Spring Cloud学习笔记4-熔断器Hystrix + 监控Turbine

傷城~ 2022-04-04 11:16 238阅读 0赞

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title: “Spring Cloud学习笔记4-熔断器Hystrix + 监控Turbine”

url: “[https://wsk1103.github.io/][https_wsk1103.github.io]”

tags:

*  Spring Cloud
 *  学习笔记

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#### 备注： ####

**官网**：[http://spring.io/projects/spring-cloud][http_spring.io_projects_spring-cloud]

**总纲**：[https://cloud.spring.io/spring-cloud-static/Finchley.SR2/single/spring-cloud.html][https_cloud.spring.io_spring-cloud-static_Finchley.SR2_single_spring-cloud.html]

**JAVA**： 1.8 +

**MAVEN**： 3.5.0 +

**Spring Boot**：2.0.7.RELEASE

**Spring Cloud**：Finchley

说明：Netflix has created a library called Hystrix that implements the circuit breaker pattern. In a microservice architecture, it is common to have multiple layers of service calls, as shown in the following example:

Netflix创建了一个名为Hystrix的库，用于实现断路器模式。在微服务架构中，通常有多层服务调用，如以下示例所示：（熔断器监控界面）  
![image][]

## A service failure in the lower level of services can cause cascading failure all the way up to the user. When calls to a particular service exceed circuitBreaker.requestVolumeThreshold (default: 20 requests) and the failure percentage is greater than circuitBreaker.errorThresholdPercentage (default: >50%) in a rolling window defined by metrics.rollingStats.timeInMilliseconds (default: 10 seconds), the circuit opens and the call is not made. In cases of error and an open circuit, a fallback can be provided by the developer.   一句话，Hystrix的快速失败可以有效防止雪崩效应。   ![image][image 1] ##

本项目地址：[https://github.com/wsk1103/my-spring-cloud][https_github.com_wsk1103_my-spring-cloud]

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## Feign集成Hystrix ##

延用学习笔记3的项目，对其进行修改

#### 1. 修改pom.xml，增加 ####

<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>

#### 2. application.yml 增加新的配置 ####

# 因为feign默认集成了hystrix，但是是处于关闭状态。
    feign:
      hystrix:
        enabled: true

#### 3. 修改SericeFeignApplication ####

注解增加  
//启动hystrix  
@EnableHystrix  
@EnableCircuitBreaker

#### 4. 修改 包service -> HiService ####

在注解@FeignClient新增属性fallback，其中的值HiServiceHystricImpl.class为该接口的实现，在接口访问失败的时候，就会快速调用HiServiceHystricImpl.class里面对应的方法。

package com.wsk.feign.service;
    
    import com.wsk.feign.service.impl.HiServiceHystricImpl;
    import org.springframework.cloud.openfeign.FeignClient;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    import org.springframework.web.bind.annotation.RequestParam;
    
    /**
     * @author WuShukai
     * @version V1.0
     * @description
     * @date 2018/11/23  11:26
     */
    @FeignClient(value = "service-client",fallback = HiServiceHystricImpl.class)
    public interface HiService {
        @RequestMapping(value = "/hi",method = RequestMethod.GET)
        String say(@RequestParam(value = "name") String name);
    }

#### 5. 增加接口的的实现类 ####

package com.wsk.feign.service.impl;
    
    import com.wsk.feign.service.HiService;
    import org.springframework.stereotype.Component;
    
    /**
     * @author WuShukai
     * @version V1.0
     * @description 熔断器，快速失败
     * @date 2018/11/23  14:29
     */
    @Component
    public class HiServiceHystricImpl implements HiService {
    
        /**
         * 当访问失败的时候，会快速调用该方法直接返回。
         *
         * @param name
         * @return
         */
        @Override
        public String say(String name) {
            return "sorry,error:" + name;
        }
    }

#### 6. 修改SericeFeignApplication ####

新增注解  
//表明开启熔断器  
@EnableHystrix  
@EnableCircuitBreaker

package com.wsk.feign;
    
    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;
    import org.springframework.cloud.netflix.hystrix.EnableHystrix;
    import org.springframework.cloud.openfeign.EnableFeignClients;
    import org.springframework.web.bind.annotation.RestController;
    
    @SpringBootApplication
    @EnableEurekaClient
    @EnableDiscoveryClient
    @EnableFeignClients
    @RestController
    @EnableHystrix
    @EnableCircuitBreaker
    public class SericeFeignApplication {
    
        public static void main(String[] args) {
            SpringApplication.run(SericeFeignApplication.class, args);
        }
    
    }

## Feign整合Hystrix Dashboard监控数据聚合（Turbine） ##

Turbine是Netflix开源的将Server-Sent Event（SSE）的JSON数据流聚合成单个流的工具。我们可以通过Turbine将Hystrix生产的监控数据（JSON）合并到一个流中，方便我们对存在多个实例的应用进行监控。

#### 1. 为Feign项目修改application.yml ####

# 熔断器
    management:
      endpoints:
        web:
          exposure:
            include: "*"
          cors:
            allowed-origins: "*"
            allowed-methods: "*"

