Sentinel整合Feign对远程调用限流并降级

微服务提供者demo-pay

第一步：创建模块demo-pay添加依赖：

<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>
<!--热部署相关-->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-devtools</artifactId>
</dependency>

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-test</artifactId>
    <scope>test</scope>
</dependency>
<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>

第二步：修改application.yml：

server:
  port: 8801
  servlet:
    context-path: /pay
spring:
  application:
    name: nacos-pay
  cloud:
    nacos:
      discovery:
        server-addr: http://localhost:8848  # 配置Nacos地址
management:
  endpoints:
    web:
      exposure:
        include: '*' # 对外暴露出所有的端点

第三步：项目主启动类添加注解

@EnableDiscoveryClient

第四步：提供控制器PayController：

@RestController
public class PayController {

    @GetMapping("/fun/{id}")
    public String fun(@PathVariable("id") Long id) {
        System.out.println("1111111111111111");
        return "支付 id: " + id;
    }
}

微服务消费者demo-sentinel-openfeign

第一步：创建模块demo-sentinel-openfeign并添加依赖：

<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>
<!--热部署相关-->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-devtools</artifactId>
</dependency>

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-test</artifactId>
    <scope>test</scope>
</dependency>

<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
</dependency>

<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>

<dependency>
    <groupId>com.alibaba.csp</groupId>
    <artifactId>sentinel-datasource-nacos</artifactId>
</dependency>


<!--避免出现警告信息：Spring Cloud LoadBalancer is currently working with the default cache. You can switch to using Caffeine cache, by adding it and org.springframework.cache.caffeine.CaffeineCacheManager to the classpath.-->
<dependency>
    <groupId>com.github.ben-manes.caffeine</groupId>
    <artifactId>caffeine</artifactId>
    <version>3.1.1</version>
</dependency>
<!--  nacos自从2020版本之后不再整合的是Netflix，也就没有ribbon了 -->
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-loadbalancer</artifactId>
    <version>3.0.1</version>
</dependency>

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-openfeign</artifactId>
    <version>3.0.1</version>
</dependency>

第二步：修改application.yml

server:
  port: 6601
  servlet:
    context-path: /sentinelfeign

spring:
  application:
    name: sentinel-feign
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848 # 配置nacos地址
    sentinel:
      transport:
        # 配置sentinel dashboard地址
        dashboard: localhost:8080
        # 默认端口8719，假如被占用会自动从8719开始依次+1扫描，直至找到未被占用的端口
        port: 8719

management:
  endpoints:
    web:
      exposure:
        include: '*' #暴露出所有的端点
# 激活Sentinel对Feign的支持
feign:
  sentinel:
    enabled: true

第三步：在项目主启动类上添加注解：

@EnableFeignClients
@EnableDiscoveryClient

第四步：创建Feign接口：

@Service
//name：指定调用Rest接口所对应的服务名
//path：指定要调用的Rest接口所在的Controller指定的RequestMapping，如果Rest接口所在的Controller没有指定RequestMapping，则不用指定
@FeignClient(name = "nacos-pay", path = "/pay", fallback = PayFeignServiceFallback.class)
public interface PayFeignService {
    @GetMapping("/fun/{id}")
    public String fun(@PathVariable("id") Long id);
}

第五步：创建兜底类：

@Component
public class PayFeignServiceFallback implements PayFeignService {
    @Override
    public String fun(Long id) {
        return "兜底 服务降级： " + id;
    }
}

第六步：创建测试Controller

@RestController
public class DemoCtroller {
    @Resource
    private PayFeignService payFeignService;

    @GetMapping("/fun1")
    public String fun1(Long a) {
        String res = payFeignService.fun(a);
        return "fun1 "+res;
    }
}

测试：

第一步：依次启动软件Nacos和Sentinel，然后再分别启动项目demo-pay和demo-sentinel-openfeign。

第二步：结果：

添加流控规则：

请求消费者中的示例控制器中的api接口： 低频访问：

高频访问：