（一）dubbo 常用通讯协议

（一）dubbo 通讯协议的几种配置方式

（1）服务端提供统一的一个通讯协议，既多个服务端口使用一个通讯协议

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:dubbo="http://dubbo.apache.org/schema/dubbo"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd http://dubbo.apache.org/schema/dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd">
    <dubbo:application name="world"  />
    <dubbo:registry id="registry" address="10.20.141.150:9090" username="admin" password="hello1234" />
    <dubbo:protocol name="dubbo" port="20880" />
    <!-- Use dubbo protocol to expose the service -->
    <dubbo:service interface="com.alibaba.hello.api.HelloService" version="1.0.0" ref="helloService" />
    <dubbo:service interface="com.alibaba.hello.api.DemoService" version="1.0.0" ref="demoService" />
</beans>

（2）一个服务接口配置一种通讯协议

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:dubbo="http://dubbo.apache.org/schema/dubbo"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd http://dubbo.apache.org/schema/dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd">
    <dubbo:application name="world"  />
    <dubbo:registry id="registry" address="10.20.141.150:9090" username="admin" password="hello1234" />
    <!-- multiple protocols -->
    <dubbo:protocol name="dubbo" port="20880" />
    <dubbo:protocol name="rmi" port="1099" />
    <!-- Use dubbo protocol to expose the service -->
    <dubbo:service interface="com.alibaba.hello.api.HelloService" version="1.0.0" ref="helloService" protocol="dubbo" />
    <!-- Use rmi protocol to expose services -->
    <dubbo:service interface="com.alibaba.hello.api.DemoService" version="1.0.0" ref="demoService" protocol="rmi" />
</beans>

（3）一个服务接口配置多个通讯协议

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:dubbo="http://dubbo.apache.org/schema/dubbo"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd http://dubbo.apache.org/schema/dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd">
    <dubbo:application name="world"  />
    <dubbo:registry id="registry" address="10.20.141.150:9090" username="admin" password="hello1234" />
    <!-- multiple protocols-->
    <dubbo:protocol name="dubbo" port="20880" />
    <dubbo:protocol name="hessian" port="8080" />
    <!-- Service exposes multiple protocols -->
    <dubbo:service id="helloService" interface="com.alibaba.hello.api.HelloService" version="1.0.0" protocol="dubbo,hessian" />
</beans>

参考：http://dubbo.apache.org/zh-cn/docs/user/demos/multi-protocols.html

（二）各个协议特点

dubbo协议

rmi协议

hessian协议

http协议

redis协议