Dubbo第一章：Dubbo-admin编译和Dubbo简单入门

Dear 丶 2022-06-04 09:36 231阅读 0赞

# 背景 #

Dubbo的开源人梁飞在内部的交流会上宣布重启dubbo的维护和更新，具体PPT内容请看我的个人订阅号。

因此本文基于2017-12-10号的维护的版本dubbo-2.5.7。

这里为何从Dubbo-admin开始，这不是最重要的部分，但是却是dubbo源码编译最简单的部分。

## 准备工作 ##

按照zookeeper服务（参考单机安装[zookeeper安装][zookeeper]）

下载dubbo源码  
[https://github.com/alibaba/dubbo/releases/tag/dubbo-2.5.7][https_github.com_alibaba_dubbo_releases_tag_dubbo-2.5.7]

当然也可以直接从我的github上面直接下载已经编译好了的war包  
[https://github.com/BambooZhang/dubbo-study][https_github.com_BambooZhang_dubbo-study]

## dubbo-admin编译 ##

解压后这里只用到一个项目就是dubbo-admin

cd D:\git_space\dubbo-dubbo-2.5.7\dubbo-dubbo-2.5.7\dubbo-admin
    mvn package -Dmaven.skip.test=true

出现下面的结果则说明编译成功

[INFO]
    [INFO] --- maven-war-plugin:2.2:war (default-war) @ dubbo-admin ---
    [INFO] Packaging webapp
    [INFO] Assembling webapp [dubbo-admin] in [D:\git_space\dubbo-dubbo-2.5.7\dubbo-dubbo-2.5.7\dubbo-admin\target\dubbo-admin-2.5.7]
    [INFO] Processing war project
    [INFO] Copying webapp resources [D:\git_space\dubbo-dubbo-2.5.7\dubbo-dubbo-2.5.7\dubbo-admin\src\main\webapp]
    [INFO] Webapp assembled in [880 msecs]
    [INFO] Building war: D:\git_space\dubbo-dubbo-2.5.7\dubbo-dubbo-2.5.7\dubbo-admin\target\dubbo-admin-2.5.7.war
    [INFO] WEB-INF\web.xml already added, skipping
    [INFO] ------------------------------------------------------------------------
    [INFO] BUILD SUCCESS
    [INFO] ------------------------------------------------------------------------
    [INFO] Total time: 24.516 s
    [INFO] Finished at: 2017-12-10T17:38:17+08:00
    [INFO] Final Memory: 19M/244M
    [INFO] ------------------------------------------------------------------------

### 部署dubbo-admin到tomcat ###

把target\\dubbo-admin-2.5.7下面的文件都拷贝到tomcat/webapps/ROOT下面

![这里写图片描述][SouthEast]

修改配置dubbo.properties  
zookeeper地址修改为自己安装的ip地址，默认是127.0.0.1

dubbo.registry.address=zookeeper://192.168.0.91:2181
    dubbo.admin.root.password=root
    dubbo.admin.guest.password=guest

### 启动dubbo-admin ###

首先启动zookeeper服务，在启动tomcat  
启动完成访问localhost:8080  
默认账号密码都是root  
![这里写图片描述][SouthEast 1]

## Dubbo服务提供者和消费者demo ##

dubbo-admin-2.5.7.war管理中心  
dubbo-provider服务器提供者  
dubbo-consumer服务器消费者

spring版本：4.3.9.RELEASE

### dubbo-provider服务器提供者 ###

![这里写图片描述][SouthEast 2]

### pom ###

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
      <modelVersion>4.0.0</modelVersion>
    
      <groupId>com.bamboo</groupId>
      <artifactId>dubbo-provider</artifactId>
      <version>0.0.1-SNAPSHOT</version>
      <packaging>jar</packaging>
    
      <name>dubbo-provider</name>
      <url>http://maven.apache.org</url>
    
    	<repositories>
    		<repository>
    			<id>maven-ali</id>
    			<url>http://maven.aliyun.com/nexus/content/groups/public/</url>
    			<releases>
    				<enabled>true</enabled>
    			</releases>
    			<snapshots>
    				<enabled>true</enabled>
    				<updatePolicy>always</updatePolicy>
    				<checksumPolicy>fail</checksumPolicy>
    			</snapshots>
    		</repository>
    
