Spring Cloud Alibaba Sentinel 高可用防护

1.导言

服务级联调用：当服务A故障时，服务B调用失败，但还会一直重试。高并发的情况下，会有很多服务B的线程调用服务A，每个线程都会阻塞等待，直到超时，积累到一定程度后，服务B也会崩溃，变为不可用。同样的道理，上游的服务C也会奔溃，变为不可用，这样产生了服务级联调用的雪崩，导致系统整体不可用。所以我们需要一套完善的机制，来保护系统，例如限流，熔断降级，防止服务被压垮，防止发生系统雪崩，阿里的Sentinel就是一套成熟的防护体系，就像一个哨兵一样，时刻保护我们的系统。

Sentinel 的用法很简单，服务只需要添加 Sentinel 的依赖，就具有限流、降级等防护功能了。但具体如何防护呢？，例如希望此服务的某个接口的 QPS 达到 5 时就限流，这就需要设定一个 Sentinel 规则。有了规则之后，Sentinel 便会根据规则来保护服务。那么规则怎么设置呢？手写肯定不现实，Sentinel 提供了一个管理控制台，界面化设置规则，规则会被自动推送给服务。

2.服务整合

服务添加 Sentinel 依赖

<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-actuator</artifactId>
  </dependency>
  <!--sentinel 自己的依赖-->
 <dependency> 
  <groupId>com.alibaba.cloud</groupId>
  <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId> 
</dependency>

开启属性配置

management:
 endpoints:
   web:
    exposure:
      include: '*'

访问 Sentinel 端点信息：如果能访问成功，就已经是整合成功了。

http://localhost:8001/actuator/sentinel

3.搭建 Sentinel 控制台

下载编译源码

https://github.com/alibaba/Sentinel

编译源码

cd sentinel-dashboard
mvn clean package

启动成功端口是8080，默认帐号密码 sentinel，因为sentinel 是懒加载，所以第一次是空的。

java -jar sentinel-dashboard-1.7.0.jar

服务整合控制台

spring:
 application:
   name: service-provider
cloud:
  sentinel:
    transport:
      dashboard: localhost:8080

4.URL限流与资源限流

URL限流比较好理解，就是根据访问路径进行限流控制。例如有一个接口：/user/get，就可以对其添加限流规则。“资源”是 Sentinel 中的重要概念，可以被调用的都可以视为资源，例如接口、Service。对资源设置一个名称，就可以对其添加限流规则。

流控效果验证

快速多几次访问 /hello 这个接口。因为设置的限流是 QPS 阈值为 1，所以很容易触发限流规则。

流控规则项说明：

资源名：这里默认使用的接口地址
针对来源：可以指定来自哪个服务的请求才适用这条规则，默认是default，也就相当于不区分来源
阈值类型：可以根据 QPS，也就是每秒请求数，进行设置，也可以根据已经使用的线程数来设置
单机阈值：设置此限流规则的阈值数。例如阈值类型选择了 QPS，阈值设置为1，意思就是当每秒请求数达到 1 以后就限流，阈值类型如果选择了线程数，意思就是处理请求的线程数达到 1 以上就限流。
流控模式：直接，就是针对这个接口本身
流控效果：快速失败，直接失败，抛异常

根据资源进行限流

对一个测试接口设置为资源，在 Sentinel Console 中对其设置限流规则，验证限流生效。

@GetMapping("/hello")
@SentinelResource(value = "res_hello")
public String hello(@RequestParam String name) {
  return "hello " + name + "!";
}

在 Console 中添加测试接口的限流规则

与之前的对 URL 添加流控规则的界面一致。只是“资源名”这项不再是接口的 URL，变成了我们定义的资源名。验证方式和被限流后的效果都与之前URL方式一致。

5.关联限流与链路限流

假设一个 Service 中有2个接口：查询、修改。当查询接口访问量特别大时，必然要影响修改接口，可能会导致修改接口无法处理请求。如果业务上，修改功能优先于查询功能，这就出现了一种限流的需求：“当修改接口的访问量达到一定程度时，就对查询接口限流”。这就是“关联限流”，限流规则不是自己设置的，而是被别人影响的。

持续大量访问 /hi 接口，使其触发阈值例如通过脚本持续访问 /hi :

while true; 
do curl -X GET "http://localhost:8001/hi?name=a" ;
done;

访问接口 /hello，应已经被限流，相当是hi接口访问量特别高的时候，hello接口被限流了。

这个微服务中，2个API都需要调用这个Service资源，需要做限流保护。如果查询接口请求多，导致这个资源被限流，那么修改接口也就用不了了，很冤枉。这就出现了一种限流的需求：“这个Service资源只对查询接口限流，不影响修改接口”。这就是“链路限流”，执行限流时要判断流量是从哪儿来的。

创建2个测试接口（/testa，/testb），都调用同一个Service（设置为 SentinelResource）。在 Sentinel Console 中对Service设置限流规则，指定入口资源为 /testa。验证 /testa 被限流时，/testb 正常。

package com.example.demo;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class TestController {
    @Autowired
    private CommonService commonService;

    @GetMapping("/testa")
    public String testa() {
        return "test a : " + commonService.getName();
    }
    @GetMapping("/testb")
    public String testb() {
        return "test b : " + commonService.getName();
    }

}

构建2个测试接口，1个Service，指定其为 SentinelResource，2个接口都调用此Service

package com.example.demo;

import com.alibaba.csp.sentinel.annotation.SentinelResource;
import org.springframework.stereotype.Service;

@Service
public class CommonService {
    @SentinelResource("getName")
    public String getName(){
        return "dell";
    }
}

Sentinel Console 中对Service设置链路限流，入口资源指定 /testa

注意点版本有问题。

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Greenwich.SR5</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>2.1.1.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

6.预热与排队等待

预热限流

秒杀开始！海量用户同时请求购买接口。这一瞬间冲击非常大，即使接口设置了限流阈值，一瞬间打满也是很危险的。在秒杀开始之前，这个接口的请求量是比较少的，由空闲状态切换为繁忙状态，我们希望这个过程是逐步的，而不是突然的。这种场景就需要使用“预热 Warm Up”的流控方式。

