1： http://mcollina.github.io/mqtt_and_nodejs/#16
2： https://github.com/mcollina/mosca/issues/119
3 ： http://blog.shiqichan.com/introducing-mqtt/
4：https://github.com/mcollina/mosca/wiki/Mosca-advanced-usage
5： https://github.com/mcollina/mosca/wiki/Mosca-basic-usage#in-this-example-we-will-be-using-redis
6： https://github.com/mqttjs/MQTT.js/issues/259
7： http://emqtt.cn/getstarted
8: https://github.com/emqtt/emqtt