    	</repositories>
    
      <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <spring.version>4.3.9.RELEASE</spring.version>  
      </properties>
      
      
        <dependencies>  
            <dependency>  
                <groupId>com.alibaba</groupId>  
                <artifactId>dubbo</artifactId>  
                <version>2.5.7</version>  
                <exclusions>  
                    <exclusion>  
                        <groupId>org.springframework</groupId>  
                        <artifactId>spring</artifactId>  
                    </exclusion>  
                </exclusions>  
            </dependency>  
            <dependency>  
                <groupId>com.github.sgroschupf</groupId>  
                <artifactId>zkclient</artifactId>  
                <version>0.1</version>  
            </dependency>  
              
            <dependency>  
                <groupId>org.springframework</groupId>  
                <artifactId>spring-core</artifactId>  
                <version>${spring.version}</version>  
            </dependency>  
            <dependency>  
                <groupId>org.springframework</groupId>  
                <artifactId>spring-beans</artifactId>  
                <version>${spring.version}</version>  
            </dependency>  
            <dependency>  
                <groupId>org.springframework</groupId>  
                <artifactId>spring-context</artifactId>  
                <version>${spring.version}</version>  
            </dependency>  
            <dependency>  
                <groupId>org.springframework</groupId>  
                <artifactId>spring-jdbc</artifactId>  
                <version>${spring.version}</version>  
            </dependency>  
            <dependency>  
                <groupId>org.springframework</groupId>  
                <artifactId>spring-web</artifactId>  
                <version>${spring.version}</version>  
            </dependency>  
            <dependency>  
                <groupId>org.springframework</groupId>  
                <artifactId>spring-webmvc</artifactId>  
                <version>${spring.version}</version>  
            </dependency>  
            <dependency>  
                <groupId>org.springframework</groupId>  
                <artifactId>spring-aop</artifactId>  
                <version>${spring.version}</version>  
            </dependency>  
            <dependency>  
                <groupId>org.springframework</groupId>  
                <artifactId>spring-tx</artifactId>  
                <version>${spring.version}</version>  
            </dependency>  
            <dependency>  
                <groupId>org.springframework</groupId>  
                <artifactId>spring-orm</artifactId>  
                <version>${spring.version}</version>  
            </dependency>  
            <dependency>  
                <groupId>org.springframework</groupId>  
                <artifactId>spring-context-support</artifactId>  
                <version>${spring.version}</version>  
            </dependency>  
            <dependency>  
                <groupId>org.springframework</groupId>  
                <artifactId>spring-test</artifactId>  
                <version>${spring.version}</version>  
            </dependency>  
            <dependency>  
                <groupId>org.springframework</groupId>  
                <artifactId>spring-jms</artifactId>  
                <version>${spring.version}</version>  
            </dependency>  
            
        <dependency>
          <groupId>junit</groupId>
          <artifactId>junit</artifactId>
          <version>3.8.1</version>
          <scope>test</scope>
        </dependency>
      </dependencies>
    </project>

### applicationProvider.xml ###

<?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://code.alibabatech.com/schema/dubbo"  
        xsi:schemaLocation="http://www.springframework.org/schema/beans  
            http://www.springframework.org/schema/beans/spring-beans.xsd  
            http://code.alibabatech.com/schema/dubbo  
            http://code.alibabatech.com/schema/dubbo/dubbo.xsd ">   
          
        <bean id="providerService" class="com.bamboo.dubbo_provider.ProviderServiceImpl" />  
          
        <dubbo:application name="dubbo_provider"  />    
           
          
        <dubbo:registry address="zookeeper://192.168.0.91:2181" />     
          
        <dubbo:protocol name="dubbo" port="29014" />  
          
        <dubbo:service interface="com.bamboo.service.ProviderService" ref="providerService" />  
    </beans>

### java ###

service

package com.bamboo.service;
    
    public interface  ProviderService {
    
    	public String sayHello(String name);
    }

ProviderServiceImpl

package com.bamboo.dubbo_provider;
    
    import com.bamboo.service.ProviderService;
    
    public class ProviderServiceImpl implements ProviderService {  
      
        public String sayHello(String name) {         
            return "Hello:"+name+"你好，你好~~";  
        }  
      