假设有个接口的特点是间歇性突发流量，在某一秒有大量的请求到来，而接下来的几秒则处于空闲状态，属于时忙时闲。正常限流方式会导致大量请求被丢弃。我们希望系统能够在接下来的空闲期间逐渐处理这些请求，而不是在第一秒直接拒绝超出阈值的请求。这种场景就需要使用“排队等待”的流控方式。

预热的处理机制：

预热流控会设置一个初始阈值，默认是设置阈值的 1/3，在经过预期的时间后，达到设置的阈值。例如设置：阈值=10，预期时间=10秒。则初始阈值为 3，10秒内，阈值逐步增加，10秒后增加到10。使用的是令牌桶算法。

创建一个项目，构建1个测试接口

package com.example.demo;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class TestController {
    @GetMapping("/hi")
    public String hi(){
        return "hi
";
    }
}

集成 Sentinel 与 Sentinel Console

Sentinel Console 中对接口设置预热 Warm Up 限流，阈值设为 10 QPS，预热时间设为 10 秒

排队等待

排队等待的处理机制：
此方式会严格控制请求通过的间隔时间，让请求以均匀的速度通过，对应的是漏桶算法。例如阈值 QPS = 2，那么就是 500ms 才允许通过下一个请求。

构建1个测试接口

Sentinel Console 中对接口设置“排队等待”限流，阈值设为 1 QPS，超时时间设为 1000 毫秒，超时时间是指每个队列最长的等待时间

持续访问 /hello 接口，会看到匀速通过的效果，例如通过脚本持续访问 /hello :

while true; 
do curl -X GET "http://localhost:8001/hello?name=a" ;
done;

7.热点限流与系统限流

/product/query?id=1&name=phone&price=100
这个API中包括3个参数，假设其中“name”参数是使用最多的，这个接口的绝大部分请求都含有“name”参数，可以称其为“热点参数”。我们可以针对这个热点参数设置接口的限流，当请求带有此参数时，如果达到阈值就触发限流，否则不限流。

热点规则机制

@GetMapping("hotparam")
@SentinelResource(value = "hotparam")
public String hotparam(String type, String name){ ... }

参数索引从0开始，按照接口中声明的顺序，此例子中“0”指“type”，“1”指“name”。可以对资源 hotparam 设置热点限流，例如参数 0 的阈值为 1，窗口时长 1秒，一旦在时间窗口内，带有指定索引的参数的 QPS 达到阈值后，会触发限流。还可以对此参数的值进行特殊控制，例如参数值为“5”或者“10”时的阈值，根据值独立控制阈值。

点击新增热点规则，选择高级选项

注意：
热点限流只支持“QPS 限流模式”
针对参数值时，参数类型必须是基本类型（byte int long float double boolean char）或者 String

系统限流

之前的限流规则都是针对接口资源的，如果每个资源的阈值都没有达到，但系统能力不足了怎么办？所以，我们需要针对系统情况来设置一定的规则，系统保护规则是应用整体维度的，而不是资源维度的。
系统保护规则是从应用级别的入口流量进行控制，从单台机器的 load、CPU 使用率、平均 RT、入口 QPS 和并发线程数等几个维度监控应用指标，让系统尽可能跑在最大吞吐量的同时保证系统整体的稳定性。

系统规则模式
Load 自适应（仅对 Linux/Unix-like 机器生效）：系统的 load1 作为限流指标，进行自适应系统保护。当
系统 load1 超过设定的阈值，且系统当前的并发线程数超过估算的系统容量时才会触发系统保护。
系统容量由系统的 maxQps * minRt 估算得出。
设定参考值： CPU cores * 2.5。
CPU 使用率：当系统 CPU 使用率超过阈值即触发系统保护（取值范围 0.0-1.0），比较灵敏。
平均 RT：当单台机器上所有入口流量的平均 RT 达到阈值即触发系统保护，单位是毫秒。
并发线程数：当单台机器上所有入口流量的并发线程数达到阈值即触发系统保护。
入口 QPS：当单台机器上所有入口流量的 QPS 达到阈值即触发系统保护。

系统规则设置界面

RT 效果验证

1. 阈值设置为 10
2. 持续访问接口 /test-a（其中有睡眠时间），应看到限流的效果。例如通过脚本持续访问 /test-a :

while true; 
do curl -X GET "http://localhost:8001/test-a";
done;

入口QPS 效果验证：
1. 阈值设置为 3
2. 批量持续访问3个测试接口，应看到限流的效果

并发线程数效果验证：

阈值设置为 3

编写多线程测试代码访问接口，应看到限流效果

package com.example.demo;

import org.springframework.web.client.RestTemplate;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class TestThread {
    public static void main(String[] args) {
        // 定义一个线程池
        // 创建一个 RestTemplate
        // 循环启动线程发送请求

        RestTemplate restTemplate = new RestTemplate();
        ExecutorService executorService = Executors.newFixedThreadPool(10);
        for (int i= 0; i< 50; i++){
            executorService.submit(() -> {
                try{
                    System.out.println(restTemplate.getForObject("http://localhost:8081/hi", String.class));
                }catch (Exception e){
                    System.out.println("exception: " + e.getMessage());
                }
            });
        }
    }
}

8.降级规则

除了流量控制以外，对调用链路中不稳定的资源进行熔断降级也是保障高可用的重要措施之一。Sentinel 熔断降级会在调用链路中某个资源不正常时，对这个资源的调用进行限制，让请求快速失败，避免导致级联错误。当资源被降级后，在接下来的降级时间窗口之内，对该资源的调用都自动熔断。

RT 降级策略

创建测试接口

@GetMapping("/degrade-rt")
public String test_degrade_rt(){
try { Thread.sleep(200); } catch (InterruptedException e) { e.printStackTrace(); }
    return "ok";
}

