The building had been registry cluster, load balancing

 
问题：微服务RPC远程服务调用最核心的是什么 
       高可用,试想你的注册中心只有一个only one, 它出故障了那就呵呵(￣▽￣)"了,会导致整个为服务环境不可用,所以
 
　　解决办法：搭建Eureka注册中心集群 ,实现负载均衡+故障容错 

集群代码：

修改host文件 

Set up twoEureka服务中心,端口号分别为7001 7002

7001yml文件：

server:
  port: 7001

eureka:
  instance:
    hostname: eureka7001.com #eureka服务端的实例名称
  client:
    register-with-eureka: false     #false表示不向注册中心注册自己.
    fetch-registry: false     #false表示自己端就是注册中心,我的职责就是维护服务实例,并不需要去检索服务
    service-url:
      defaultZone: http://eureka7002.com:7002/eureka/

 7002yml文件：

server:
  port: 7002

eureka:
  instance:
    hostname: eureka7002.com #eureka服务端的实例名称
  client:
    register-with-eureka: false     #false表示不向注册中心注册自己.
    fetch-registry: false     #false表示自己端就是注册中心,我的职责就是维护服务实例,并不需要去检索服务
    service-url:
      defaultZone: http://eureka7001.com:7001/eureka/

 7001启动类：

@SpringBootApplication
@EnableEurekaServer
public class EurekaMain7001
{
    public static void main(String[] args)
    {
        SpringApplication.run(EurekaMain7001.class,args);
    }
}

7002启动类 ：

@SpringBootApplication
@EnableEurekaServer
public class EurekaMain7002
{
    public static void main(String[] args)
    {
        SpringApplication.run(EurekaMain7002.class,args);
    }
}

 Load balancing implementation code：

假设现在80端口对外暴露,通过Eureka调用8001 8002的端口服务（负载均衡,Business is the same between）

 8001的yml文件

server:
  port: 8001

spring:
  application:
    name: cloud-payment-service
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource            # 当前数据源操作类型
    driver-class-name: com.mysql.cj.jdbc.Driver             # mysql驱动包
    url: jdbc:mysql://localhost:3306/2019db?useSSL=true&useUnicode=true&characterEncoding=UTF-8&serverTimezone=UTC
    username: root
    password: newroot

mybatis:
  mapperLocations: classpath:mapper/*.xml
  type-aliases-package: com.lun.springcloud.entities    # 所有Entity别名类所在包
eureka:
  client:
    #表示是否将自己注册进EurekaServer默认为true.
    register-with-eureka: true
    #是否从EurekaServer抓取已有的注册信息,默认为true.单节点无所谓,集群必须设置为true才能配合ribbon使用负载均衡
    fetchRegistry: true
    service-url:
      defaultZone: http://eureka7001.com:7001/eureka,http://eureka7002.com:7002/eureka  # 集群版
#      defaultZone: http://localhost:7001/eureka

  8002的yml文件

server:
  port: 8002

spring:
  application:
    name: cloud-payment-service
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource            # 当前数据源操作类型
    driver-class-name: com.mysql.cj.jdbc.Driver             # mysql驱动包
    url: jdbc:mysql://localhost:3306/2019db?useSSL=true&useUnicode=true&characterEncoding=UTF-8&serverTimezone=UTC
    username: root
    password: newroot

mybatis:
  mapperLocations: classpath:mapper/*.xml
  type-aliases-package: com.lun.springcloud.entities    # 所有Entity别名类所在包
eureka:
  client:
    #表示是否将自己注册进EurekaServer默认为true.
    register-with-eureka: true
    #是否从EurekaServer抓取已有的注册信息,默认为true.单节点无所谓,集群必须设置为true才能配合ribbon使用负载均衡
    fetchRegistry: true
    service-url:
      defaultZone: http://eureka7001.com:7001/eureka,http://eureka7002.com:7002/eureka  # 集群版
#      defaultZone: http://localhost:7001/eureka

 8001启动类

@SpringBootApplication
@EnableEurekaClient
public class PaymentMain8001
{
    public static void main(String[] args)
    {
        SpringApplication.run(PaymentMain8001.class,args);
    }
}

8002启动类

@SpringBootApplication
@EnableEurekaClient
public class PaymentMain8002
{
    public static void main(String[] args)
    {
        SpringApplication.run(PaymentMain8002.class,args);
    }
}

 8001 8002 The business processing part（片段）（Is part of the increase and delete the databasemybatis）

@RestController
@Slf4j
@ResponseBody
public class PaymentController {

    @Value("${server.port}")
    private  String serverPort;

    @Resource
    private PaymentService paymentService;
    @PostMapping("/payment/create")
    public CommonResult create(@RequestBody Payment payment)
    {
        int result = paymentService.create(payment);
        log.info("***********插入成功"+result+"服务端口"+serverPort);
        if(result>0){
            return  new CommonResult(200,"插入数据成功",result);
        }else {
            return new CommonResult(444,"插入失败",null);
        }
    }

    @GetMapping("/payment/get/{id}")
    public CommonResult get(@PathVariable("id") Long id)
    {
        System.out.println(id+"********&*&*&*&*");
        Payment payment = paymentService.getPayment(id);
        log.info("查询结果"+payment+"服务端口"+serverPort);
        if(payment!=null)
        {
            return  new CommonResult(200,"查询数据成功",payment);
        }else {
            return  new CommonResult(444,"没有该记录",null);
        }
    }
}

80端口yml文件 

server:
  port: 80
spring:
  application:
    name: cloud-order-service

eureka:
  client:
    #表示是否将自己注册进EurekaServer默认为true.
    register-with-eureka: true
    #是否从EurekaServer抓取已有的注册信息,默认为true.单节点无所谓,集群必须设置为true才能配合ribbon使用负载均衡
    fetchRegistry: true
    service-url:
      defaultZone: http://eureka7001.com:7001/eureka,http://eureka7002.com:7002/eureka  # 集群版
#      defaultZone: http://localhost:7001/eureka

 80端口启动类

@Configuration
public class ApplicationContextConfig {

    @Bean
    @LoadBalanced //使用@LoadBalanced注解赋予RestTemplate负载均衡的能力
    public RestTemplate restTemplate()
    {
        return new RestTemplate();
    }
}

80Port business class 

@RestController
@Slf4j
public class orderController {
//    public static final String PaymentSrv_URL = "http://localhost:8001";
public static final String PAYMENT_SRV = "http://CLOUD-PAYMENT-SERVICE";
    @Autowired
    private RestTemplate restTemplate;

    @GetMapping("/consumer/payment/create") //客户端用浏览器是get请求,但是底层实质发送post调用服务端8001
    public CommonResult create(Payment payment)
    {
        System.out.println("**********");
        return restTemplate.postForObject(PAYMENT_SRV + "/payment/create",payment,CommonResult.class);
    }


    @GetMapping("/consumer/payment/get/{id}")
    public CommonResult getPayment(@PathVariable Long id)
    {
        return restTemplate.getForObject(PAYMENT_SRV + "/payment/get/"+id, CommonResult.class, id);
    }

结果：

发送请求：http://localhost/consumer/payment/get/31

第一次：

第二次：

服务端口号为8001