sentinel 之 客户端

简介

基于spring boot 和 sentinel注解实现

maven依赖

    <properties>
        <sentinel.version>1.6.0</sentinel.version>
        <java.version>1.8</java.version>
    </properties>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>2.1.3.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>

            <dependency>
                <artifactId>sentinel-extension</artifactId>
                <groupId>com.alibaba.csp</groupId>
                <version>${sentinel.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-transport-simple-http</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-core</artifactId>
        </dependency>

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

        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-annotation-aspectj</artifactId>
        </dependency>

注解支持

package com.zm.demo.sentinel.client.controller.config;

import com.alibaba.csp.sentinel.annotation.aspectj.SentinelResourceAspect;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class SentinelAspectConfiguration {

    @Bean
    public SentinelResourceAspect sentinelResourceAspect() {
        return new SentinelResourceAspect();
    }
}

规则初始化

package com.zm.demo.sentinel.client.controller.config;

import com.alibaba.csp.sentinel.datasource.FileRefreshableDataSource;
import com.alibaba.csp.sentinel.datasource.FileWritableDataSource;
import com.alibaba.csp.sentinel.datasource.ReadableDataSource;
import com.alibaba.csp.sentinel.datasource.WritableDataSource;
import com.alibaba.csp.sentinel.init.InitFunc;
import com.alibaba.csp.sentinel.slots.block.degrade.DegradeRule;
import com.alibaba.csp.sentinel.slots.block.degrade.DegradeRuleManager;
import com.alibaba.csp.sentinel.transport.util.WritableDataSourceRegistry;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.TypeReference;
import org.springframework.stereotype.Component;

import javax.annotation.PostConstruct;
import java.util.List;

@Component
public class FileDataSourceInit implements InitFunc {

    @PostConstruct
    @Override
    public void init() throws Exception {
        String degradeRulePath = "E:\\git\\sentinelconfig.txt";

        ReadableDataSource<String, List<DegradeRule>> ds = new FileRefreshableDataSource<>(
                degradeRulePath, source -> JSON.parseObject(source, new TypeReference<List<DegradeRule>>() {})
        );
        // 将可读数据源注册至 DegradeRuleManager.
        DegradeRuleManager.register2Property(ds.getProperty());

        WritableDataSource<List<DegradeRule>> wds = new FileWritableDataSource<>(degradeRulePath, this::encodeJson);
        // 将可写数据源注册至 transport 模块的 WritableDataSourceRegistry 中.
        // 这样收到控制台推送的规则时，Sentinel 会先更新到内存，然后将规则写入到文件中.
        WritableDataSourceRegistry.registerDegradeDataSource(wds);
    }

    private <T> String encodeJson(T t) {
        return JSON.toJSONString(t);
    }
}

资源及fallback

package com.zm.demo.sentinel.client.controller;

import com.alibaba.csp.sentinel.annotation.SentinelResource;
import com.alibaba.fastjson.JSONObject;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * @author zoum
 * @create 2019/5/7 11:24
 */
@RestController
public class UserController {

    @SentinelResource(value = "getUserInfo", fallback="getUserInfoFallback", fallbackClass = {UserControllerFallback.class})
    @RequestMapping
    public JSONObject getUserInfo(Integer id) throws InterruptedException{
        JSONObject jsonObject = new JSONObject();
        jsonObject.put("id", id);
        jsonObject.put("name", "zm");
        jsonObject.put("age", "20");
        Thread.sleep(1001L);
        return jsonObject;
    }
}

package com.zm.demo.sentinel.client.controller;

import com.alibaba.fastjson.JSONObject;

/**
 * @author zoum
 * @create 2019/5/7 11:29
 */
public class UserControllerFallback {


    public static JSONObject getUserInfoFallback(Integer id) throws InterruptedException{
        JSONObject jsonObject = new JSONObject();
        jsonObject.put("id", id);
        jsonObject.put("name", "zmmm");
        jsonObject.put("age", "188");
        return jsonObject;
    }
}

启动类

package com.zm.demo.sentinel.client;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

/**
 * 启动时增加启动参数：
 * -Dcsp.sentinel.dashboard.server=localhost:8080 控制台ip及端口
 * -Dproject.name=sentinel-client 客户端名称
 * @author zoum
 * @create 2019/5/7 11:23
 */
@SpringBootApplication
public class App {

    public static void main(String[] args){
        SpringApplication.run(App.class, args);
    }
}

配置

application.yml

server:
  port: 8081

验证

请求：http://localhost:8081/?id=1

熔断降级

描述：满足一次熔断条件，之后连续4次，一共五次都满足条件，则进行熔断降级。

熔断降级配置

[{"count":10.0,"grade":0,"limitApp":"default","passCount":0,"resource":"getUserInfo","timeWindow":20}]

count: 响应时间(ms)
limitApp：限制APP
passCount：通过量
resource： 资源名称
timeWindow：窗口时间，即当次熔断降级多久之后不再熔断

循环50次结果：

可以看出有45次请求被降级拒绝掉，返回fallback结果。
第6次开始熔断，如下：

移除测试代码：Thread.sleep(1001L);
循环请求请求50次：

image.png

可以看出，50次全部正常通过。

流控

控制台配置流控规则，qps限制为10

循环请求10次，不会触发控制规则，如下图：

image.png

并发请求20次，触发流控规则，如下图：