设置降级规则，阈值 1ms，时间窗口 3秒

持续请求“/degrade-rt”，应显示降级效果

while true; 
do curl -X GET "http://localhost:8081/degrade-rt";
done;

异常比例降级策略

降级规则设置界面 0.1就是百分之十，时间窗口60秒，每秒错误百分之10 就会开始降级策略直到时间窗口结束。

创建测试接口

@GetMapping("/degrade-exception-rate")
public String test_degrade_exception_rate() throws Exception {
throw new Exception("rate");
}

持续请求“/degrade-exception-rate”，应显示降级效果

while true; 
do curl -X GET "http://localhost:8081/degrade-exception-rate";
done;

异常数降级策略

降级规则设置界面在一分钟内异常数大于三次，就会被熔断降级直到时间窗口结束

创建测试接口

@GetMapping("/degrade-exception-num")
public String test_degrade_exception_num() throws Exception {
throw new Exception("rate");
}

持续请求“/degrade-exception-num”，应显示降级效果

while true; 
do curl -X GET "http://localhost:8001/degrade-exception-num";
done;

9.RestTemplate 与 Feign 整合 Sentinel

服务会调用其他服务，调用方式常用的是 RestTemplate 与 Feign，对于 Sentinel 来讲他们都是可以被保护的资源，所以我们需要学习一下 RestTemplate 与 Feign 如何与 Sentinel 整合，还有如何处理限流与降级后的异常。

整合流程

服务消费者添加依赖

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

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

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

添加配置

server:
  port: 8082
spring:
  application:
    name: service-consumer
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848
    sentinel:
      transport:
        dashboard: localhost:8080
management:
  endpoints:
    web:
      exposure:
        include: '*'

@Configuration
public class ConsumerConfig {
    @Bean
    @SentinelRestTemplate
    public RestTemplate restTemplate() {
        return new RestTemplate();
    }
}

RestTemplate 限流与降级异常处理

定义异常处理类

package com.example.demo;

import com.alibaba.cloud.sentinel.rest.SentinelClientHttpResponse;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import org.springframework.http.HttpRequest;
import org.springframework.http.client.ClientHttpRequestExecution;

public class ExceptionUtil {
    public static SentinelClientHttpResponse handleBlock(
            HttpRequest request,
            byte[] body,
            ClientHttpRequestExecution execution,
            BlockException ex
    ){
        System.out.println("handleblock ex class: " + ex.getClass().getCanonicalName());
        return new SentinelClientHttpResponse("my block info");
    }

    public static SentinelClientHttpResponse handleFallback(
            HttpRequest request,
            byte[] body,
            ClientHttpRequestExecution execution,
            BlockException ex
    ){
        System.out.println("handle fallback ex class: " + ex.getClass().getCanonicalName());
        return new SentinelClientHttpResponse("my fallback info");
    }
}

在@SentinelRestTemplate 注解中添加异常处理的配置 fallbackClass降级异常用什么类 fallback处理方法。blockHandlerClass限流异常的类， blockHandler处理方法

@SentinelRestTemplate(fallbackClass = ExceptionUtil.class, fallback = "handleFallback",
blockHandlerClass = ExceptionUtil.class, blockHandler = "handleException")

验证步骤

Sentinel Console 中对此 RestTemplate 调用添加限流，阈值设为 1

快速多次访问“/resttemplate_sentinel”，应看到自定义的限流信息

Sentinel Console 中对此 RestTemplate 调用添加 RT 类型的降级规则，RT 设为 1，时间窗口设为 1

快速多次访问“/resttemplate_sentinel”，应看到自定义的降级信息

Feign 整合 Sentinel

属性配置 Feign Sentinel 开关

feign:
 sentinel:
   enabled: true

创建 service-provider 与 service-consumer，整合 nacos、Sentinel、Feign

Sentinel Console 中针对此 Feign 调用添加限流，阈值设为 1

快速多刷几次接口 “/hellofeign”，应显示限流效果

定义异常处理类

package com.example.demo;

import feign.hystrix.FallbackFactory;
import org.springframework.stereotype.Component;

@Component
public class FeignClientServiceFallbackFactory implements FallbackFactory<FeignClientService> {

    @Override
    public FeignClientService create(Throwable throwable) {
        return new FeignClientService() {
            @Override
            public String hello(String name) {
                System.out.println(throwable);
                return "my exception info";
            }
        };
    }
}

@FeignClient 注解中添加异常处理的配置

package com.example.demo;

import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;

@FeignClient(name = "service-provider", fallbackFactory = FeignClientServiceFallbackFactory.class)
public interface FeignClientService {
    @GetMapping("/hello")
    public String hello(@RequestParam("name") String name);
}

10.错误信息自定义与区分来源

之前我们添加限流规则时，有一项“针对来源”一直都是使用的默认“default”，就是不区分来源。假设一个场景，service A 的API“/query”的主要调用者是 service B，如果不区分来源，肯定会对 Service C 不公平。需要对 Service B 特殊关照，这就可以使用“针对来源”。

之前我们被限流或者降级后，看到的提示信息都是：

Blocked by Sentinel (flow limiting)

效果演示时没问题，但实际环境下这种信息会让我们比较困扰，到底是被限流了，还是被降级了呢？如果能针

对不同的情况给出不同的信息就好了，这个需求比较好实现。

如何判别来源

Sentinel 提供了“RequestOriginParser ”，我们只需要实现其中的“parseOrigin”方法，提供获取来源的方法即可，例如

package com.example.demo;

import com.alibaba.csp.sentinel.adapter.servlet.callback.RequestOriginParser;
import org.springframework.stereotype.Component;

import javax.servlet.http.HttpServletRequest;

@Component
public class MyRequestOriginParser implements RequestOriginParser {
    @Override
    public String parseOrigin(HttpServletRequest httpServletRequest) {
        //根据业务自定义
        return httpServletRequest.getParameter("from");
    }
}

