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SpringCloud Hystrix熔断器如何使用

2023-07-05 14:07:13 411人浏览八月长安

摘要

本文小编为大家详细介绍“SpringCloud Hystrix熔断器如何使用”，内容详细，步骤清晰，细节处理妥当，希望这篇“springCloud Hystrix熔断器如何使用”文章能帮助大家解决疑惑，下面跟着小编的思路

本文小编为大家详细介绍“SpringCloud Hystrix熔断器如何使用”，内容详细，步骤清晰，细节处理妥当，希望这篇“springCloud Hystrix熔断器如何使用”文章能帮助大家解决疑惑，下面跟着小编的思路慢慢深入，一起来学习新知识吧。

Hystrix(hi si ju ke si)概述

Hystix 是 Netflix 开源的一个延迟和容错库，用于隔离访问远程服务、第三方库，防止出现级联失败（雪崩）。

雪崩：一个服务失败，导致整条链路的服务都失败的情形。

Hystix 主要功能

隔离
降级
熔断
限流

隔离

线程池隔离
信号量隔离

Hystrix 降级

Hystix 降级：当服务发生异常或调用超时，返回默认数据

SpringCloud Hystrix熔断器如何使用

Hystrix降级-服务提供方

在服务提供方，引入 hystrix 依赖
定义降级方法
使用 @HystrixCommand 注解配置降级方法
在启动类上开启Hystrix功能：@EnableCircuitBreaker

初始化程序和Fiegn程序一致

需要修改的程序

package com.itheima.provider;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.cloud.client.circuitbreaker.EnableCircuitBreaker;import org.springframework.cloud.netflix.eureka.EnableEurekaClient;@EnableEurekaClient //该注解 在新版本中可以省略@SpringBootApplication@EnableCircuitBreaker ///开启Hystrix功能public class ProviderApp {    public static void main(String[] args) {        SpringApplication.run(ProviderApp.class,args);    }}

测试的程序

package com.itheima.provider.controller;import com.itheima.provider.domain.Goods;import com.itheima.provider.service.GoodsService;import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand;import com.netflix.hystrix.contrib.javanica.annotation.HystrixProperty;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.beans.factory.annotation.Value;import org.springframework.WEB.bind.annotation.GetMapping;import org.springframework.web.bind.annotation.PathVariable;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RestController;import java.util.Date;@RestController@RequestMapping("/goods")public class GoodsController {    @Autowired    private GoodsService goodsService;    @Value("${server.port}")    private int port;        @GetMapping("/findOne/{id}")    @HystrixCommand(fallbackMethod = "findOne_fallback",commandProperties = {            //设置Hystrix的超时时间 默认1s            @HystrixProperty(name="execution.isolation.thread.timeoutInMilliseconds",value = "3000")    })///指定降级后的方法    public Goods findOne(@PathVariable("id") int id)  {        ///1 造个异常        //int i =3/0;        try {            Thread.sleep(2000);//sleep interrupted        } catch (InterruptedException e) {            e.printStackTrace();        }        Goods goods = goodsService.findOne(id);        goods.setTitle(goods.getTitle() + ":" + port);//将端口号，设置到了 商品标题上        return goods;    }        public Goods findOne_fallback(int id) {        Goods goods = new Goods();        goods.setTitle("降级了~~~");        return goods;    }}

指定坐标

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

Hystrix降级-服务消费方

feign 组件已经集成了 hystrix 组件。
定义feign 调用接口实现类，复写方法，即降级方法
在 @FeignClient 注解中使用 fallback 属性设置降级处理类。
配置开启 feign.hystrix.enabled = true

provider与Fiegin一致

application.yml修改

server:
port: 9000
eureka:
instance:
hostname: localhost # 主机名
client:
service-url:
defaultZone: Http://localhost:8761/eureka
spring:
application:
name: hystrix-consumer # 设置当前应用的名称。将来会在eureka中Application显示。将来需要使用该名称来获取路径
#开启feign对hystrix支持
feign:
hystrix:
enabled: true

ConsumerApp修改

package com.itheima.consumer;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.cloud.client.discovery.EnableDiscoveryClient;import org.springframework.cloud.netflix.eureka.EnableEurekaClient;import org.springframework.cloud.openfeign.EnableFeignClients;@EnableDiscoveryClient // 激活DiscoveryClient@EnableEurekaClient@SpringBootApplication@EnableFeignClients //开启Feign的功能public class ConsumerApp {    public static void main(String[] args) {        SpringApplication.run(ConsumerApp.class,args);    }}

修改GoodsFeignClient方法

package com.itheima.consumer.feign;import com.itheima.consumer.domain.Goods;import org.springframework.cloud.openfeign.FeignClient;import org.springframework.web.bind.annotation.GetMapping;import org.springframework.web.bind.annotation.PathVariable;@FeignClient(value = "HYSTRIX-PROVIDER",fallback = GoodsFeignClientFallback.class)public interface GoodsFeignClient {    @GetMapping("/goods/findOne/{id}")    public Goods findGoodsById(@PathVariable("id") int id);}

