安装Sentinel控制台与初始化演示工程

分手后的思念是犯贱 2023-10-11 20:44 9阅读 0赞

**目录**

一、Sentinel

二、安装Sentinel控制台

（一）sentinel组件由2部分构成

（二）安装步骤

三、初始化演示工程

四、流控模式

（一）快速失败

（二）关联资源

（三）链路

（四）预热（Warm Up）

（五）排队等待

--------------------

## 一、Sentinel ##

官网：[GitHub - alibaba/Sentinel: A powerful flow control component enabling reliability, resilience and monitoring for microservices. (面向云原生微服务的高可用流控防护组件)][GitHub - alibaba_Sentinel_ A powerful flow control component enabling reliability_ resilience and monitoring for microservices.]

中文文档：[https://github.com/alibaba/Sentinel/wiki/%E4%BB%8B%E7%BB%8D][https_github.com_alibaba_Sentinel_wiki_E4_BB_8B_E7_BB_8D]

![7093c9f126e745999e12199838c49541.png][] 理解为Hystrix的加强版即可

下载地址：[https://github.com/alibaba/Sentinel/releases][https_github.com_alibaba_Sentinel_releases]

![9ce3795d2558429fbbb7447a9ea623ac.png][]

[Spring Cloud Alibaba Reference Documentation (spring-cloud-alibaba-group.github.io)][Spring Cloud Alibaba Reference Documentation _spring-cloud-alibaba-group.github.io]

> **解决服务使用中的各种问题：**
> 
> **服务雪崩、服务降级、服务熔断、服务限流**

## 二、安装Sentinel控制台 ##

### （一）sentinel组件由2部分构成 ###

![01e60b2717214e4caebb74c1e9c6d4e0.png][]

后台以及前台8080

### （二）安装步骤 ###

下载地址：[https://github.com/alibaba/Sentinel/releases][https_github.com_alibaba_Sentinel_releases]

下载到本地sentinel-dashboard-1.7.0.jar

**前提**：java8环境OK 8080端口不能被占用

以jar包方式运行

> **java -jar sentinel-dashboard-1.7.0.jar**

**访问sentinel管理界面**

登录账号密码均为sentinel

[http://localhost:8080][http_localhost_8080]

![0d11cc13fb754cc29cce148a1406c8ab.png][]

## 三、初始化演示工程 ##

nacos要先启动成功

新建module cloudalibaba-sentinel-service8401

POM

<dependencies>
            
            <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>
            
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
            </dependency>
            
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-openfeign</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>
            
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-devtools</artifactId>
                <scope>runtime</scope>
                <optional>true</optional>
            </dependency>
            <dependency>
                <groupId>cn.hutool</groupId>
                <artifactId>hutool-all</artifactId>
                <version>4.6.3</version>
            </dependency>
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <optional>true</optional>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
            </dependency>
    
        </dependencies>

YML

server:
      port: 8401
    
    spring:
      application:
        name: cloudalibaba-sentinel-service
      cloud:
        nacos:
          discovery:
            #Nacos服务注册中心地址
            server-addr: localhost:8848
        sentinel:
          transport:
            #配置Sentinel dashboard地址
            dashboard: localhost:8080
            #默认8719端口，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: '*'

主启动

@EnableDiscoveryClient
    @SpringBootApplication
    public class MainApp8401
    {
        public static void main(String[] args) {
            SpringApplication.run(MainApp8401.class, args);
        }
    }

业务类FlowLimitController

@RestController
    public class FlowLimitController
    {
    
        @GetMapping("/testA")
        public String testA()
        {
            return "------testA";
        }
    
        @GetMapping("/testB")
        public String testB()
        {
            return "------testB";
        }
    }

启动Sentinel8080后启动该微服务

因为Sentinel采用的是懒加载方式，所以我们需要先访问微服务的方法，Sentinel控制台才会出现监控

![a38365ea67fe478c8262024948911447.png][]

## 四、流控模式 ##

基本介绍

![d82aa6b2449e4e4891fd15351249c8a4.png][]

### （一）快速失败 ###

**快速失败（QPS）**

![a1a74bebf19144858ee34f1694e1174d.png][]

**快速失败（线程）**

这里使线程睡眠模仿业务

@GetMapping("/testA")
        public String testA()
        {
            try {
                TimeUnit.MILLISECONDS.sleep(1000);
            } catch (Exception e) {
                System.out.println(e);
            }
            return "------testA";
        }

开两个页面访问，当一个页面业务未解决完毕，别的线程被限流

![c3b12bc9c5c24f25ad57f813c54b3738.png][]

###  **（二）关联资源** ###

当关联的资源达到阈值时，就限流自己。比如，当与订单接口关联的资源支付接口达到阀值后，就限流订单接口自己

**设置效果**  
当关联资源/testB的qps阀值超过1时，就限流/testA的Rest访问地址，当关联资源到阈值后限制配置好的资源名

![70841d5bde8b4e5da7c50b20a052f5b3.png][]

使用postman模拟并发密集访问testB

先测试访问testB成功，这里要点击一下save保存请求内容

![a469c3a0290943eebb437c1b1e7806ea.png][]

postman里新建多线程集合组

![3efd4ffcf12d4532b273e938cc533a9e.png][]

将访问地址添加进新新线程组

![93caaa58ae2e4111977af909760f20eb.png][]

Run

![cd1c38dd54b54e02b54ffc0d437ce5ee.png][]

A被限流了

![e584a87b176a439b82f4b4b9422e2bc8.png][]

### （三）链路 ###

链路：**阈值统计时，只统计从指定资源进入当前资源的请求，是对请求来源的限流**

[sentinel流控规则\_机智的爆爆哥的博客-CSDN博客][sentinel_-CSDN]

