[Java知识库]spring-cloud-alibaba-sentinel服务熔断限流

测试之前必须搭建好nacos并且启动

pom依赖

<?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>2.5.3</version>
    </parent>
    <groupId>com.baojiaren</groupId>
    <artifactId>sentinel</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>sentinel</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>2020.0.3</spring-cloud.version>
        <spring-cloud-alibaba.version>2.2.1.RELEASE</spring-cloud-alibaba.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>

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

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
            <version>2021.1</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.alibaba.csp/sentinel-spring-webmvc-adapter -->
        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-spring-webmvc-adapter</artifactId>
            <version>1.8.2</version>
        </dependency>
    </dependencies>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>${spring-cloud-alibaba.version}</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>

yml

spring:
  application:
    name: nacos-sentinel
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848
        enabled: true
server:
  port: 8080

第一种方法:手动配置管理Api限流接口

MemberService

package com.baojiaren.service;


import com.alibaba.csp.sentinel.Entry;
import com.alibaba.csp.sentinel.SphU;
import com.alibaba.csp.sentinel.slots.block.RuleConstant;
import com.alibaba.csp.sentinel.slots.block.flow.FlowRule;
import com.alibaba.csp.sentinel.slots.block.flow.FlowRuleManager;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

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

/**
 * @author ?????.倾心?、
 * @create 2021-08-01-19:45
 */
@RestController
public class MemberService {
    private static final String GETUSER_KEY = "getUser";


    /**
     * 初始化路由策略
     *
     * @return
     */
    @RequestMapping("/initFlowQpsRule")
    public String initFlowQpsRule() {
        List<FlowRule> rules = new ArrayList<FlowRule>();
        FlowRule rule1 = new FlowRule();
        rule1.setResource(GETUSER_KEY);
        // QPS控制在1以内
        rule1.setCount(1);
        // QPS限流
        rule1.setGrade(RuleConstant.FLOW_GRADE_QPS);
        rule1.setLimitApp("default");
        rules.add(rule1);
        FlowRuleManager.loadRules(rules);
        return "初始化配置策略成功..";
    }


    @RequestMapping("/getUser")
    public String getUser() {
        Entry entry = null;
        try {
            entry = SphU.entry(GETUSER_KEY);
        } catch (Exception e) {
            return "当前频率访问次数过多，请稍后重试!";
        } finally {
            if (entry != null) {
                entry.exit();
            }
        }
        return "baojiaren:8080";
    }
    
}

首先访问http://localhost:8080/initFlowQpsRule 进行初始化配置

配置成功了1秒之内疯狂刷新访问就会发生限流表示成功
http://localhost:8080/getUser

手动放入到项目启动自动加载
当SpringBoot项目启动成功之后，加载限流规则。

package com.baojiaren;

import com.alibaba.csp.sentinel.slots.block.RuleConstant;
import com.alibaba.csp.sentinel.slots.block.flow.FlowRule;
import com.alibaba.csp.sentinel.slots.block.flow.FlowRuleManager;
import org.springframework.boot.ApplicationArguments;
import org.springframework.boot.ApplicationRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

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

@SpringBootApplication
public class SentinelApplication  implements ApplicationRunner {
    private static final String GETORDER_GEIUSER_KEY = "getUser";
    public static void main(String[] args) {
        SpringApplication.run(SentinelApplication.class, args);
    }

    @Override
    public void run(ApplicationArguments args) throws Exception {
        List<FlowRule> rules = new ArrayList<FlowRule>();
        FlowRule rule1 = new FlowRule();
        rule1.setResource(GETORDER_GEIUSER_KEY);
        // QPS控制在1以内
        rule1.setCount(1);
        // QPS限流
        rule1.setGrade(RuleConstant.FLOW_GRADE_QPS);
        rule1.setLimitApp("default");
        rules.add(rule1);
        FlowRuleManager.loadRules(rules);
        System.out.println("<启动加载FlowRule配置成功...>");
    }
}

第二种方法:注解

package com.baojiaren.service;

import com.alibaba.csp.sentinel.adapter.spring.webmvc.callback.BlockExceptionHandler;
import com.alibaba.csp.sentinel.annotation.SentinelResource;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * @author ?????.倾心?、
 * @create 2021-08-07-10:48
 */
@RestController
public class OrderService {

    private static final String GETUSER_KEY = "orderToMember";
    /**注解内方法
     * fallback()  服务降级执行本地方法
     * blockHandler() 限流/熔断出现异常执行的方法
     * value() 指定我们资源的名称
     * @return
     */
    @SentinelResource(value = GETUSER_KEY,blockHandler = "getOrderQpsException")
    @RequestMapping("/getOrder")
    public String  orderToMemberSentinelResource(){

        return "orderSentinelResource";
    }


    /**
     * 被限流后返回的提示
     * @param e
     * @return
     */
    public String getOrderQpsException(BlockException e){
        e.printStackTrace();

        return "该接口已经被限流了";
    }
}

package com.baojiaren;

import com.alibaba.csp.sentinel.slots.block.RuleConstant;
import com.alibaba.csp.sentinel.slots.block.flow.FlowRule;
import com.alibaba.csp.sentinel.slots.block.flow.FlowRuleManager;
import org.springframework.boot.ApplicationArguments;
import org.springframework.boot.ApplicationRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

