第四篇(续)：熔断监控Hystrix Dashboard和熔断聚合监控Hystrix Turbine

Hystrix Dashboard：在微服务架构中为例保证程序的可用性，防止程序出错导致网络阻塞，出现了断路器模型。断路器的状况反应了一个程序的可用性和健壮性，它是一个重要指标。Hystrix Dashboard是作为断路器状态的一个组件，提供了数据监控和友好的图形化界面。

本篇基于第一篇的项目

创建service-client-dashboard

改造service-client，在pom文件中引入依赖

 <!--Eureka Client依赖-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
        <!--Web依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--actuator监控监控依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <!--hystrix-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
        </dependency>
        <!--hystrix dashboard-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-hystrix-dashboard</artifactId>
        </dependency>

编写配置文件application.yml

server:
  port: 8762
spring:
  application:
    name: eureka-client
eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/

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

在启动类添加@EnableHystrixDashboard注解， 开启HystrixDashboard

@SpringBootApplication
@EnableEurekaClient
@EnableHystrix 
@EnableHystrixDashboard
public class EurekaClientHystrixDashboardApplication {

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

}

修改controller层TestEurekaClient类

@RestController
public class TestEurekaClient {

    @Value("${server.port}")
    String port;

    @GetMapping("/test")
    @HystrixCommand(fallbackMethod = "hiError")
    public String home(@RequestParam(value = "name", defaultValue = "niuben") String name) {
        return "hi " + name + " ,现在的端口是:" + port;
    }

    public String hiError(String name) {
        return "hi, "+name+", error!";
    }
}

依次启动eureka-server 和service-client

浏览器，打开http://localhost:8762/actuator/hystrix.stream（在请求http://localhost:8762/actuator/hystrix.stream之前，需要随便请求一个接口，例如：http://localhost:8762/test，否则会一直ping ping ping）

在打开localhost:8762/hystrix，可以看见以下界面

依次输入http://localhost:8762/actuator/hystrix.stream 、2000 、test，出现以下界面

在另一个窗口请求http://localhost:8762/test?name=test，试试看

熔断聚合监控Hystrix Turbine

当我们有很多个服务的时候，这就需要聚合所以服务的Hystrix Dashboard的数据了

使用上面的工程

创建service-client-turbine模块

pom文件如下

 <!--Eureka Client依赖-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
        <!--Web依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--actuator监控监控依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <!--hystrix-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
        </dependency>
        <!--hystrix dashboard-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-hystrix-dashboard</artifactId>
        </dependency>
        <!--hystrix turbine-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-turbine</artifactId>
        </dependency>

编写配置文件application.yml

server:
  port: 8764
spring:
  application:
    name: eureka-client-turbine
eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/

management:
  endpoints:
    web:
      exposure:
        include: "*"
      cors:
        allowed-origins: "*"
        allowed-methods: "*"
turbine:
  app-config: eureka-client,eureka-clientTwo
  aggregator:
    clusterConfig: default
  clusterNameExpression: new String("default")
  combine-host: true
  instanceUrlSuffix:
    default: actuator/hystrix.stream

在启动类开启注解@EnableTurbine

@SpringBootApplication
@EnableEurekaClient
@EnableHystrix
@EnableHystrixDashboard
@EnableTurbine
public class EurekaClientHystrixTurbineApplication {

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

}

再复制service-client-turbine工程，命名为service-client-turbine-two（记得修改端口号）
依次启动eureka-server、service-client、service-client-turbine-two、service-client-turbine工程

浏览器打开:http://localhost:8763/hystrix；输入监控流http://localhost:8764/turbine.stream，点击monitor stream 进入页面，请求http://localhost:8762/test?name=ee，http://localhost:8763/test?name=ee

就可以看到这个页面聚合了2个service的hystrix dashbord数据了

源码：https://gitee.com/niugit_admin/spring-cloud-finchley