    }

main.java

package com.bamboo.dubbo_provider;
    
    import java.io.IOException;
    
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    
    /**
     * dubbo 服务提供端
     * @author bamboo
     */
    public class App 
    {
    	public static void main(String[] args) {  
            ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(    
                    new String[]{"applicationProvider.xml"});
            context.start();   
            System.out.println("提供者服务已注册成功");    
            System.out.println("请按任意键取消提供者服务");    
            try {  
                System.in.read();//让此程序一直跑，表示一直提供服务  
            } catch (IOException e) {         
                e.printStackTrace();  
            }    
        }
    }

运行

log4j:WARN No appenders could be found for logger (org.springframework.core.env.StandardEnvironment).
    log4j:WARN Please initialize the log4j system properly.
    提供者服务已注册成功
    请按任意键取消提供者服务

## dubbo-consumer服务器消费者 ##

![这里写图片描述][SouthEast 3]

### pom ###

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
      <modelVersion>4.0.0</modelVersion>
    
      <groupId>com.bamboo</groupId>
      <artifactId>dubbo-consumer</artifactId>
      <version>0.0.1-SNAPSHOT</version>
      <packaging>jar</packaging>
    
      <name>dubbo-consumer</name>
      <url>http://maven.apache.org</url>
    
    		<repositories>
    		<repository>
    			<id>maven-ali</id>
    			<url>http://maven.aliyun.com/nexus/content/groups/public/</url>
    			<releases>
    				<enabled>true</enabled>
    			</releases>
    			<snapshots>
    				<enabled>true</enabled>
    				<updatePolicy>always</updatePolicy>
    				<checksumPolicy>fail</checksumPolicy>
    			</snapshots>
    		</repository>
    
    	</repositories>
    	
    	
      <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <spring.version>4.3.9.RELEASE</spring.version>  
      </properties>
    
       <dependencies>  
       
              
            <dependency>  
                <groupId>com.alibaba</groupId>  
                <artifactId>dubbo</artifactId>  
                <version>2.5.7</version>  
                <exclusions>  
                    <exclusion>  
                        <groupId>org.springframework</groupId>  
                        <artifactId>spring</artifactId>  
                    </exclusion>  
                </exclusions>  
            </dependency>  
              
            <dependency>  
                <groupId>com.github.sgroschupf</groupId>  
                <artifactId>zkclient</artifactId>  
                <version>0.1</version>  
            </dependency>  
              
            <dependency>  
                <groupId>org.springframework</groupId>  
                <artifactId>spring-core</artifactId>  
                <version>${spring.version}</version>  
            </dependency>  
            <dependency>  
                <groupId>org.springframework</groupId>  
                <artifactId>spring-beans</artifactId>  
                <version>${spring.version}</version>  
            </dependency>  
            <dependency>  
                <groupId>org.springframework</groupId>  
                <artifactId>spring-context</artifactId>  
                <version>${spring.version}</version>  
            </dependency>  
            <dependency>  
                <groupId>org.springframework</groupId>  
                <artifactId>spring-jdbc</artifactId>  
                <version>${spring.version}</version>  
            </dependency>  
            <dependency>  
                <groupId>org.springframework</groupId>  
                <artifactId>spring-web</artifactId>  
                <version>${spring.version}</version>  
            </dependency>  
            <dependency>  
                <groupId>org.springframework</groupId>  
                <artifactId>spring-webmvc</artifactId>  
                <version>${spring.version}</version>  
            </dependency>  
            <dependency>  
                <groupId>org.springframework</groupId>  
                <artifactId>spring-aop</artifactId>  
                <version>${spring.version}</version>  
            </dependency>  
            <dependency>  
                <groupId>org.springframework</groupId>  
                <artifactId>spring-tx</artifactId>  
                <version>${spring.version}</version>  
            </dependency>  
            <dependency>  
                <groupId>org.springframework</groupId>  
                <artifactId>spring-orm</artifactId>  
                <version>${spring.version}</version>  
            </dependency>  
            <dependency>  
                <groupId>org.springframework</groupId>  
                <artifactId>spring-context-support</artifactId>  
                <version>${spring.version}</version>  
            </dependency>  
            <dependency>  
                <groupId>org.springframework</groupId>  
                <artifactId>spring-test</artifactId>  
                <version>${spring.version}</version>  
            </dependency>  
            <dependency>  
                <groupId>org.springframework</groupId>  
                <artifactId>spring-jms</artifactId>  
                <version>${spring.version}</version>  
            </dependency>  
        <dependency>
          <groupId>junit</groupId>
          <artifactId>junit</artifactId>
          <version>3.8.1</version>
          <scope>test</scope>
        </dependency>
      </dependencies>
    </project>