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

@SpringBootApplication
public class SentinelApplication  implements ApplicationRunner {
    private static final String GETORDER_GEIUSER_KEY = "getUser";
    public static void main(String[] args) {
        SpringApplication.run(SentinelApplication.class, args);
    }

    @Override
    public void run(ApplicationArguments args) throws Exception {
        List<FlowRule> rules = new ArrayList<FlowRule>();
        FlowRule rule1 = new FlowRule();
        FlowRule rule2 = new FlowRule();
        rule1.setResource(GETORDER_GEIUSER_KEY);
        rule2.setResource("orderToMember");
        // QPS控制在1以内
        rule1.setCount(1);
        rule2.setCount(1);
        // QPS限流
        rule1.setGrade(RuleConstant.FLOW_GRADE_QPS);
        rule1.setLimitApp("default");
        rules.add(rule1);
        rule2.setGrade(RuleConstant.FLOW_GRADE_QPS);
        rule2.setLimitApp("default");
        rules.add(rule1);
        rules.add(rule2);
        FlowRuleManager.loadRules(rules);
        System.out.println("<启动加载FlowRule配置成功...>");
    }
}

第三种:控制台

添加依赖

  		<dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-core</artifactId>
            <version>1.8.2</version>
        </dependency>

yml

spring:
  application:
    name: nacos-sentinel
  cloud:
    nacos:
      discovery:
        server-addr: nacos.baojiarenteshan.com

        enabled: true

    sentinel:
      transport:
        dashboard: 127.0.0.1:8718  #开启sentinel控制台
      eager: true
server:
  port: 8080

第三种控制台

如果启动遇到java.lang.NoClassDefFoundError: com/alibaba/csp/sentinel/spi/SpiLoader
之类的问题 都是版本不兼容导致的问题 下面出的依赖是本人尝试可以使用的版本
版本不兼容也是一个巨坑
中文文档:https://github.com/alibaba/Sentinel/wiki/%E4%BB%8B%E7%BB%8D
控制台下载地址:https://github.com/alibaba/Sentinel/releases/tag/1.8.0
注意版本不要选最新真的很坑

运行命令
其中 -Dserver.port=8080 用于指定 Sentinel 控制台端口为 8080
-Dcsp.sentinel.dashboard.server为访问地址
-Dproject.name为项目名称
从 Sentinel 1.6.0 起，Sentinel 控制台引入基本的登录功能，默认用户名和密码都是 sentinel 可以参考 鉴权模块文档 配置用户名和密码
控制台中文文档:https://github.com/alibaba/Sentinel/wiki/%E6%8E%A7%E5%88%B6%E5%8F%B0

java -Dserver.port=8080 -Dcsp.sentinel.dashboard.server=localhost:8080  -jar  sentinel-dashboard-1.8.0.jar

项目启动之前需要在启动类配置启动参数
第一个参数为已经启动的控制台地址,第二个为这个项目的名称

-Dcsp.sentinel.dashboard.server=localhost:8080 -Dproject.name=sentinel

pom依赖

<?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>2.4.2</version>
    </parent>
    <groupId>com.baojiaren</groupId>
    <artifactId>sentinel</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>sentinel</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>2020.0.3</spring-cloud.version>
        <spring-cloud-alibaba.version>2.2.5.RELEASE</spring-cloud-alibaba.version>
        <spring-cloud-sentinel>1.8.0</spring-cloud-sentinel>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>commons-io</groupId>
            <artifactId>commons-io</artifactId>
            <version>2.11.0</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-spring-webmvc-adapter</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-transport-simple-http</artifactId>
            <version>1.8.0</version>
        </dependency>
    </dependencies>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>${spring-cloud-alibaba.version}</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>
        <resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.xml</include>
                </includes>
            </resource>
        </resources>
    </build>
</project>

package com.baojiaren.service;

import com.alibaba.csp.sentinel.adapter.spring.webmvc.callback.BlockExceptionHandler;
import com.alibaba.csp.sentinel.annotation.SentinelResource;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * @author ?????.倾心?、
 * @create 2021-08-07-10:48
 */
@RestController
public class OrderService {

    private static final String GETUSER_KEY = "orderToMember";
    /**注解内方法
     * fallback()  服务降级执行本地方法
     * blockHandler() 限流/熔断出现异常执行的方法
     * value() 指定我们资源的名称
     * @return
     */
    @SentinelResource(value = GETUSER_KEY,blockHandler = "getOrderQpsException")
    @RequestMapping("/getOrder")
    public String  orderToMemberSentinelResource(){

        return "orderSentinelResource";
    }


    /**
     * 被限流后返回的提示
     * @param e
     * @return
     */
    public String getOrderQpsException(BlockException e){
        e.printStackTrace();

        return "该接口已经被限流了";
    }

    /**
     * 基于控制台创建规则实现限流 value = "getOrderConsole" getOrderConsole为控制台填写的资源名称
     * @return
     */
    @SentinelResource(value = "getOrderConsole",blockHandler = "getOrderQpsException")
    @RequestMapping("/getOrderConsole")
    public String getOrderConsole(){

        return "getOrderConsole";
    }
}

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