Zookeeper服务注册与发现

什么是Zookeeper？

Zookeeper是一个分布式协调工具,可以实现注册中心功能

（官方解释）ZooKeeper是用于维护配置信息，命名，提供分布式同步以及提供组服务的集中式服务。所有这些类型的服务都以某种形式被分布式应用程序使用。每次实施它们时，都会进行很多工作来修复不可避免的错误和竞争条件。由于难以实现这类服务，因此应用程序最初通常会跳过它们，这会使它们在发生更改时变得脆弱并且难以管理。即使部署正确，这些服务的不同实现也会导致管理复杂。

安装Zookeeper（linux）

https://blog.csdn.net/she_lock/article/details/80435176

使用Zookeeper实现注册中心功能的步骤

新建cloud-provider-payment8004

pom

    <dependencies>
        <!--        引入公共模块-->
        <dependency>
            <groupId>org.example</groupId>
            <artifactId>cloud-api-commons</artifactId>
            <version>${project.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--SpringBoot整合Zookeeper客户端-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-zookeeper-discovery</artifactId>
            <exclusions>
                <!--先排除自带的zookeeper3.5.3-->
                <exclusion>
                    <groupId>org.apache.zookeeper</groupId>
                    <artifactId>zookeeper</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <!--添加zookeeper3.4.9版本-->
        <dependency>
            <groupId>org.apache.zookeeper</groupId>
            <artifactId>zookeeper</artifactId>
            <version>3.4.14</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>
</project>

yaml

server:
  port: 8004

spring:
  application:
    name: cloud-provider-payment #微服务名称
    #zookeeper的配置
  cloud:
    zookeeper:
      connect-string: 116.62.102.168:2181

主启动类

@SpringBootApplication
@EnableDiscoveryClient
public class PaymentMain8004 {
    public static void main(String[] args) {
        SpringApplication.run(PaymentMain8004.class,args);
    }
}

controller

@RestController
@Slf4j
public class PaymentController {
    @Value("${server.port}")
    private String serverPort;

    @RequestMapping(value = "payment/zk")
    public String paymentZk() {
        return "SpringCloud with zookeeper:" + serverPort + "\t" + UUID.randomUUID().toString();
    }
}

启动测试注册，注意如果你的依赖是spring-cloud-starter-zookeeper-discovery那么这个依赖是自带最新版的zookeeper所以可能会造成依赖不兼容的问题并且会爆出

解决方案就是排除他原本带的版本，更换成我们自己版本匹配的依赖，具体操作如下：

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-zookeeper-discovery</artifactId>
    <exclusions>
        <!--先排除自带的zookeeper3.5.3-->
        <exclusion>
            <groupId>org.apache.zookeeper</groupId>
            <artifactId>zookeeper</artifactId>
        </exclusion>
    </exclusions>
</dependency>
<!--添加zookeeper3.4.9版本-->
<dependency>
    <groupId>org.apache.zookeeper</groupId>
    <artifactId>zookeeper</artifactId>
    <version>3.4.14</version>
</dependency>