### applicationConsumer.xml ###

<?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://code.alibabatech.com/schema/dubbo"  
        xsi:schemaLocation="http://www.springframework.org/schema/beans  
            http://www.springframework.org/schema/beans/spring-beans.xsd  
            http://code.alibabatech.com/schema/dubbo  
            http://code.alibabatech.com/schema/dubbo/dubbo.xsd ">        
          
        <dubbo:application name="dubbo_consumer" />     
            
        <dubbo:registry  protocol="zookeeper" address="zookeeper://192.168.0.91:2181" />       
            
        <dubbo:reference id="providerService" interface="com.bamboo.service.ProviderService" />  
    </beans>

\#\#\#java  
service

package com.bamboo.service;
    
    public interface  ProviderService {
    
    	public String sayHello(String name);
    }

main

package com.bamboo.dubbo_consumer;
    
    import java.io.IOException;
    
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    
    import com.bamboo.service.ProviderService;
    
    /**
     * dubbo 服务消费端
     * @author bamboo
     *
     */
    public class App 
    {
    	public static void main(String[] args) {  
            ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(  
                    new String[] { "applicationConsumer.xml" });  
              
            context.start();  
            ProviderService providerService = (ProviderService) context.getBean("providerService");  
      
            System.out.println(providerService.sayHello("bamboo"));  
            System.out.println("Press any key to exit.");    
            try {
                System.in.read();  
            } catch (IOException e) {         
                e.printStackTrace();  
            }    
      
        }  
    }

运行

log4j:WARN No appenders could be found for logger (org.springframework.core.env.StandardEnvironment).
    log4j:WARN Please initialize the log4j system properly.
    Hello:bamboo你好，你好~~
    Press any key to exit.

查看监控列表  
![这里写图片描述][SouthEast 4]

### dubboadmin扩展功能 ###

**容错与屏蔽**  
顾名思义就是当服务提供者出现异常时，消费者是否能够正常处理异常返回预想格式服务，防止崩溃信息抛出到客户

**服务降级**  
超时降级 —— 主要配置好超时时间和超时重试次数和机制，并使用异步机制探测恢复情况  
失败次数降级 —— 主要是一些不稳定的API，当失败调用次数达到一定阀值自动降级，同样要使用异步机制探测回复情况  
故障降级 —— 如要调用的远程服务挂掉了（网络故障、DNS故障、HTTP服务返回错误的状态码和RPC服务抛出异常），则可以直接降级  
限流降级 —— 当触发了限流超额时，可以使用暂时屏蔽的方式来进行短暂的屏蔽

**负载均衡**  
dubbo提供了三个基本的负载均衡策略，分别是 随机访问、轮询、最少并发  
[https://blog.csdn.net/qq\_22152261/article/details/80300597][https_blog.csdn.net_qq_22152261_article_details_80300597]

[zookeeper]: http://blog.csdn.net/zjcjava/article/details/78765102
[https_github.com_alibaba_dubbo_releases_tag_dubbo-2.5.7]: https://github.com/alibaba/dubbo/releases/tag/dubbo-2.5.7
[https_github.com_BambooZhang_dubbo-study]: https://github.com/BambooZhang/dubbo-study
[SouthEast]: /images/20220604/5acb03b83c6b45958c4c90f1fc7b2ce4.png
[SouthEast 1]: /images/20220604/9350fcedb6284f1ea74c31c29a6312b4.png
[SouthEast 2]: /images/20220604/fec973f78a8340cbbc15794f6a88c9e6.png
[SouthEast 3]: /images/20220604/674d1dfb266348918f34c8ef7f0d9f2a.png
[SouthEast 4]: /images/20220604/06e81f0db0ab4ebaac3c301a08443a3a.png
[https_blog.csdn.net_qq_22152261_article_details_80300597]: https://blog.csdn.net/qq_22152261/article/details/80300597