Dubbo + Zookeeper 搭建微服务项目
项目搭建基本步骤
- （一）搭建注册中心Zookeeper
- （二）定义公共接口
- （三）服务提供者
-
-
- 1. 配置 pom.xml 文件
- 2. 配置 application.yml
- 3. 接口实现类
- 4. 主启动类
-
- （四）服务消费者
-
-
- 1. 配置 pom.xml 文件
- 2. 配置 application.yml
- 3. 控制层
- 4. 主启动类
-
- （五）验证
- （六）dubbo-admin搭建
-
-
- 1. 拉取镜像
- 2. 启动dubbo-admin容器
- 3. 登录管理平台
- 4. 问题记录
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- （七）高级使用
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- 7.1 负载均衡
-
-
- 7.1.1 负载均衡接口
- 7.1.2 自定义负载均衡策略
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-
（一）搭建注册中心Zookeeper
- 从官网下载 Zookeeper ，Zookeeper 下载地址
- 使用 docker 启动 Zookeeper 容器
# 拉取镜像
docker pull zookeeper:3.8.0
# 运行容器
docker run --name zookeeper -p 2181:2181 --restart always -d zookeeper:3.8.0
（二）定义公共接口
public interface HelloService {
String hello(String name);
}
（三）服务提供者
1. 配置 pom.xml 文件
<?xml version="1.0" encoding="UTF-8"?>
<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">
<parent>
<artifactId>dubbo-demo</artifactId>
<groupId>com.coffee</groupId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>dubbo-provider</artifactId>
<properties>
<dubbo-version>3.0.0</dubbo-version>
</properties>
<dependencies>
<dependency>
<groupId>com.coffee</groupId>
<artifactId>common-api</artifactId>
<version>${project.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<!--dubbo配置-->
<dependency>
<groupId>org.apache.dubbo</groupId>
<artifactId>dubbo-spring-boot-starter</artifactId>
<version>${dubbo-version}</version>
</dependency>
<dependency>
<groupId>org.apache.dubbo</groupId>
<artifactId>dubbo-registry-zookeeper</artifactId>
<version>${dubbo-version}</version>
</dependency>
<dependency>
<groupId>org.apache.dubbo</groupId>
<artifactId>dubbo-configcenter-zookeeper</artifactId>
<version>${dubbo-version}</version>
</dependency>
<dependency>
<groupId>org.apache.dubbo</groupId>
<artifactId>dubbo-metadata-report-zookeeper</artifactId>
<version>${dubbo-version}</version>
</dependency>
<dependency>
<groupId>org.apache.dubbo</groupId>
<artifactId>dubbo-config-spring</artifactId>
<version>${dubbo-version}</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
2. 配置 application.yml
server:
port: 6060
dubbo:
application:
name: dubbo-provider
protocol:
name: dubbo
port: 20880
registry:
id: zk-registry
address: zookeeper://127.0.0.1:2181
config-center:
address: zookeeper://127.0.0.1:2181
metadata-report:
address: zookeeper://127.0.0.1:2181
3. 接口实现类
@DubboService
public class HelloServiceImpl implements HelloService {
@Override
public String hello(String name) {
return "Hello " + name + ", This is Dubbo + Zookeeper !";
}
}
4. 主启动类
@SpringBootApplication
@EnableDubbo
public class DubboProviderApplication {
public static void main(String[] args) {
SpringApplication.run(DubboProviderApplication.class, args);
}
}
（四）服务消费者
1. 配置 pom.xml 文件
<?xml version="1.0" encoding="UTF-8"?>
<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">
<parent>
<artifactId>dubbo-demo</artifactId>
<groupId>com.coffee</groupId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>dubbo-consumer</artifactId>
<properties>
<dubbo-version>3.0.0</dubbo-version>
</properties>
<dependencies>
<dependency>
<groupId>com.coffee</groupId>
<artifactId>common-api</artifactId>
<version>${project.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<!--dubbo配置-->
<dependency>
<groupId>org.apache.dubbo</groupId>
<artifactId>dubbo-spring-boot-starter</artifactId>
<version>${dubbo-version}</version>
</dependency>
<dependency>
<groupId>org.apache.dubbo</groupId>
