【SpringCloud学习笔记】注册中心zookeeper

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SpringCloudzookeeper

服务注册中心zookeeper方案

SpringCloud默认使用Eureka作为注册中心，但是Zookeeper也可以用作替代方案。Zookeeper是分布式协调工具，可以实现注册中心，采用临时节点，和生命周期进行关联，如果服务断开连接，该节点会自动被删除。

前置条件

zookeeper环境搭建

  1. 下载zookeeper

    到apache官网下载zookeeper最新版本（apache-zookeeper-3.6.2），注意下载apache-zookeeper-3.6.2-bin压缩文件。

  2. 解压zookeeper

  3. 创建配置文件

    cp ./conf/zoo_example.cfg ./conf/zoo.cfg

    配置文件：

    tickTime=2000
initLimit=10
syncLimit=5
dataDir=/Users/huzd/Applications/apache-zookeeper-3.6.2/data
clientPort=2181

  4. 启动服务器端

    在bin文件下执行如下命令启动zookeeper

    ./bin/zkServer.sh start

  5. 使用客户端连接

    在bin文件夹下启动zookeeper客户端

    ./bin/zkCli.sh -server 127.0.0.1:2181

实战开发

zk服务提供支付模块

创建项目

创建名为 cloud-provider-payment-8004 的maven项目

修改配置
修改pom.xml文件
   <dependencies>
				<!-- * 其他的省略，重点提出zookeeper的依赖，
             * 其余的依赖请参考cloud-provider-payment-8002
             * 这里可能会有zookeeper版本冲突问题，如果遇到请在下面依赖中排除冲突的版本zookeeper
         -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-zookeeper-discovery</artifactId>
        </dependency>
    </dependencies>
修改application.yml文件

删除eureka的配置，添加如下配置：

spring:
  cloud:
    zookeeper:
      connect-string: 127.0.0.1:2181

添加 /payment/zk 访问路径

    @GetMapping("/zk")
    @ResponseBody
    public Object zk() {
        return "This is from Payment Service of Register :"+port + ",Random String:"+ UUID.randomUUID();
    }
启动程序

日志显示zookeeper已经连接并注册成功

2021-02-25 09:15:43.482  INFO 8220 --- [  restartedMain] org.apache.zookeeper.ZooKeeper           : Initiating client connection, connectString=127.0.0.1:2181 sessionTimeout=60000 watcher=org.apache.curator.ConnectionState@50a4c4cc
2021-02-25 09:15:43.486  INFO 8220 --- [  restartedMain] org.apache.zookeeper.ClientCnxnSocket    : jute.maxbuffer value is 4194304 Bytes
2021-02-25 09:15:43.489  INFO 8220 --- [127.0.0.1:2181)] org.apache.zookeeper.ClientCnxn          : Opening socket connection to server 127.0.0.1/127.0.0.1:2181. Will not attempt to authenticate using SASL (unknown error)
2021-02-25 09:15:43.492  INFO 8220 --- [  restartedMain] o.a.c.f.imps.CuratorFrameworkImpl        : Default schema
2021-02-25 09:15:43.497  INFO 8220 --- [127.0.0.1:2181)] org.apache.zookeeper.ClientCnxn          : Socket connection established, initiating session, client: /127.0.0.1:59183, server: 127.0.0.1/127.0.0.1:2181
2021-02-25 09:15:43.502  INFO 8220 --- [127.0.0.1:2181)] org.apache.zookeeper.ClientCnxn          : Session establishment complete on server 127.0.0.1/127.0.0.1:2181, sessionid = 0x100018816930004, negotiated timeout = 40000
2021-02-25 09:15:43.503  INFO 8220 --- [ain-EventThread] o.a.c.f.state.ConnectionStateManager     : State change: CONNECTED
查看zk注册信息

访问/payment/zk 得到如下界面：

image-20210225094254282

查看zk注册信息

[zk: 127.0.0.1:2181(CONNECTED) 6] ls /
[services, zookeeper]
[zk: 127.0.0.1:2181(CONNECTED) 7] ls /services
[cloud-provider-payment]
[zk: 127.0.0.1:2181(CONNECTED) 8] ls /services/cloud-provider-payment 
[c2fe9f07-8864-4d9b-8bcd-1f7531344d6a]
[zk: 127.0.0.1:2181(CONNECTED) 10] get /services/cloud-provider-payment/c2fe9f07-8864-4d9b-8bcd-1f7531344d6a 
{"name":"cloud-provider-payment","id":"c2fe9f07-8864-4d9b-8bcd-1f7531344d6a","address":"130.30.3.224","port":8004,"sslPort":null,"payload":{"@class":"org.springframework.cloud.zookeeper.discovery.ZookeeperInstance","id":"application-1","name":"cloud-provider-payment","metadata":{"instance_status":"UP"}},"registrationTimeUTC":1614215743754,"serviceType":"DYNAMIC","uriSpec":{"parts":[{"value":"scheme","variable":true},{"value":"://","variable":false},{"value":"address","variable":true},{"value":":","variable":false},{"value":"port","variable":true}]}}

