Nacos作为服务注册中心

一、官方文档

https://spring.io/projects/spring-cloud-alibaba#learn

 

 

二、基于Nacos的服务提供者

2.1 新建Module

名称为:cloudalibaba-provider-payment9001

 

2.2 改POM

我们在父pom'中已经引入springcloudalibaba 2.1.0 release

本模块的POM

<?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>ckfuture-springcloud</artifactId>
        <groupId>com.ckfuture.springcloud</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>cloudalibaba-provider-payment9001</artifactId>
<dependencies>
   <!--SpringCloud alibaba nacos-->
    <dependency>
        <groupId>com.alibaba.cloud</groupId>
        <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-actuator</artifactId>
    </dependency>

</dependencies>

</project>

2.3 建YML

server:
  port: 9001
spring:
  application:
    name: nacos-payment-provider
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848 #配置Nacos地址
management:
  endpoints:
    web:
      exposure:
        include: '*'

2.4 主启动类

package com.ckfuture.springcloud.alibaba;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

@SpringBootApplication
@EnableDiscoveryClient
public class PaymentMain9001 {
    public static void main(String[] args) {
        SpringApplication.run(PaymentMain9001.class,args);
    }
}

启动nacos,在启动9001生产者,这里我出现个问题,就是在父POM中引用的版本和nacos版本要对应,否则可能出现意外错误。

 

 Nacos版本为:

 

 这样在“服务列表”中可以看到我们的服务名称了。

2.5 业务类

package com.ckfuture.springcloud.alibaba.controller;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

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

    @GetMapping(value = "/payment/nacos/{id}")
    public String getPayment(@PathVariable("id") Integer id){
        return "nacos registry,serverPort:"+serverPort+"\t id"+id;
    }
}

2.6 测试

2.7 在建立一个服务提供者9002

参照9001再建立一个服务提供者,启动后查看nacos,nacos默认带负载均衡。

三、基于Nacos的服务消费者

3.1新建Module

名称为:cloudalibaba-consumer-nacos-order83

3.2改POM

<?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>ckfuture-springcloud</artifactId>
        <groupId>com.ckfuture.springcloud</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>cloudalibaba-consumer-nacos-order83</artifactId>
    <dependencies>
        <!--SpringCloud alibaba nacos-->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>

    </dependencies>

</project>

3.3 建YML

server:
  port: 83
spring:
  application:
    name: nacos-order-consumer
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848
#消费者将要去访问的微服务名称(注册成功进nacos的微服务提供者)
service-url:
  nacos-user-service: http://nacos-payment-provider

3.4 主启动类

package com.ckfuture.springcloud.alibaba;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

@SpringBootApplication
@EnableDiscoveryClient
public class OrderNacosMain83 {
    public static void main(String[] args) {
        SpringApplication.run(OrderNacosMain83.class,args);
    }
}

3.5 业务类

package com.ckfuture.springcloud.alibaba.config;

import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;

@Configuration
public class ApplicationContextConfig {
    /**
     * RestTemplate 通过LoadBalanced注解赋予RestTemplate负载均衡能力 623755606
     * @return
     */
    @Bean
    @LoadBalanced
    public RestTemplate getRestTemplate(){
        return new RestTemplate();
    }
}

 


package com.ckfuture.springcloud.alibaba.controller;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

import javax.annotation.Resource;

@RestController
public class OrderNacosController {
@Resource
private RestTemplate restTemplate;

@Value("${service-url.nacos-user-service}")
private String serverURL;

@GetMapping(value = "/consumer/payment/nacos/{id}")
public String paymentInfo(@PathVariable("id") Long id)
{
return restTemplate.getForObject(serverURL+"/payment/nacos/"+id,String.class);
}
}

3.6 测试

 

 输入地址:http://localhost:83/consumer/payment/nacos/15

 

 

 

 

四、服务注册中心对比

Nacos支持AP和CP模式的切换。

C是所有节点在同一时间看到的数据是一致的;而A的定义是所有的请求都会收到相应。

何时选择使用何种模式?

一般说,如果不需要存储服务级别的信息且服务实例是通过nacos-client注册,并能够保持心跳上报,那么就可以选择AP模式。当前主流的服务如Spring cloud和Dobbo服务,都适用于AP模式,AP模式为了服务的可能性而减弱了一致性,因此AP模式下只支持注册临时实例。

如果需要在服务级别编辑或者存储配置信息,那么CP是必须,K8S服务和DNS服务则适用于CP模式。

CP模式下则支持注册持久化实例,此时则是以Raft协议为集群运行模式,该模式下注册实例之前必须先注册服务,如果服务不存在,则会返回错误。

 

posted @ 2022-01-23 10:36  创客未来  阅读(62)  评论(0编辑  收藏  举报