Spring Cloud Hystrix Dashboard的使用 5.1.3

　　Hystrix除了可以对不可用的服务进行断路隔离外，还能够对服务进行实时监控。Hystrix可以实时、累加地记录所有关于HystrixCommand的执行信息，包括每秒执行多少、请求成功多少、失败多少等。
　　要想实时地对服务进行监控，需要在项目中添加相关的监控依赖，具体如下：

<dependency><!--监控依赖--><!--http://localhost:8030/hystrix.stream-->
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-actuator</artifactId>
</dependency>

　　在xcservice-eureka-user-hystrix工程的pom.xml中引入上述依赖后，即可查看监控信息，具体操作步骤如下。
　　（1）分别启动注册中心、服务提供者（7901）和服务消费者工程。
　　（2）通过浏览器访问地址http://localhost:8030/findOrder-sByUser/1（此步骤不可省略，否则将由于系统应用的所有接口都未被调用，而只输出ping:）。
　　（3）通过浏览器访问地址http://localhost:8030/hystrix.stream，将看到如下所示的输出信息。

ping: 

data: {"type":"HystrixCommand","name":"findOrdersByUser","group":"UserController","currentTime":1563192973047,"isCircuitBreakerOpen":false,"errorPercentage":0,"errorCount":0,"requestCount":0,"rollingCountBadRequests":0,"rollingCountCollapsedRequests":0,"rollingCountEmit":0,"rollingCountExceptionsThrown":0,"rollingCountFailure":0,"rollingCountFallbackEmit":0,"rollingCountFallbackFailure":0,"rollingCountFallbackMissing":0,"rollingCountFallbackRejection":0,"rollingCountFallbackSuccess":0,"rollingCountResponsesFromCache":0,"rollingCountSemaphoreRejected":0,"rollingCountShortCircuited":0,"rollingCountSuccess":0,"rollingCountThreadPoolRejected":0,"rollingCountTimeout":0,"currentConcurrentExecutionCount":0,"rollingMaxConcurrentExecutionCount":0,"latencyExecute_mean":0,"latencyExecute":{"0":0,"25":0,"50":0,"75":0,"90":0,"95":0,"99":0,"99.5":0,"100":0},"latencyTotal_mean":0,"latencyTotal":{"0":0,"25":0,"50":0,"75":0,"90":0,"95":0,"99":0,"99.5":0,"100":0},"propertyValue_circuitBreakerRequestVolumeThreshold":20,"propertyValue_circuitBreakerSleepWindowInMilliseconds":5000,"propertyValue_circuitBreakerErrorThresholdPercentage":50,"propertyValue_circuitBreakerForceOpen":false,"propertyValue_circuitBreakerForceClosed":false,"propertyValue_circuitBreakerEnabled":true,"propertyValue_executionIsolationStrategy":"THREAD","propertyValue_executionIsolationThreadTimeoutInMilliseconds":1000,"propertyValue_executionTimeoutInMilliseconds":1000,"propertyValue_executionIsolationThreadInterruptOnTimeout":true,"propertyValue_executionIsolationThreadPoolKeyOverride":null,"propertyValue_executionIsolationSemaphoreMaxConcurrentRequests":10,"propertyValue_fallbackIsolationSemaphoreMaxConcurrentRequests":10,"propertyValue_metricsRollingStatisticalWindowInMilliseconds":10000,"propertyValue_requestCacheEnabled":true,"propertyValue_requestLogEnabled":true,"reportingHosts":1,"threadPool":"UserController"}

data: {"type":"HystrixThreadPool","name":"UserController","currentTime":1563192973047,"currentActiveCount":0,"currentCompletedTaskCount":6,"currentCorePoolSize":10,"currentLargestPoolSize":6,"currentMaximumPoolSize":10,"currentPoolSize":6,"currentQueueSize":0,"currentTaskCount":6,"rollingCountThreadsExecuted":0,"rollingMaxActiveThreads":0,"rollingCountCommandRejections":0,"propertyValue_queueSizeRejectionThreshold":5,"propertyValue_metricsRollingStatisticalWindowInMilliseconds":10000,"reportingHosts":1}

　　可以看出，访问具体地址后，浏览器会不断地执行刷新操作以获取实时的监控数据。这样运维人员就可以通过这些数据来判断出系统当前的监控状态。虽然采用上面这种纯文字输出的方式可以实时监控数据，但其可读性十分差。
　　为此，我们可以通过Hystrix Dashboard以可视化的方式来查看实时监控数据。Hystrix Dashboard是Hystrix的一个组件，它提供了数据监控和友好的图形化界面支持。
　　下面通过一个具体的应用来演示Hystrix Dashboard的使用。
　　（1）新建xcservice-springcloud的子工程xcservice-hystrix-dashboard，在其pom.xml文件中添加监控依赖和Hystrix Dashboard依赖，如文件5-5所示。
　　文件5-5　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">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>com.xc</groupId>
        <artifactId>xcservice-springcloud</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>
    <groupId>com.xc</groupId>
    <artifactId>xcservice-hystrix-dashboard</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>xcservice-hystrix-dashboard</name>
    <description>Hystrix Dashboard是Hystrix的一个组件，它提供了数据监控和友好的图形化界面支持。</description>

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

    <dependencies>

        <dependency><!--数据监控和友好的图形化界面支持--><!--http://localhost:8031/hystrix.stream-->
            <groupId>org.springframework.cloud</groupId>
            <artifactId> spring-cloud-starter-hystrix-dashboard</artifactId>
        </dependency>

        <dependency><!--监控依赖--><!--http://localhost:8030/hystrix.stream-->
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</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>

　　（2）编写配置文件application.yml，指定应用的端口号和名称等信息，如文件5-6所示。
　　文件5-6　application.yml

server:
  port: 8031 # 指定该Eureka实例的端口号

spring:
  application:
    name: xcservice-hystrix-dashboard # 指定应用名称

　　（3）编写启动类Application.java，并在其类上添加@EnableHystrixDashboard注解来开启Hystrix仪表板功能，如文件5-7所示。
　　文件5-7　Application.java

package com.xc.xcservicehystrixdashboard;

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

@SpringBootApplication
@EnableHystrixDashboard
public class XcserviceHystrixDashboardApplication {

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

}

　　（4）启动工程后，通过浏览器访问地址http://local-host:8031/hystrix.stream将会看到如图5-8所示的信息。

　　在图5-8中，Hystrix Dashboard下的输入框用于输入需要监控的服务URL，Delay中的参数表示服务器上的轮询时间间隔，Title中的输入框用于设置浏览器中所监视服务的标题。
　　在Hystrix Dashboard下的输入框中输入http://localhost:8030/hystrix.stream，并设置Title为“订单微服务”后，单击【Monitor Stream】按钮。
　　此时如果通过另一个浏览器访问http://localhost:8030/findOrdersByUser/1，并且不断地刷新地址，将出现如下所示页面。