停止payment8004服务查看zk

[zk: 127.0.0.1:2181(CONNECTED) 18] ls /services
[]

zookeeper使用临时节点存储注册信息；服务端停止，zookeeper会立刻删除该节点的注册信息！

当services下面无节点时，在一定时间间隔下services节点也会被删除。

[zk: 127.0.0.1:2181(CONNECTED) 23] ls /   #重启8004服务节点
[services, zookeeper]
[zk: 127.0.0.1:2181(CONNECTED) 24] ls /services 
[cloud-provider-payment]
[zk: 127.0.0.1:2181(CONNECTED) 26] ls /services/cloud-provider-payment #zookeeper中又重新注册了该服务；并且使用了新的ID
[1f211200-7bfe-4fc8-aba8-f1731df2406c]

zk消费者订单模块

创建项目

创建名为 cloud-consumer-order-zk-80 的maven项目

修改配置
修改pom.xml文件
 <dependencies>
        <!-- * 其他的省略，重点提出zookeeper的依赖，
             * 其余的依赖请参考cloud-consumer-order-80
             * 这里可能会有zookeeper版本冲突问题，如果遇到请在下面依赖中排除冲突的版本zookeeper
         -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-zookeeper-discovery</artifactId>
        </dependency>
    </dependencies>
修改application.yml文件
server:
  port: 80

spring:
  application:
    name: cloud-consumer-order-zk-80
  cloud:
    zookeeper:
      connect-string: 127.0.0.1:2181
编写调用程序
@Controller
@RequestMapping("/consumer")
@Slf4j
public class OrderController {

    public static final String PAYMENT_URL = "http://CLOUD-PROVIDER-PAYMENT/";

    @Resource
    RestTemplate restTemplate;

    @GetMapping("/payment/zk")
    @ResponseBody
    public String zk(){
        System.out.println("请求地址："+PAYMENT_URL+"payment/zk");
        return restTemplate.getForObject(PAYMENT_URL+"/payment/zk",String.class);
    }
}
启动程序

查看启动日志；说明消费者order-zk-80已经注册到zk中

2021-02-25 10:09:28.243  INFO 9220 --- [  restartedMain] o.a.c.f.imps.CuratorFrameworkImpl        : Starting
2021-02-25 10:09:28.260  INFO 9220 --- [  restartedMain] org.apache.zookeeper.ZooKeeper           : Initiating client connection, connectString=127.0.0.1:2181 sessionTimeout=60000 watcher=org.apache.curator.ConnectionState@7d8ef487
2021-02-25 10:09:28.269  INFO 9220 --- [  restartedMain] org.apache.zookeeper.ClientCnxnSocket    : jute.maxbuffer value is 4194304 Bytes
2021-02-25 10:09:28.281  INFO 9220 --- [127.0.0.1:2181)] org.apache.zookeeper.ClientCnxn          : Opening socket connection to server 127.0.0.1/127.0.0.1:2181. Will not attempt to authenticate using SASL (unknown error)
2021-02-25 10:09:28.287  INFO 9220 --- [  restartedMain] o.a.c.f.imps.CuratorFrameworkImpl        : Default schema
2021-02-25 10:09:28.303  INFO 9220 --- [127.0.0.1:2181)] org.apache.zookeeper.ClientCnxn          : Socket connection established, initiating session, client: /127.0.0.1:62328, server: 127.0.0.1/127.0.0.1:2181
2021-02-25 10:09:28.313  INFO 9220 --- [127.0.0.1:2181)] org.apache.zookeeper.ClientCnxn          : Session establishment complete on server 127.0.0.1/127.0.0.1:2181, sessionid = 0x100018816930007, negotiated timeout = 40000
2021-02-25 10:09:28.320  INFO 9220 --- [ain-EventThread] o.a.c.f.state.ConnectionStateManager     : State change: CONNECTED
查看zk注册信息
[zk: 127.0.0.1:2181(CONNECTED) 27] ls /services
[cloud-consumer-order-zk-80, cloud-provider-payment]
[zk: 127.0.0.1:2181(CONNECTED) 28] ls /services/cloud-
cloud-consumer-order-zk-80   cloud-provider-payment       
[zk: 127.0.0.1:2181(CONNECTED) 28] ls /services/cloud-consumer-order-zk-80
[6c3a86d2-f0fc-4dee-8a1c-dadd7e66de6e]
[zk: 127.0.0.1:2181(CONNECTED) 29] get /services/cloud-
cloud-consumer-order-zk-80   cloud-provider-payment       
[zk: 127.0.0.1:2181(CONNECTED) 29] get /services/cloud-consumer-order-zk-80/6c3a86d2-f0fc-4dee-8a1c-dadd7e66de6e 
{"name":"cloud-consumer-order-zk-80","id":"6c3a86d2-f0fc-4dee-8a1c-dadd7e66de6e","address":"130.30.3.224","port":80,"sslPort":null,"payload":{"@class":"org.springframework.cloud.zookeeper.discovery.ZookeeperInstance","id":"application-1","name":"cloud-consumer-order-zk-80","metadata":{"instance_status":"UP"}},"registrationTimeUTC":1614218968763,"serviceType":"DYNAMIC","uriSpec":{"parts":[{"value":"scheme","variable":true},{"value":"://","variable":false},{"value":"address","variable":true},{"value":":","variable":false},{"value":"port","variable":true}]}}
[zk: 127.0.0.1:2181(CONNECTED) 30]
访问服务

image-20210225103506470

总结

和Eureka区别是：Zookeeper不用建立注册中心模块，只需要注册自己的模块，就可以调用，因为ZookeeperClient是工具生成的；

使用不同注册中心，接口调用方式不变，无非变化配置文件和maven依赖信息

本文由 huzd 创作，采用 知识共享署名4.0 国际许可协议进行许可本站文章除注明转载/出处外，均为本站原创或翻译，转载前请务必署名最后编辑时间
为: 2021/02/25 10:40

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