090_Hystrix 断路器

目录

• 简介
  • 分布式系统面临的问题
  • 服务雪崩
  • 什么是Hystrix
  • Hystrix能干嘛
• 服务熔断是什么
• Hystrix 服务熔断实现
  • 创建服务提供者Hystrix子模块
  • pom.xml
  • mybatis
  • application.yml
  • 业务类
  • @HystrixCommand
  • 启动类
  • 启动测试
• Hystrix 服务降级实现
  • 实体类子模块springcloud-api
    • 添加调用服务提供者失败时调用的工厂类
    • Feign接口添加服务失败时，调用的工厂类注解
  • 服务消费者Feign子模块springcloud-consumer-dept-feign-80
    • application.yml开启服务降级
  • 启动测试
• 服务熔断与服务降级对比
• Hystrix Dashboard流监控
  • 创建Dashboard子模块
  • pom.xml
  • application.yml
  • 启动类
  • 启动测试
  • 服务提供者子模块springcloud-provider-dept-8001
    • pom.xml添加actuator监控依赖和Hystrix依赖
    • 启动类注册Bean
  • 启动测试
  • 监控页面说明
    • 7色
    • 一圈
    • 一线
    • 整图说明

简介

分布式系统面临的问题

服务雪崩

什么是Hystrix

Hystrix：https://github.com/Netflix/hystrix

Hystrix能干嘛

服务熔断是什么

Hystrix 服务熔断实现

创建服务提供者Hystrix子模块

pom.xml

<?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>springcloud</artifactId>
        <groupId>com.qing</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>springcloud-provider-dept-hystrix-8001</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>

    <dependencies>
        <!--springcloud-api模块，实体类-->
        <dependency>
            <groupId>com.qing</groupId>
            <artifactId>springcloud-api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
        </dependency>
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-core</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-test</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--jetty-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jetty</artifactId>
        </dependency>
        <!--热部署-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
        </dependency>
        <!--服务提供者使用eureka，eureka服务端使用eureka-server-->
        <!-- https://mvnrepository.com/artifact/org.springframework.cloud/spring-cloud-starter-eureka -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
            <version>1.4.6.RELEASE</version>
        </dependency>
        <!--完善Eureka监控信息 actuator-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-hystrix</artifactId>
            <version>1.4.6.RELEASE</version>
        </dependency>

    </dependencies>

</project>

mybatis

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <settings>
        <!--开启二级缓存-->
        <setting name="cacheEnabled" value="true"/>
    </settings>
</configuration>

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.qing.springcloud.mapper.DeptMapper">
    <insert id="add" parameterType="com.qing.springcloud.pojo.Dept">
        insert into dept (dname, db_source)
            values (#{dname}, database())
    </insert>

    <select id="queryById" parameterType="Long" resultType="com.qing.springcloud.pojo.Dept">
        select * from dept where deptno = #{id}
    </select>

    <select id="queryAll" resultType="com.qing.springcloud.pojo.Dept">
        select * from dept
    </select>
</mapper>

application.yml

server:
  port: 8001

mybatis:
  type-aliases-package: com.qing.springcloud.pojo
  config-location: classpath:mybatis/mybatis-config.xml
  mapper-locations: classpath:mybatis/mapper/*.xml
# 开启驼峰
#  configuration:
#    map-underscore-to-camel-case: true

spring:
  application:
    name: springcloud-provider-dept
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: org.gjt.mm.mysql.Driver
    url: jdbc:mysql://localhost:3306/db01?useUnicode=true&characterEncoding=utf-8&useSSL=false
    username: root
    password: 123456

# Eureka
eureka:
  client:
    service-url:
      # 单机：defaultZone: http://localhost:7001/eureka/ # 使用Eureka服务端配置的注册url
      # 集群：
      defaultZone: http://eureka7001.com:7001/eureka/,http://eureka7002.com:7002/eureka/,http://eureka7003.com:7003/eureka/ # 使用Eureka服务端配置的注册url
#  instance:
#    instance-id: springcloud-provider-dept-zdy # 修改Eureka监控页面上服务默认描述
# 监控信息 actuator-info配置
info:
  app.name: qing-springcloud
  company.name: 清风阁

