499318843487},"current_time":1499333764968,"virtual_hosts":["mybroker"],"connectors":["tcp","tls","ws","wss"],"connection_counter":16,"connected":0,"messages_sent":80008,"messages_received":70007,"read_counter":19251413,"write_counter":22040503}
2. mqtt协议内容
http://public.dhe.ibm.com/software/dw/webservices/ws-mqtt/mqtt-v3r1.html#fixed-header