Sentinel Console 中为“/hellofeign”设置限流，针对来源设置为“chrome”，阈值设为 1

访问接口 “/hellofeign?name=a&from=chrome”，应显示限流效果

授权规则

“针对来源”还有一个用处：用于实现授权规则。“流控应用”项与“针对来源”是一样的，“白名单”表示允许访问，“黑名单”表示不允许访问。例如：“流控应用”设为“service-user”，“授权类型”选择“黑名单”，表示“service-user”这个应用不允许访问此资源。

访问接口 “/hellofeign?name=a&from=“service-user” 成功，其他失败。

根据错误类型自定义错误信息

Sentinel 已经定义了不同类型的异常，包括 FlowException、DegradeException、ParamFlowException、SystemBlockException、AuthorityException。我们只需要定义一个异常处理类，针对不同的异常做不同的处理即可，例如：

package com.example.demo;

import com.alibaba.csp.sentinel.adapter.servlet.callback.UrlBlockHandler;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import com.alibaba.csp.sentinel.slots.block.authority.AuthorityException;
import com.alibaba.csp.sentinel.slots.block.degrade.DegradeException;
import com.alibaba.csp.sentinel.slots.block.flow.FlowException;
import com.alibaba.csp.sentinel.slots.block.flow.param.ParamFlowException;
import com.alibaba.csp.sentinel.slots.system.SystemBlockException;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.stereotype.Component;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@Component
public class MyUrlBlockHandler implements UrlBlockHandler {
    @Override
    public void blocked(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, BlockException e) throws IOException {
        // 1. 根据不同的异常类型，定义不同的错误信息
        String errmsg = "";
        if(e instanceof FlowException){
            errmsg = "限流";
        }else if(e instanceof DegradeException){
            errmsg = "降级";
        }else if(e instanceof ParamFlowException){
            errmsg = "热点参数";
        }else if(e instanceof SystemBlockException){
            errmsg = "系统规则";
        }else if(e instanceof AuthorityException){
            errmsg = "授权规则";
        }

        // 2. 输出错误信息
        httpServletResponse.setStatus(500);
        httpServletResponse.setCharacterEncoding("utf-8");
        httpServletResponse.setContentType("application/json;charset=utf-8");
        new ObjectMapper().writeValue(
                httpServletResponse.getWriter(), errmsg
        );
    }
}

11.规则持久化

之前我们实践 Sentinel 时，每次我们重启应用 Sentinel 控制台中的规则就都没有了，需要重新设置，这是为什么？因为应用的 Sentinel 规则是保存在内存中的。生产环境中，我们需要做好规则持久化。Sentinel 为我们提供了丰富的数据源工具包，便于集成各类数据源，我们需要自己开发代码进行对接。

生成环境建议推模式

改造流程

从sentinel 源码中找到sentinel-dashboard并引入

新建service-sentinel-nacos 模块 pom.xml

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.5.RELEASE</version>
        <relativePath/> 
    </parent>
    <groupId>com.example</groupId>
    <artifactId>service-sentinel-nacos</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>
    <name>service-sentinel-nacos</name>
    <description>Demo project for Spring Cloud alibaba</description>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <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>

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

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

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>
    
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Greenwich.SR5</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>2.1.1.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

改配置

server:
  port: 8081
spring:
  application:
    name: service-sentinel-nacos
  cloud:
    sentinel:
      transport:
        dashboard: localhost:8080
      datasource:
        flow:
          nacos:
            serverAddr: localhost:8848
            dataId: ${spring.application.name}-flow-rules
            groupId: SENTINEL_GROUP
            ruleType: FLOW
            dataType: json
management:
  endpoints:
    web:
      exposure:
        include: '*'

nacos 新建配置

改造sentinel 控制台

添加依赖

        <!-- for Nacos rule publisher sample -->
        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-datasource-nacos</artifactId>
<!--            <scope>test</scope>-->
        </dependency>

全pom.xml如下

<?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">
    <modelVersion>4.0.0</modelVersion>

    <parent>
        <groupId>com.alibaba.csp</groupId>
        <artifactId>sentinel-parent</artifactId>
        <version>1.7.0</version>
    </parent>

    <artifactId>sentinel-dashboard</artifactId>
    <packaging>jar</packaging>

    <properties>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <spring.boot.version>2.0.5.RELEASE</spring.boot.version>
        <curator.version>4.0.1</curator.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-core</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-web-servlet</artifactId>
            <version>${project.version}</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-transport-simple-http</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-parameter-flow-control</artifactId>
            <version>${project.version}</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-api-gateway-adapter-common</artifactId>
            <version>${project.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <version>${spring.boot.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-logging</artifactId>
            <version>${spring.boot.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <version>${spring.boot.version}</version>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.14</version>
        </dependency>

        <dependency>
            <groupId>commons-lang</groupId>
            <artifactId>commons-lang</artifactId>
            <version>2.6</version>
        </dependency>

        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>4.5.3</version>
        </dependency>
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpcore</artifactId>
            <version>4.4.5</version>
        </dependency>
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpasyncclient</artifactId>
            <version>4.1.3</version>
        </dependency>
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpcore-nio</artifactId>
            <version>4.4.6</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
        </dependency>

        <!-- for Nacos rule publisher sample -->
        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-datasource-nacos</artifactId>
<!--            <scope>test</scope>-->
        </dependency>
        <!-- for Apollo rule publisher sample -->
        <dependency>
            <groupId>com.ctrip.framework.apollo</groupId>
            <artifactId>apollo-openapi</artifactId>
            <version>1.2.0</version>
            <scope>test</scope>
        </dependency>

        <!--for Zookeeper rule publisher sample-->
        <dependency>
            <groupId>org.apache.curator</groupId>
            <artifactId>curator-recipes</artifactId>
            <version>${curator.version}</version>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.mockito</groupId>
            <artifactId>mockito-core</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>com.github.stefanbirkner</groupId>
            <artifactId>system-rules</artifactId>
            <version>1.16.1</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <finalName>sentinel-dashboard</finalName>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>${spring.boot.version}</version>
                <configuration>
                    <fork>true</fork>
                    <mainClass>com.alibaba.csp.sentinel.dashboard.DashboardApplication</mainClass>
                </configuration>
                <executions>
                    <execution>
                        <goals>
                            <goal>repackage</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>${maven.compiler.source}</source>
                    <target>${maven.compiler.target}</target>
                </configuration>
            </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-deploy-plugin</artifactId>
                <version>${maven.deploy.version}</version>
                <configuration>
                    <skip>true</skip>
                </configuration>
            </plugin>
        </plugins>