#### 2. 为Feign项目新增包configuration -> 新增类 HystrixConfiguration ####

package com.wsk.feign.configuration;
    
    import com.netflix.hystrix.contrib.metrics.eventstream.HystrixMetricsStreamServlet;
    import org.springframework.boot.web.servlet.ServletRegistrationBean;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    
    /**
     * @author WuShukai
     * @version V1.0
     * @description
     * @date 2018/12/10  10:19
     */
    @Configuration
    public class HystrixConfiguration {
    
        @Bean(name = "hystrixRegistrationBean")
        public ServletRegistrationBean servletRegistrationBean() {
            ServletRegistrationBean registration = new ServletRegistrationBean(
                    new HystrixMetricsStreamServlet(), "/hystrix.stream");
            registration.setName("hystrixServlet");
            registration.setLoadOnStartup(1);
            return registration;
        }
    
        @Bean(name = "hystrixForTurbineRegistrationBean")
        public ServletRegistrationBean servletTurbineRegistrationBean() {
            ServletRegistrationBean registration = new ServletRegistrationBean(
                    new HystrixMetricsStreamServlet(), "/actuator/hystrix.stream");
            registration.setName("hystrixForTurbineServlet");
            registration.setLoadOnStartup(1);
            return registration;
        }
    }

#### 3. 新建项目turbine ####

搭建方法同学习笔记1中新建module

#### 4. 修改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">
        <modelVersion>4.0.0</modelVersion>
    
        <groupId>com.wsk</groupId>
        <artifactId>turbine</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <packaging>jar</packaging>
    
        <name>turbine</name>
        <description>service-turbine</description>
    
        <parent>
            <groupId>my-spring-cloud</groupId>
            <artifactId>MySpringCloud</artifactId>
            <version>1.0-SNAPSHOT</version>
        </parent>
    
        <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>
            <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-dashboard</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-netflix-turbine</artifactId>
            </dependency>
        </dependencies>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
            </plugins>
        </build>
    
    
    </project>

#### 5. 重命名application.properties为application.yml ####

server:
      port: 8764
    
    spring:
      application:
        name: service-turbine
    
    eureka:
      client:
        serviceUrl:
          defaultZone: http://localhost:8761/eureka/
    
    turbine:
    #指定需要监控的servicename，多个service以,间隔
      app-config: service-feign
    #指定集群名称，默认为default，当设立了多个集群时，可以在Hystrix指定集群名称来查看监控
      clusterNameExpression: new String("default")
    #合并同一个host多个端口的数据
      combine-host-port: true

#### 6. 修改SericeFeignApplication ####

新增注解  
@EnableDiscoveryClient  
//开启界面报表  
@EnableHystrixDashboard  
//开启Turbine  
@EnableTurbine

package com.wsk.turbine;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
    import org.springframework.cloud.netflix.hystrix.dashboard.EnableHystrixDashboard;
    import org.springframework.cloud.netflix.turbine.EnableTurbine;
    
    @SpringBootApplication
    @EnableDiscoveryClient
    //开启界面报表
    @EnableHystrixDashboard
    //开启Turbine
    @EnableTurbine
    public class TurbineApplication {
    
        public static void main(String[] args) {
            SpringApplication.run(TurbineApplication.class, args);
        }
    }

## 输出 ##

#### 1. 依次启动server，client，feign，turbine这4个项目。 ####

![image][image 2]

#### 2. 访问turbine项目，[http://localhost:8764/hystrix][http_localhost_8764_hystrix] ####

输入 [http://localhost:8765/actuator/hystrix.stream][http_localhost_8765_actuator_hystrix.stream]  
，点击monitor stream  
![image][image 3]

#### 3. 可以看到监控界面，该界面处于loading状态，是因为feign没有访问相应的接口。 ####

访问feign相应的接口：[http://localhost:8765/hi?name=wsk][http_localhost_8765_hi_name_wsk]  
，可以看到相应的监控说明。  
![image][image 4]

*注*：一个接口一个图像

#### 4. 监控说明 ####

![image][image 5]

[https_wsk1103.github.io]: https://wsk1103.github.io/
[http_spring.io_projects_spring-cloud]: https://cloud.spring.io/spring-cloud-static/spring-cloud-netflix/2.1.0.M3/single/spring-cloud-netflix.html#_circuit_breaker_hystrix_clients
[https_cloud.spring.io_spring-cloud-static_Finchley.SR2_single_spring-cloud.html]: https://cloud.spring.io/spring-cloud-static/Finchley.SR2/single/spring-cloud.html
[image]: /images/20220404/062f60999e014bf893aac79095205666.png
[image 1]: /images/20220404/ceec9333e78748f7ab6afa83c4eab994.png
[https_github.com_wsk1103_my-spring-cloud]: https://github.com/wsk1103/my-spring-cloud
[image 2]: /images/20220404/986d6febae2448c685b2430a858b3568.png
[http_localhost_8764_hystrix]: http://localhost:8764/hystrix
[http_localhost_8765_actuator_hystrix.stream]: http://localhost:8765/actuator/hystrix.stream
[image 3]: /images/20220404/29fc536b8c244104a6333f02a839543b.png
[http_localhost_8765_hi_name_wsk]: http://localhost:8765/hi?name=wsk
[image 4]: /images/20220404/bd5717e06bee4389b1a2de312a3a3ce1.png
[image 5]: /images/20220404/20456313570e461eb5b5067e52df9a96.png