04.Spring Cloud Alibaba学习笔记–Sentinel简介及安装配置

Sentinel是什么

Sentinel 与 Hystrix 的比较

Hystrix

需要手工搭建监控平台
没有可以进行更加细粒度化配置的 Web 界面，比如流控、速率控制、服务熔断、服务降级等

Sentinel

单独一个组件，可以独立出来，搭建难度降低
提供了可以进行细粒度统一配置的 Web 界面

Sentinel下载安装运行

下载

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

找到 sentinel-dashboard-1.7.0.jar 进行下载

运行

确保 Java 8 运行环境正常，确保 8080 端口没有被占用。

运行命令：

java -jar sentinel-dashboard-1.7.0.jar

访问 Sentinel 管理界面

http://localhost:8080

默认用户名 / 密码为 sentinel / sentinel

Sentinel 初始化监控

启动

Nacos
Sentinel

创建工程

1、建 Module

cloudalibaba-sentinel-server8401

2、改 POM

<?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">
    <parent>
        <artifactId>cloud2020</artifactId>
        <groupId>demo.yangxu.springcloud</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>cloudalibaba-sentinel-server8401</artifactId>

    <dependencies>
        <dependency><!-- 引入自己定义的api通用包，可以使用Payment支付Entity -->
            <groupId>demo.yangxu.springcloud</groupId>
            <artifactId>cloud-api-commons</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
        <!--SpringCloud ailibaba nacos -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <!--SpringCloud ailibaba sentinel-datasource-nacos 后续做持久化用到-->
        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-datasource-nacos</artifactId>
        </dependency>
        <!--SpringCloud ailibaba sentinel -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
        </dependency>
        <!--openfeign-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>
        <!-- SpringBoot整合Web组件+actuator -->
        <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>
        <!--日常通用jar包配置-->
        <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>

</project>

3、写 YML

application.yaml

server:
  port: 8401

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

4、主启动类

SentinelMain8401

package demo.yangxu.springcloud.alibaba;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

@SpringBootApplication
@EnableDiscoveryClient
public class SentinelMain8401 {
    public static void main(String[] args) {
        SpringApplication.run(SentinelMain8401.class, args);
    }
}

5、业务类

FlowLimitController

package demo.yangxu.springcloud.alibaba.controller;

import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@Slf4j
public class FlowLimitController {

    @GetMapping("/testA")
    public String testA()
    {
        return "------testA";
    }

    @GetMapping("/testB")
    public String testB()
    {
        log.info(Thread.currentThread().getName()+"\t"+"...testB");
        return "------testB";
    }
}

启动8401微服务后查看Sentinel控制台

由于 Sentinel 采用的是懒加载，需要至少访问一次 Controller 中的相关网址，才能在 Sentinel 的控制台中看到信息。

访问：

http://localhost:8401/testA

http://localhost:8401/testB

访问完成后再次访问 Sentinel 控制台

http://localhost:8080/#/dashboard

04.Spring Cloud Alibaba学习笔记

Sentinel简介及安装配置