[Sentinel 链路流控模式失效 · Issue \#1213 · alibaba/Sentinel (github.com)][Sentinel _ _ Issue _1213 _ alibaba_Sentinel _github.com]

### **（四）预热（Warm Up）** ###

官网：[流量控制 · alibaba/Sentinel Wiki (github.com)][_ alibaba_Sentinel Wiki _github.com]

![acece857ca2540cea7b3694b11f7a6da.png][]

解释：默认coldFactor为3，即请求 QPS 从 threshold / 3 开始，经预热时长逐渐升至设定的 QPS 阈值。

**案例**，阀值为10+预热时长设置5秒。  
系统初始化的阀值为10 / 3 约等于3,即阀值刚开始为3；然后过了5秒后阀值才慢慢升高恢复到10

![0c9c47d6936b45eb87d5e04fac93201c.png][]

**应用场景**

秒杀系统在开启的瞬间，会有很多流量上来，很有可能把系统打死，预热方式就是把为了保护系统，可慢慢的把流量放进来，慢慢的把阀值增长到设置的阀值。

### （五）排队等待 ###

**匀速排队，阈值必须设置为QPS**

官网

![6e92f24476f14778981a0234074db5ec.png][]

设置含义：/testA每秒1次请求，超过的话就排队等待，等待的超时时间为20000毫秒。

![d452e28dd73d4bc7b9896cb451899214.png][]

测试

![1cccaa70b5e04244a661041fcd9a23d3.png][]

[GitHub - alibaba_Sentinel_ A powerful flow control component enabling reliability_ resilience and monitoring for microservices.]: https://github.com/alibaba/Sentinel
[https_github.com_alibaba_Sentinel_wiki_E4_BB_8B_E7_BB_8D]: https://github.com/alibaba/Sentinel/wiki/%E4%BB%8B%E7%BB%8D
[7093c9f126e745999e12199838c49541.png]: https://img-blog.csdnimg.cn/7093c9f126e745999e12199838c49541.png
[https_github.com_alibaba_Sentinel_releases]: https://github.com/alibaba/Sentinel/releases
[9ce3795d2558429fbbb7447a9ea623ac.png]: https://img-blog.csdnimg.cn/9ce3795d2558429fbbb7447a9ea623ac.png
[Spring Cloud Alibaba Reference Documentation _spring-cloud-alibaba-group.github.io]: https://spring-cloud-alibaba-group.github.io/github-pages/greenwich/spring-cloud-alibaba.html#_spring_cloud_alibaba_sentinel
[01e60b2717214e4caebb74c1e9c6d4e0.png]: https://img-blog.csdnimg.cn/01e60b2717214e4caebb74c1e9c6d4e0.png
[http_localhost_8080]: http://localhost:8080
[0d11cc13fb754cc29cce148a1406c8ab.png]: https://img-blog.csdnimg.cn/0d11cc13fb754cc29cce148a1406c8ab.png
[a38365ea67fe478c8262024948911447.png]: https://img-blog.csdnimg.cn/a38365ea67fe478c8262024948911447.png
[d82aa6b2449e4e4891fd15351249c8a4.png]: https://img-blog.csdnimg.cn/d82aa6b2449e4e4891fd15351249c8a4.png
[a1a74bebf19144858ee34f1694e1174d.png]: https://img-blog.csdnimg.cn/a1a74bebf19144858ee34f1694e1174d.png
[c3b12bc9c5c24f25ad57f813c54b3738.png]: https://img-blog.csdnimg.cn/c3b12bc9c5c24f25ad57f813c54b3738.png
[70841d5bde8b4e5da7c50b20a052f5b3.png]: https://img-blog.csdnimg.cn/70841d5bde8b4e5da7c50b20a052f5b3.png
[a469c3a0290943eebb437c1b1e7806ea.png]: https://img-blog.csdnimg.cn/a469c3a0290943eebb437c1b1e7806ea.png
[3efd4ffcf12d4532b273e938cc533a9e.png]: https://img-blog.csdnimg.cn/3efd4ffcf12d4532b273e938cc533a9e.png
[93caaa58ae2e4111977af909760f20eb.png]: https://img-blog.csdnimg.cn/93caaa58ae2e4111977af909760f20eb.png
[cd1c38dd54b54e02b54ffc0d437ce5ee.png]: https://img-blog.csdnimg.cn/cd1c38dd54b54e02b54ffc0d437ce5ee.png
[e584a87b176a439b82f4b4b9422e2bc8.png]: https://img-blog.csdnimg.cn/e584a87b176a439b82f4b4b9422e2bc8.png
[sentinel_-CSDN]: https://blog.csdn.net/weixin_44353507/article/details/113815458
[Sentinel _ _ Issue _1213 _ alibaba_Sentinel _github.com]: https://github.com/alibaba/Sentinel/issues/1213
[_ alibaba_Sentinel Wiki _github.com]: https://github.com/alibaba/Sentinel/wiki/%E6%B5%81%E9%87%8F%E6%8E%A7%E5%88%B6
[acece857ca2540cea7b3694b11f7a6da.png]: https://img-blog.csdnimg.cn/acece857ca2540cea7b3694b11f7a6da.png
[0c9c47d6936b45eb87d5e04fac93201c.png]: https://img-blog.csdnimg.cn/0c9c47d6936b45eb87d5e04fac93201c.png
[6e92f24476f14778981a0234074db5ec.png]: https://img-blog.csdnimg.cn/6e92f24476f14778981a0234074db5ec.png
[d452e28dd73d4bc7b9896cb451899214.png]: https://img-blog.csdnimg.cn/d452e28dd73d4bc7b9896cb451899214.png
[1cccaa70b5e04244a661041fcd9a23d3.png]: https://img-blog.csdnimg.cn/1cccaa70b5e04244a661041fcd9a23d3.png