业务类

package com.qing.springcloud.mapper;

import com.qing.springcloud.pojo.Dept;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;

import java.util.List;

@Mapper
@Repository
public interface DeptMapper {

    public boolean add(Dept dept);

    public Dept queryById(Long id);

    public List<Dept> queryAll();
}

package com.qing.springcloud.service;

import com.qing.springcloud.pojo.Dept;

import java.util.List;

public interface DeptService {

    public boolean add(Dept dept);

    public Dept queryById(Long id);

    public List<Dept> queryAll();
}

package com.qing.springcloud.service.impl;

import com.qing.springcloud.mapper.DeptMapper;
import com.qing.springcloud.pojo.Dept;
import com.qing.springcloud.service.DeptService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class DeptServiceImpl implements DeptService {

    @Autowired
    private DeptMapper deptMapper;

    @Override
    public boolean add(Dept dept) {
        return deptMapper.add(dept);
    }

    @Override
    public Dept queryById(Long id) {
        return deptMapper.queryById(id);
    }

    @Override
    public List<Dept> queryAll() {
        return deptMapper.queryAll();
    }
}

@HystrixCommand

package com.qing.springcloud.controller;

import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand;
import com.qing.springcloud.pojo.Dept;
import com.qing.springcloud.service.DeptService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

/**
 * 提供服务
 */
@RestController
public class DeptController {

    @Autowired
    private DeptService deptService;

    @GetMapping("/dept/get/{id}")
    @HystrixCommand(fallbackMethod = "hystrixGet") // 服务失败时调用的方法
    public Dept get(@PathVariable("id") Long id) {
        Dept dept = deptService.queryById(id);
        if (dept == null) {
            throw new RuntimeException();
        }
        return dept;
    }

    // 服务失败时调用的方法
    public Dept hystrixGet(@PathVariable("id") Long id) {
        return new Dept()
                .setDeptno(id)
                .setDname("id=>" + id + "没有对应的信息")
                .setDb_source("no this database in MySQL");
    }
}

启动类

package com.qing.springcloud;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.circuitbreaker.EnableCircuitBreaker;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;

@EnableCircuitBreaker // 开启对熔断的支持
@EnableDiscoveryClient // 开启服务发现
@EnableEurekaClient // 在服务启动后自动注册到Eureka中
@SpringBootApplication
public class DeptProviderHystrix_8001 {
    public static void main(String[] args) {
        SpringApplication.run(DeptProviderHystrix_8001.class, args);
    }
}

启动测试

启动Eureka服务端，启动服务提供者Hystrix

Hystrix 服务降级实现

实体类子模块springcloud-api

添加调用服务提供者失败时调用的工厂类

package com.qing.springcloud.service;

import com.qing.springcloud.pojo.Dept;
import feign.hystrix.FallbackFactory;
import org.springframework.stereotype.Component;

import java.util.List;

// 服务降级
@Component
public class DeptClientServiceFallbackFactory implements FallbackFactory {
    @Override
    public DeptClientService create(Throwable throwable) {
        return new DeptClientService() {
            @Override
            public boolean add(Dept dept) {
                return false;
            }

            @Override
            public Dept get(Long id) {
                return new Dept()
                        .setDeptno(id)
                        .setDname("id=>" + id + "没有对应的信息，客户端提供了降级的信息，这个服务现在已经被关闭")
                        .setDb_source("没有数据");
            }

            @Override
            public List<Dept> listAll() {
                return null;
            }
        };
    }
}

Feign接口添加服务失败时，调用的工厂类注解

@FeignClient(value = "springcloud-provider-dept", fallbackFactory = DeptClientServiceFallbackFactory.class) // value值为服务提供者的服务名称

package com.qing.springcloud.service;

import com.qing.springcloud.pojo.Dept;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;

import java.util.List;

@FeignClient(value = "springcloud-provider-dept", fallbackFactory = DeptClientServiceFallbackFactory.class) // value值为服务提供者的服务名称
@Component
public interface DeptClientService {

    @PostMapping("/dept/add")
    public boolean add(Dept dept);

    @GetMapping("/dept/get/{id}")
    public Dept get(Long id);