        <resources>
            <resource>
                <directory>src/main/resources</directory>
                <filtering>true</filtering>
            </resource>

            <resource>
                <directory>src/main/webapp/</directory>
                <excludes>
                    <exclude>resources/node_modules/**</exclude>
                </excludes>
            </resource>
        </resources>
    </build>
</project>

将test包下 com.alibaba.csp.sentinel.dashboard.rule 文件夹复制到 main 下。

修改 FlowControllerV2

    @Autowired
    @Qualifier("flowRuleNacosProvider")
    private DynamicRuleProvider<List<FlowRuleEntity>> ruleProvider;

    @Autowired
    @Qualifier("flowRuleNacosPublisher")
    private DynamicRulePublisher<List<FlowRuleEntity>> rulePublisher;

修改前端源码

webapp => resources => app => scripts => directives => sidebar => sidebar.html

打开注释

       <li ui-sref-active="active" ng-if="entry.appType==0">
            <a ui-sref="dashboard.flow({app: entry.app})">
              <i class="glyphicon glyphicon-filter"></i>&nbsp;&nbsp;流控规则 v1</a>
          </li>

全html 如下

<div class="navbar-default sidebar" role="navigation" style="overflow-y: auto;">
  <div class="sidebar-nav navbar-collapse">
    <ul class="nav in" id="side-menu">
      <li class="sidebar-search">
        <div class="input-group" style="">
          <input type="text" class="form-control highlight-border" placeholder="应用名" ng-model="searchApp">
          <span class="input-group-btn">
            <button class="btn btn-secondary btn-default-inverse" type="button">搜索</button>
          </span>
        </div>
      </li>
      <li ui-sref-active="active">
        <a ui-sref="dashboard.home" style="font-size:16px;">
          <span class="glyphicon glyphicon-dashboard"></span>
          &nbsp;&nbsp;首页</a>
      </li>

      <li ng-class="{active: true}" ng-repeat="entry in apps | filter: { app: searchApp }">{{dropDown}}
        <a href="javascript:void(0);" ng-click="click($event)" collapse="{{collpaseall == 1}}" style="font-size: 16px;word-break: break-word;">
          &nbsp;{{entry.app}}
          <span class="fa arrow"></span>
          <span class="arrow">({{entry.healthyCount}}/{{entry.machines.length}})</span>
        </a>

        <!--<ul class="nav nav-second-level" collapse="{{entry.active}}" style="display: none;">-->
        <ul class="nav nav-second-level" ng-show="entry.active">
          <li ui-sref-active="active">
            <a ui-sref="dashboard.metric({app: entry.app})">
              <i class="fa fa-bar-chart"></i>&nbsp;&nbsp;实时监控</a>
          </li>

          <li ui-sref-active="active" ng-if="!entry.isGateway">
            <a ui-sref="dashboard.identity({app: entry.app})">
              <i class="glyphicon glyphicon-list-alt"></i>&nbsp;&nbsp;簇点链路</a>
          </li>

          <li ui-sref-active="active" ng-if="entry.isGateway">
            <a ui-sref="dashboard.gatewayIdentity({app: entry.app})">
              <i class="glyphicon glyphicon-filter"></i>&nbsp;&nbsp;请求链路</a>
          </li>

          <li ui-sref-active="active" ng-if="entry.appType==0">
            <a ui-sref="dashboard.flow({app: entry.app})">
              <i class="glyphicon glyphicon-filter"></i>&nbsp;&nbsp;流控规则 Nacos</a>
          </li>

          <li ui-sref-active="active" ng-if="entry.isGateway">
            <a ui-sref="dashboard.gatewayApi({app: entry.app})">
              <i class="glyphicon glyphicon-tags"></i>&nbsp;&nbsp;&nbsp;API 管理</a>
          </li>
          <li ui-sref-active="active" ng-if="entry.isGateway">
            <a ui-sref="dashboard.gatewayFlow({app: entry.app})">
              <i class="glyphicon glyphicon-filter"></i>&nbsp;&nbsp;流控规则</a>
          </li>

          <li ui-sref-active="active" ng-if="!entry.isGateway">
            <a ui-sref="dashboard.flowV1({app: entry.app})">
              <i class="glyphicon glyphicon-filter"></i>&nbsp;&nbsp;流控规则 Memory</a>
          </li>

          <li ui-sref-active="active">
            <a ui-sref="dashboard.degrade({app: entry.app})">
              <i class="glyphicon glyphicon-flash"></i>&nbsp;&nbsp;降级规则</a>
          </li>
          <li ui-sref-active="active" ng-if="!entry.isGateway">
            <a ui-sref="dashboard.paramFlow({app: entry.app})">
              <i class="glyphicon glyphicon-fire"></i>&nbsp;&nbsp;热点规则</a>
          </li>
          <li ui-sref-active="active">
            <a ui-sref="dashboard.system({app: entry.app})">
              <i class="glyphicon glyphicon-lock"></i>&nbsp;&nbsp;系统规则</a>
          </li>
          <li ui-sref-active="active" ng-if="!entry.isGateway">
            <a ui-sref="dashboard.authority({app: entry.app})">
              <i class="glyphicon glyphicon-check"></i>&nbsp;&nbsp;授权规则</a>
          </li>
          <li ui-sref-active="active" ng-if="!entry.isGateway">
            <a ui-sref="dashboard.clusterAppServerList({app: entry.app})">
              <i class="glyphicon glyphicon-cloud"></i>&nbsp;&nbsp;集群流控</a>
          </li>