<artifactId>dubbo-registry-zookeeper</artifactId>
<version>${dubbo-version}</version>
</dependency>
<dependency>
<groupId>org.apache.dubbo</groupId>
<artifactId>dubbo-configcenter-zookeeper</artifactId>
<version>${dubbo-version}</version>
</dependency>
<dependency>
<groupId>org.apache.dubbo</groupId>
<artifactId>dubbo-metadata-report-zookeeper</artifactId>
<version>${dubbo-version}</version>
</dependency>
<dependency>
<groupId>org.apache.dubbo</groupId>
<artifactId>dubbo-config-spring</artifactId>
<version>${dubbo-version}</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
2. 配置 application.yml
server:
port: 8686
dubbo:
application:
name: dubbo-consumer
protocol:
name: dubbo
port: 20880
registry:
id: zk-registry
address: zookeeper://127.0.0.1:2181
config-center:
address: zookeeper://127.0.0.1:2181
metadata-report:
address: zookeeper://127.0.0.1:2181
3. 控制层
@RestController
public class ConsumerController {
@DubboReference
private HelloService helloService;
@RequestMapping(value = "/hello",method = RequestMethod.GET)
public String hello(@RequestParam("name") String name){
return helloService.hello(name);
}
}
4. 主启动类
@SpringBootApplication
@EnableDubbo
public class DubboConsumerApplication {
public static void main(String[] args) {
SpringApplication.run(DubboConsumerApplication.class, args);
}
}
（五）验证
- 分别启动服务的提供者和消费者
- 访问 http://localhost:8686/hello?name=Dubbo，页面显示（Hello Dubbo, This is Dubbo + Zookeeper !）则项目搭建成功
（六）dubbo-admin搭建
1. 拉取镜像
docker pull apache/dubbo-admin:0.4.0
2. 启动dubbo-admin容器
docker run -p 8888:8080 --name dubbo-admin \
-e admin.registry.address=zookeeper://127.0.0.1:2181 \
-e admin.config-center=zookeeper://127.0.0.1:2181 \
-e admin.metadata-report.address=zookeeper://127.0.0.1:2181 \
--restart=always \
-d apache/dubbo-admin:0.4.0
3. 登录管理平台
访问 http://127.0.0.1:8888，并使用账号与密码登录（默认账号与密码都是root）
4. 问题记录
a、访问 http://127.0.0.1:8888 如果出现无法访问或者查看 dubbo-admin 容器日志显示无法连接上 zookeeper，那么执行以下步骤：
- docker inspect --format=‘{{.NetworkSettings.IPAddress}}’ [zookeeper容器ID]，获取 zookeeper 容器的 IPAddress
- 用该 IPAddress 数值替换启动 dubbo-admin 容器命令 中的 127.0.0.1，然后重新启动 dubbo-admin容器
b、查看zookeeper产生的日志，ZooKeeper的日志是序列化过的，所以需要反序列化。
# ZooKeeper 3.6版本及之后的版本，可使用该命令
zkTxnLogToolkit.sh -d 日志文件名
（七）高级使用
7.1 负载均衡
Dubbo 负载均衡策略支持用户自定义拓展，内置默认的负载均衡算法为“random”，内置五种负载均衡算法分别为：
- random：随机，按照权重设置随机概率
- roundrobin：轮询，按公约后的权重设置轮询比例
- leastactive：最少活跃数，如果活跃数相同则随机调用，活跃数指调用前后计数差
- consistenthash：一致性哈希，相同参数的请求总是发送到同一个提供者
- shortestresponse：基于响应的时间进行计算，过滤成功调用响应时间最短的调用者数量，统计这些调用者的权重和数量（dubbo 2.7.7之后新增）
7.1.1 负载均衡接口
@SPI(RandomLoadBalance.NAME)
public interface LoadBalance {
/**
* select one invoker in list.
* @param invokers invokers.
* @param url refer url
* @param invocation invocation.
* @return selected invoker.
*/
@Adaptive("loadbalance")
<T> Invoker<T> select(List<Invoker<T>> invokers, URL url, Invocation invocation) throws RpcException;
}
7.1.2 自定义负载均衡策略
- 继承 AbstractLoadBalance
public class CustomizeLoadBalanceRule extends AbstractLoadBalance {
private AtomicInteger count = new AtomicInteger(0);
@Override
protected <T> Invoker<T> doSelect(List<Invoker<T>> invokers, URL url, Invocation invocation) {
int index = count.incrementAndGet() % invokers.size();
return invokers.get(index);
}
}
- 配置文件
在resource目录下，创建 META-INF/dubbo 目录，并创建名称为org.apache.dubbo.rpc.cluster.LoadBalance的文件，内容（key，value）形式，key自定义，value为自定义类的权限定类名。比如customize=com.huaweicloud.sample.config.CustomizeLoadBalanceRule
3. 使用自定义负载均衡
@DubboReference(loadbalance = "customize")
private HelloService helloService;