https://www.cnblogs.com/kakaisgood/p/9541953.html 集群/分布式/微服务/SOA的解释
https://www.cnblogs.com/williamjie/p/9481780.html MQ消息队列
https://github.com/doocs/advanced-java java攻城狮进阶知识大全
https://shimo.im/docs/oS154HRccNgiXhbl/read 并发线程入门
https://shimo.im/docs/gVPRtCDVK3QPtVwC/read 深入理解JVN
https://hellogithub.com/ HelloGitHub 分享 GitHub 上入门级、有趣的开源项目
https://blog.csdn.net/m15927408113/article/details/71439116#commentsedit MQTT+ActiveMQ实现消息推送（服务端）
https://blog.csdn.net/r1037/article/details/78222114
https://www.cnblogs.com/yangfengwu/p/7764667.html 安装MQTT服务器
https://blog.csdn.net/m15927408113/article/details/71438922 MQTT+ActiveMQ实现消息推送（移动端）