1. 为什么需要dubbo
2. Dubbo的架构
3. Dubbo的使用
Dubbo服务端启动之后，如果注册中心是使用的zookeeper，dubbo会默认在zookeeper根节点下建立dubbo节点，该节点下节点如下
[zk: localhost:2181(CONNECTED) 11] ls /
[dubbo, shen, zookeeper]
[zk: localhost:2181(CONNECTED) 12] ls /dubbo
[com.smallShen.dubbo.IHelloService]
[zk: localhost:2181(CONNECTED) 13] ls /dubbo/com.smallShen.dubbo.IHelloService
[consumers, configurators, routers, providers]
[zk: localhost:2181(CONNECTED) 14] ls /dubbo/com.smallShen.dubbo.IHelloService/providers
[dubbo%3A%2F%2F169.254.233.251%3A21888%2Fcom.smallShen.dubbo.IHelloService%3Fanyhost%3Dtrue%26application%3Ddubbo-shen-server%26dubbo%3D2.5.3%26interface%3Dcom.smallShen.dubbo.IHelloService%26methods%3DsayHello%26owner%3DsmallShen%26pid%3D22064%26side%3Dprovider%26timestamp%3D1562157806120]