          <li ui-sref-active="active">
            <a ui-sref="dashboard.machine({app: entry.app})">
              <i class="glyphicon glyphicon-th-list"></i>&nbsp;&nbsp;机器列表</a>
          </li>
        </ul>
        <!-- /.nav-second-level -->
      </li>
    </ul>
  </div>
</div>

修改 js webapp => resources => app => scripts => controllers=> identity.js

FlowServiceV1 改成 FlowServiceV2

rule 添加降级规则

DegradeRuleNacosProvider.java

/*
 * Copyright 1999-2018 Alibaba Group Holding Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.alibaba.csp.sentinel.dashboard.rule.nacos;

import com.alibaba.csp.sentinel.dashboard.datasource.entity.rule.DegradeRuleEntity;
import com.alibaba.csp.sentinel.dashboard.datasource.entity.rule.FlowRuleEntity;
import com.alibaba.csp.sentinel.dashboard.datasource.entity.rule.RuleEntity;
import com.alibaba.csp.sentinel.dashboard.rule.DynamicRuleProvider;
import com.alibaba.csp.sentinel.datasource.Converter;
import com.alibaba.csp.sentinel.util.StringUtil;
import com.alibaba.nacos.api.config.ConfigService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import java.util.ArrayList;
import java.util.List;

/**
 * @author Eric Zhao
 * @since 1.4.0
 */
@Component("degradeRuleNacosProvider")
public class DegradeRuleNacosProvider implements DynamicRuleProvider<List<DegradeRuleEntity>> {

    @Autowired
    private ConfigService configService;
    @Autowired
    private Converter<String, List<DegradeRuleEntity>> converter;

    @Override
    public List<DegradeRuleEntity> getRules(String appName) throws Exception {
        String rules = configService.getConfig(appName + NacosConfigUtil.DEGRADE_DATA_ID_POSTFIX,
            NacosConfigUtil.GROUP_ID, 3000);
        if (StringUtil.isEmpty(rules)) {
            return new ArrayList<>();
        }
        return converter.convert(rules);
    }
}

DegradeRuleNacosPublisher.java

/*
 * Copyright 1999-2018 Alibaba Group Holding Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.alibaba.csp.sentinel.dashboard.rule.nacos;

import com.alibaba.csp.sentinel.dashboard.datasource.entity.rule.DegradeRuleEntity;
import com.alibaba.csp.sentinel.dashboard.datasource.entity.rule.FlowRuleEntity;
import com.alibaba.csp.sentinel.dashboard.rule.DynamicRulePublisher;
import com.alibaba.csp.sentinel.datasource.Converter;
import com.alibaba.csp.sentinel.util.AssertUtil;
import com.alibaba.nacos.api.config.ConfigService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import java.util.List;

/**
 * @author Eric Zhao
 * @since 1.4.0
 */
@Component("degradeRuleNacosPublisher")
public class DegradeRuleNacosPublisher implements DynamicRulePublisher<List<DegradeRuleEntity>> {

    @Autowired
    private ConfigService configService;
    @Autowired
    private Converter<List<DegradeRuleEntity>, String> converter;

    @Override
    public void publish(String app, List<DegradeRuleEntity> rules) throws Exception {
        AssertUtil.notEmpty(app, "app name cannot be empty");
        if (rules == null) {
            return;
        }
        configService.publishConfig(app + NacosConfigUtil.DEGRADE_DATA_ID_POSTFIX,
            NacosConfigUtil.GROUP_ID, converter.convert(rules));
    }
}

FlowRuleNacosProvider.java

/*
 * Copyright 1999-2018 Alibaba Group Holding Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.alibaba.csp.sentinel.dashboard.rule.nacos;

import com.alibaba.csp.sentinel.dashboard.datasource.entity.rule.FlowRuleEntity;
import com.alibaba.csp.sentinel.dashboard.rule.DynamicRuleProvider;
import com.alibaba.csp.sentinel.datasource.Converter;
import com.alibaba.csp.sentinel.util.StringUtil;
import com.alibaba.nacos.api.config.ConfigService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import java.util.ArrayList;
import java.util.List;

/**
 * @author Eric Zhao
 * @since 1.4.0
 */
@Component("flowRuleNacosProvider")
public class FlowRuleNacosProvider implements DynamicRuleProvider<List<FlowRuleEntity>> {

    @Autowired
    private ConfigService configService;
    @Autowired
    private Converter<String, List<FlowRuleEntity>> converter;

    @Override
    public List<FlowRuleEntity> getRules(String appName) throws Exception {
        String rules = configService.getConfig(appName + NacosConfigUtil.FLOW_DATA_ID_POSTFIX,
            NacosConfigUtil.GROUP_ID, 3000);
        if (StringUtil.isEmpty(rules)) {
            return new ArrayList<>();
        }
        return converter.convert(rules);
    }
}

FlowRuleNacosPublisher.java

/*
 * Copyright 1999-2018 Alibaba Group Holding Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.alibaba.csp.sentinel.dashboard.rule.nacos;

import com.alibaba.csp.sentinel.dashboard.datasource.entity.rule.FlowRuleEntity;
import com.alibaba.csp.sentinel.dashboard.rule.DynamicRulePublisher;
import com.alibaba.csp.sentinel.datasource.Converter;
import com.alibaba.csp.sentinel.util.AssertUtil;
import com.alibaba.nacos.api.config.ConfigService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import java.util.List;

/**
 * @author Eric Zhao
 * @since 1.4.0
 */
@Component("flowRuleNacosPublisher")
public class FlowRuleNacosPublisher implements DynamicRulePublisher<List<FlowRuleEntity>> {

    @Autowired
    private ConfigService configService;
    @Autowired
    private Converter<List<FlowRuleEntity>, String> converter;

    @Override
    public void publish(String app, List<FlowRuleEntity> rules) throws Exception {
        AssertUtil.notEmpty(app, "app name cannot be empty");
        if (rules == null) {
            return;
        }
        configService.publishConfig(app + NacosConfigUtil.FLOW_DATA_ID_POSTFIX,
            NacosConfigUtil.GROUP_ID, converter.convert(rules));
    }
}