    @GetMapping("/dept/listAll")
    public List<Dept> listAll();
}

服务消费者Feign子模块springcloud-consumer-dept-feign-80

application.yml开启服务降级

server:
  port: 80

# 开启服务降级
feign:
  hystrix:
    enabled: true

# Eureka
eureka:
  client:
    register-with-eureka: false # 不向eureka注册自己
    service-url:
      defaultZone: http://eureka7001.com:7001/eureka/,http://eureka7002.com:7002/eureka/,http://eureka7003.com:7003/eureka/

启动测试

启动Eureka服务端，服务提供者，服务消费者Feign

服务提供者关闭时：

服务熔断与服务降级对比

Hystrix Dashboard流监控

创建Dashboard子模块

pom.xml

<?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>springcloud</artifactId>
        <groupId>com.qing</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>springcloud-consumer-hystrix-dashboard</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>

    <dependencies>
        <!--springcloud-api模块，实体类-->
        <dependency>
            <groupId>com.qing</groupId>
            <artifactId>springcloud-api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--热部署-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
        </dependency>
        <!--服务提供者和服务消费者使用eureka，eureka服务端使用eureka-server-->
        <!-- https://mvnrepository.com/artifact/org.springframework.cloud/spring-cloud-starter-eureka -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
            <version>1.4.6.RELEASE</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework.cloud/spring-cloud-starter-ribbon -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-ribbon</artifactId>
            <version>1.4.6.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-feign</artifactId>
            <version>1.4.6.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-hystrix</artifactId>
            <version>1.4.6.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-hystrix-dashboard</artifactId>
            <version>1.4.6.RELEASE</version>
        </dependency>

    </dependencies>

</project>

application.yml

server:
  port: 9001

启动类

package com.qing.springcloud;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.hystrix.dashboard.EnableHystrixDashboard;

@EnableHystrixDashboard // 开启Dashboard监控
@SpringBootApplication
public class DeptConsumerDashboard_9001 {
    public static void main(String[] args) {
        SpringApplication.run(DeptConsumerDashboard_9001.class, args);
    }
}

启动测试

启动监控模块

访问地址：http://localhost:9001/hystrix

服务提供者子模块springcloud-provider-dept-8001

pom.xml添加actuator监控依赖和Hystrix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>springcloud</artifactId>
        <groupId>com.qing</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>springcloud-provider-dept-8001</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>

    <dependencies>
        <!--springcloud-api模块，实体类-->
        <dependency>
            <groupId>com.qing</groupId>
            <artifactId>springcloud-api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
        </dependency>
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-core</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-test</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--jetty-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jetty</artifactId>
        </dependency>
        <!--热部署-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
        </dependency>
        <!--服务提供者使用eureka，eureka服务端使用eureka-server-->
        <!-- https://mvnrepository.com/artifact/org.springframework.cloud/spring-cloud-starter-eureka -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
            <version>1.4.6.RELEASE</version>
        </dependency>
        <!--完善Eureka监控信息 actuator-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-hystrix</artifactId>
            <version>1.4.6.RELEASE</version>
        </dependency>

    </dependencies>

</project>

启动类注册Bean

package com.qing.springcloud;

import com.netflix.hystrix.contrib.metrics.eventstream.HystrixMetricsStreamServlet;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.context.annotation.Bean;

/**
 * 启动类
 */
@EnableDiscoveryClient // 开启服务发现
@EnableEurekaClient // 在服务启动后自动注册到Eureka中
@SpringBootApplication
public class DeptProvider_8001 {
    public static void main(String[] args) {
        SpringApplication.run(DeptProvider_8001.class, args);
    }

    @Bean
    public ServletRegistrationBean hystrixMetricsStreamServlet() {
        ServletRegistrationBean registrationBean = new ServletRegistrationBean(new HystrixMetricsStreamServlet());
        registrationBean.addUrlMappings("/actuator/hystrix.stream");
        return registrationBean;
    }
}

启动测试

:::tips
启动Eureka服务端和服务提供者
先测试流是否正常
:::

再测试服务是否可以调用

测试监控
访问地址：http://localhost:9001/hystrix
流地址：http://localhost:8001/actuator/hystrix.stream

监控页面说明

7色

一圈

一线

整图说明