复写方法

package com.itheima.consumer.feign;import com.itheima.consumer.domain.Goods;import org.springframework.stereotype.Component;@Componentpublic class GoodsFeignClientFallback implements  GoodsFeignClient{    @Override    public Goods findGoodsById(int id) {        Goods goods = new Goods();        goods.setTitle("又被降级了~~");        return goods;    }}

Hystrix 熔断

Hystrix 熔断机制，用于监控 微服务调用情况，当失败的情况达到预定的阈值（5秒失败20次），会打开断路器，拒绝所有请求，直到服务恢复正常为止。

circuitBreaker.sleepWindowInMilliseconds：监控时间
circuitBreaker.requestVolumeThreshold：失败次数
circuitBreaker.errorThresholdPercentage：失败率

SpringCloud Hystrix熔断器如何使用

//设置Hystrix的超时时间 默认1s@HystrixProperty(name="execution.isolation.thread.timeoutInMilliseconds",value = "3000"),//监控的时间 默认5000ms@HystrixProperty(name="circuitBreaker.sleepWindowInMilliseconds",value = "1000"),//失败次数，默认20次@HystrixProperty(name="circuitBreaker.requestVolumeThreshold",value = "2"),//失败率 百分之50@HystrixProperty(name="circuitBreaker.errorThresholdPercentage",value = "100")

Hystrix 熔断监控

Hystrix 提供了 Hystrix-dashboard 功能，用于实时监控微服务运行状态。
但是Hystrix-dashboard只能监控一个微服务。
Netflix 还提供了 Turbine ，进行聚合监控。

SpringCloud Hystrix熔断器如何使用

Turbine聚合监控

搭建监控模块

创建监控模块

创建hystrix-monitor模块，使用Turbine聚合监控多个Hystrix dashboard功能,

引入Turbine聚合监控起步依赖

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">    <parent>        <artifactId>hystrix-parent</artifactId>        <groupId>com.itheima</groupId>        <version>1.0-SNAPSHOT</version>    </parent>    <modelVersion>4.0.0</modelVersion>    <artifactId>hystrix-monitor</artifactId>    <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>    <!--单独熔断监控-->        <dependency>            <groupId>org.springframework.cloud</groupId>            <artifactId>spring-cloud-starter-netflix-hystrix-dashboard</artifactId>        </dependency><!--聚合熔断监控-->        <dependency>            <groupId>org.springframework.cloud</groupId>            <artifactId>spring-cloud-starter-netflix-turbine</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-netflix-eureka-client</artifactId>        </dependency>        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-test</artifactId>            <scope>test</scope>        </dependency>    </dependencies>    <build>        <plugins>            <plugin>                <groupId>org.springframework.boot</groupId>                <artifactId>spring-boot-maven-plugin</artifactId>            </plugin>        </plugins>    </build></project>

修改application.yml

spring:
application.name: hystrix-monitor
server:
port: 8769
turbine:
combine-host-port: true
# 配置需要监控的服务名称列表
app-config: hystrix-provider,hystrix-consumer
cluster-name-expression: "'default'"
aggregator:
cluster-config: default
#instanceUrlSuffix: /actuator/hystrix.stream
eureka:
client:
serviceUrl:
defaultZone: http://localhost:8761/eureka/

创建启动类

@SpringBootApplication@EnableEurekaClient@EnableTurbine //开启Turbine 很聚合监控功能@EnableHystrixDashboard //开启Hystrix仪表盘监控功能public class HystrixMonitorApp {    public static void main(String[] args) {        SpringApplication.run(HystrixMonitorApp.class, args);    }}

修改被监控模块

需要分别修改 hystrix-provider 和 hystrix-consumer 模块：

导入依赖：

<dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-actuator</artifactId>        </dependency>        <dependency>            <groupId>org.springframework.cloud</groupId>            <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>        </dependency>        <dependency>            <groupId>org.springframework.cloud</groupId>            <artifactId>spring-cloud-starter-netflix-hystrix-dashboard</artifactId>        </dependency>

配置Bean

此处为了方便，将其配置在启动类中。

@Bean    public ServletReGIStrationBean getServlet() {        HystrixMetriCSStreamServlet streamServlet = new HystrixMetricsStreamServlet();        ServletRegistrationBean registrationBean = new ServletRegistrationBean(streamServlet);        registrationBean.setLoadOnStartup(1);        registrationBean.addUrlMappings("/actuator/hystrix.stream");        registrationBean.setName("HystrixMetricsStreamServlet");        return registrationBean;    }

启动类上添加注解@EnableHystrixDashboard

@EnableDiscoveryClient@EnableEurekaClient@SpringBootApplication@EnableFeignClients @EnableHystrixDashboard // 开启Hystrix仪表盘监控功能public class ConsumerApp {    public static void main(String[] args) {        SpringApplication.run(ConsumerApp.class,args);    }    @Bean    public ServletRegistrationBean getServlet() {        HystrixMetricsStreamServlet streamServlet = new HystrixMetricsStreamServlet();        ServletRegistrationBean registrationBean = new ServletRegistrationBean(streamServlet);        registrationBean.setLoadOnStartup(1);        registrationBean.addUrlMappings("/actuator/hystrix.stream");        registrationBean.setName("HystrixMetricsStreamServlet");        return registrationBean;    }}