NacosConfig.java

/*
 * Copyright 1999-2018 Alibaba Group Holding Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.alibaba.csp.sentinel.dashboard.rule.nacos;

import com.alibaba.csp.sentinel.dashboard.datasource.entity.rule.DegradeRuleEntity;
import com.alibaba.csp.sentinel.dashboard.datasource.entity.rule.FlowRuleEntity;
import com.alibaba.csp.sentinel.dashboard.datasource.entity.rule.RuleEntity;
import com.alibaba.csp.sentinel.datasource.Converter;
import com.alibaba.fastjson.JSON;
import com.alibaba.nacos.api.config.ConfigFactory;
import com.alibaba.nacos.api.config.ConfigService;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.util.List;

/**
 * @author Eric Zhao
 * @since 1.4.0
 */
@Configuration
public class NacosConfig {

    @Bean
    public Converter<List<FlowRuleEntity>, String> flowRuleEntityEncoder() {
        return JSON::toJSONString;
    }

    @Bean
    public Converter<String, List<FlowRuleEntity>> flowRuleEntityDecoder() {
        return s -> JSON.parseArray(s, FlowRuleEntity.class);
    }
    @Bean
    public Converter<List<DegradeRuleEntity>, String> degradeRuleEntityEncoder() {
        return JSON::toJSONString;
    }

    @Bean
    public Converter<String, List<DegradeRuleEntity>> degradeRuleEntityDecoder() {
        return s -> JSON.parseArray(s, DegradeRuleEntity.class);
    }

    @Bean
    public ConfigService nacosConfigService() throws Exception {
        return ConfigFactory.createConfigService("localhost");
    }
}

NacosConfigUtil.java

/*
 * Copyright 1999-2018 Alibaba Group Holding Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.alibaba.csp.sentinel.dashboard.rule.nacos;

/**
 * @author Eric Zhao
 * @since 1.4.0
 */
public final class NacosConfigUtil {

    public static final String GROUP_ID = "SENTINEL_GROUP";
    
    public static final String FLOW_DATA_ID_POSTFIX = "-flow-rules";
    public static final String DEGRADE_DATA_ID_POSTFIX = "-degrade-rules";
    public static final String PARAM_FLOW_DATA_ID_POSTFIX = "-param-rules";
    public static final String CLUSTER_MAP_DATA_ID_POSTFIX = "-cluster-map";

    /**
     * cc for `cluster-client`
     */
    public static final String CLIENT_CONFIG_DATA_ID_POSTFIX = "-cc-config";
    /**
     * cs for `cluster-server`
     */
    public static final String SERVER_TRANSPORT_CONFIG_DATA_ID_POSTFIX = "-cs-transport-config";
    public static final String SERVER_FLOW_CONFIG_DATA_ID_POSTFIX = "-cs-flow-config";
    public static final String SERVER_NAMESPACE_SET_DATA_ID_POSTFIX = "-cs-namespace-set";

    private NacosConfigUtil() {}
}

DegradeController 添加注入

    @Autowired
    @Qualifier("degradeRuleNacosPublisher")
    private DegradeRuleNacosPublisher degradeRuleNacosPublisher;

    @Autowired
    @Qualifier("degradeRuleNacosProvider")
    private DegradeRuleNacosProvider degradeRuleNacosProvider;

DegradeController 修改接口如下全文

/*
 * Copyright 1999-2018 Alibaba Group Holding Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.alibaba.csp.sentinel.dashboard.controller;

import java.util.Date;
import java.util.List;

import javax.servlet.http.HttpServletRequest;

import com.alibaba.csp.sentinel.dashboard.client.SentinelApiClient;
import com.alibaba.csp.sentinel.dashboard.discovery.MachineInfo;
import com.alibaba.csp.sentinel.dashboard.auth.AuthService;
import com.alibaba.csp.sentinel.dashboard.auth.AuthService.AuthUser;
import com.alibaba.csp.sentinel.dashboard.auth.AuthService.PrivilegeType;
import com.alibaba.csp.sentinel.dashboard.rule.nacos.DegradeRuleNacosProvider;
import com.alibaba.csp.sentinel.dashboard.rule.nacos.DegradeRuleNacosPublisher;
import com.alibaba.csp.sentinel.slots.block.RuleConstant;
import com.alibaba.csp.sentinel.util.StringUtil;

import com.alibaba.csp.sentinel.dashboard.datasource.entity.rule.DegradeRuleEntity;
import com.alibaba.csp.sentinel.dashboard.domain.Result;
import com.alibaba.csp.sentinel.dashboard.repository.rule.InMemDegradeRuleStore;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.http.MediaType;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

/**
 * @author leyou
 */
@Controller
@RequestMapping(value = "/degrade", produces = MediaType.APPLICATION_JSON_VALUE)
public class DegradeController {

    private final Logger logger = LoggerFactory.getLogger(DegradeController.class);

    @Autowired
    private InMemDegradeRuleStore repository;
    @Autowired
    private SentinelApiClient sentinelApiClient;

    @Autowired
    private AuthService<HttpServletRequest> authService;

    @Autowired
    @Qualifier("degradeRuleNacosPublisher")
    private DegradeRuleNacosPublisher degradeRuleNacosPublisher;

    @Autowired
    @Qualifier("degradeRuleNacosProvider")
    private DegradeRuleNacosProvider degradeRuleNacosProvider;

    @ResponseBody
    @RequestMapping("/rules.json")
    public Result<List<DegradeRuleEntity>> queryMachineRules(HttpServletRequest request, String app, String ip, Integer port) {
        AuthUser authUser = authService.getAuthUser(request);
        authUser.authTarget(app, PrivilegeType.READ_RULE);

        if (StringUtil.isEmpty(app)) {
            return Result.ofFail(-1, "app can't be null or empty");
        }
        if (StringUtil.isEmpty(ip)) {
            return Result.ofFail(-1, "ip can't be null or empty");
        }
        if (port == null) {
            return Result.ofFail(-1, "port can't be null");
        }
        try {
            List<DegradeRuleEntity> rules = degradeRuleNacosProvider.getRules(app);
            rules = repository.saveAll(rules);
            return Result.ofSuccess(rules);
        } catch (Throwable throwable) {
            logger.error("queryApps error:", throwable);
            return Result.ofThrowable(-1, throwable);
        }
    }

