1、添加依赖

		<dependency>
			<groupId>com.alibaba.cloud</groupId>
			<artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-actuator</artifactId>
		</dependency>
		<dependency>
			<groupId>com.alibaba.csp</groupId>
			<artifactId>sentinel-web-servlet</artifactId>
		</dependency>

2、下载sentinel dashboard

首先，查看spring-cloud-starter-alibaba-sentinel依赖添加的sentinel-core的版本号

可以看到sentinel-core的版本号是1.7.1，所以 sentinel dashboard的版本号也要是1.7.1，所以本案例下载 1.7.1的dashboard

下载地址：

https://github.com/alibaba/Sentinel/releases

下载下来的jar包是： sentinel-dashboard-1.7.1.jar

使用java -jar sentinel-dashboard-1.7.1.jar 启动dashboard

java -jar sentinel-dashboard-1.7.1.jar

3、添加配置

添加spring.cloud.sentinel.transport.dashboard 和management.endpoints.web.exposure.include配置，如下：

spring:
  application:
    name: say
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848
        namespace: b62b1132-d8c6-4740-b745-75bcfb4f66a5
        cluster-name: GD
    sentinel:
      transport:
        dashboard: localhost:8080
logging:
  config: classpath:log4j2.xml
server:
  port: 8091
feign:
  client:
    config:
      helloworld:
        loggerLevel: full
management:
  endpoints:
    web:
      exposure:
        include: '*'

4、添加FilterContextConfig 配置，如果不添加 链路流控模式会不生效

package com.codex.terry.configuration;

import com.alibaba.csp.sentinel.adapter.servlet.CommonFilter;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class FilterContextConfig {
	/**
     * @NOTE 在spring-cloud-alibaba v2.1.1.RELEASE及前，sentinel1.7.0及后，关闭URL PATH聚合需要通过该方式，spring-cloud-alibaba v2.1.1.RELEASE后，可以通过配置关闭：spring.cloud.sentinel.web-context-unify=false
     * 手动注入Sentinel的过滤器，关闭Sentinel注入CommonFilter实例，修改配置文件中的 spring.cloud.sentinel.filter.enabled=false
     * 入口资源聚合问题：https://github.com/alibaba/Sentinel/issues/1024 或 https://github.com/alibaba/Sentinel/issues/1213
     * 入口资源聚合问题解决：https://github.com/alibaba/Sentinel/pull/1111
     */
    @Bean
    public FilterRegistrationBean sentinelFilterRegistration() {
        FilterRegistrationBean registration = new FilterRegistrationBean();
        registration.setFilter(new CommonFilter());
        registration.addUrlPatterns("/*");
        // 入口资源关闭聚合
        registration.addInitParameter(CommonFilter.WEB_CONTEXT_UNIFY, "false");
        registration.setName("sentinelFilter");
        registration.setOrder(1);
        return registration;
    }
}

5、打开 sentinel dashboard进行流控、降级等配置

http://localhost:8080/