    @ResponseBody
    @RequestMapping("/new.json")
    public Result<DegradeRuleEntity> add(HttpServletRequest request,
                                         String app, String ip, Integer port, String limitApp, String resource,
                                         Double count, Integer timeWindow, Integer grade) {
        AuthUser authUser = authService.getAuthUser(request);
        authUser.authTarget(app, PrivilegeType.WRITE_RULE);

        if (StringUtil.isBlank(app)) {
            return Result.ofFail(-1, "app can't be null or empty");
        }
        if (StringUtil.isBlank(ip)) {
            return Result.ofFail(-1, "ip can't be null or empty");
        }
        if (port == null) {
            return Result.ofFail(-1, "port can't be null");
        }
        if (StringUtil.isBlank(limitApp)) {
            return Result.ofFail(-1, "limitApp can't be null or empty");
        }
        if (StringUtil.isBlank(resource)) {
            return Result.ofFail(-1, "resource can't be null or empty");
        }
        if (count == null) {
            return Result.ofFail(-1, "count can't be null");
        }
        if (timeWindow == null) {
            return Result.ofFail(-1, "timeWindow can't be null");
        }
        if (grade == null) {
            return Result.ofFail(-1, "grade can't be null");
        }
        if (grade < RuleConstant.DEGRADE_GRADE_RT || grade > RuleConstant.DEGRADE_GRADE_EXCEPTION_COUNT) {
            return Result.ofFail(-1, "Invalid grade: " + grade);
        }
        DegradeRuleEntity entity = new DegradeRuleEntity();
        entity.setApp(app.trim());
        entity.setIp(ip.trim());
        entity.setPort(port);
        entity.setLimitApp(limitApp.trim());
        entity.setResource(resource.trim());
        entity.setCount(count);
        entity.setTimeWindow(timeWindow);
        entity.setGrade(grade);
        Date date = new Date();
        entity.setGmtCreate(date);
        entity.setGmtModified(date);
        try {
            entity = repository.save(entity);
            publishRules(entity.getApp());
        } catch (Throwable throwable) {
            logger.error("add error:", throwable);
            return Result.ofThrowable(-1, throwable);
        }

        return Result.ofSuccess(entity);
    }

    @ResponseBody
    @RequestMapping("/save.json")
    public Result<DegradeRuleEntity> updateIfNotNull(HttpServletRequest request,
                                                     Long id, String app, String limitApp, String resource,
                                                     Double count, Integer timeWindow, Integer grade) {
        AuthUser authUser = authService.getAuthUser(request);
        if (id == null) {
            return Result.ofFail(-1, "id can't be null");
        }
        if (grade != null) {
            if (grade < RuleConstant.DEGRADE_GRADE_RT || grade > RuleConstant.DEGRADE_GRADE_EXCEPTION_COUNT) {
                return Result.ofFail(-1, "Invalid grade: " + grade);
            }
        }
        DegradeRuleEntity entity = repository.findById(id);
        if (entity == null) {
            return Result.ofFail(-1, "id " + id + " dose not exist");
        }
        authUser.authTarget(entity.getApp(), PrivilegeType.WRITE_RULE);
        if (StringUtil.isNotBlank(app)) {
            entity.setApp(app.trim());
        }

        if (StringUtil.isNotBlank(limitApp)) {
            entity.setLimitApp(limitApp.trim());
        }
        if (StringUtil.isNotBlank(resource)) {
            entity.setResource(resource.trim());
        }
        if (count != null) {
            entity.setCount(count);
        }
        if (timeWindow != null) {
            entity.setTimeWindow(timeWindow);
        }
        if (grade != null) {
            entity.setGrade(grade);
        }
        Date date = new Date();
        entity.setGmtModified(date);
        try {
            entity = repository.save(entity);
            publishRules(entity.getApp());
        } catch (Throwable throwable) {
            logger.error("save error:", throwable);
            return Result.ofThrowable(-1, throwable);
        }
        return Result.ofSuccess(entity);
    }

    @ResponseBody
    @RequestMapping("/delete.json")
    public Result<Long> delete(HttpServletRequest request, Long id) {
        AuthUser authUser = authService.getAuthUser(request);
        if (id == null) {
            return Result.ofFail(-1, "id can't be null");
        }

        DegradeRuleEntity oldEntity = repository.findById(id);
        if (oldEntity == null) {
            return Result.ofSuccess(null);
        }
        authUser.authTarget(oldEntity.getApp(), PrivilegeType.DELETE_RULE);
        try {
            repository.delete(id);
            publishRules(oldEntity.getApp());
        } catch (Throwable throwable) {
            logger.error("delete error:", throwable);
            return Result.ofThrowable(-1, throwable);
        }

        return Result.ofSuccess(id);
    }

    private void publishRules(String app) throws Exception{
        List<DegradeRuleEntity> degradeRuleEntities = repository.findAllByApp(app);
        degradeRuleNacosPublisher.publish(app, degradeRuleEntities);
    }
}

service-sentinel-nacos 修改配置文件添加降级配置

server:
  port: 8081
spring:
  application:
    name: service-sentinel-nacos
  cloud:
    sentinel:
      transport:
        dashboard: localhost:8080
      datasource:
        flow:
          nacos:
            serverAddr: localhost:8848
            dataId: ${spring.application.name}-flow-rules
            groupId: SENTINEL_GROUP
            ruleType: FLOW
            dataType: json
        degrade:
          nacos:
            serverAddr: localhost:8848
            dataId: ${spring.application.name}-degrade-rules
            groupId: SENTINEL_GROUP
            ruleType: DEGRADE
            dataType: json
management:
  endpoints:
    web:
      exposure:
        include: '*'

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原文地址：https://www.cnblogs.com/lilb/p/14418696.html