Spring Cloud(四)《服务响应性能成功率监控 Hystrix》

2019/11/04

前言介绍

Hystrix Dashboard | 断路器仪表盘,Hystrix 依赖服务一段时间窗内的请求调用情况来判断并操作断路器的链接和熔断状态保护系统快速失败服务降级,而这些请求情况的指标信息都是 HystrixCommand 和 HystrixObservableCommand 服务实例在执行过程中记录的重要指标信息,它们除了 Hystrix 断路器实现中使用之外,对于系统运维也有非常大的帮助。这些指标信息会以 “滚动时间窗” 与 “桶” 结合的方式进行汇总,并在内存中驻留一段时间,以供内部或外部进行查询使用,Hystrix Dashboard 就是这些指标内容的消费者之一。

案例说明

结合上一章节案例,通过添加配置启动Hystrix Dashboard,来监控服务实时运行状态;服务信息、接口名、调用次数、响应时间、可用率、延迟、熔断状态等。

环境准备

  1. jdk 1.8
  2. Spring Boot 2.0.6.RELEASE
  3. Spring Cloud Finchley.SR2

代码示例

itstack-demo-springcloud-04
├── itstack-demo-springcloud-eureka-client
   └── src
       └── main
           ├── java
              └── org.itstack.demo
                   ├── web
                      └── EurekaClientController.java
                   └── EurekaClientApplication.java
           └── resources   
               └── application.yml
├── itstack-demo-springcloud-eureka-server
   └── src
       └── main
           ├── java
              └── org.itstack.demo
                   └── EurekaServerApplication.java
           └── resources   
               └── application.yml
├── itstack-demo-springcloud-hystrix-dashboard
   └── src
       └── main
           ├── java
              └── org.itstack.demo
                   └── DashboardApplication.java
           └── resources   
               └── application.yml
├── itstack-demo-springcloud-hystrix-feign
   └── src
       └── main
           ├── java
              └── org.itstack.demo
                   ├── service
                      ├── hystrix
                         └── FeignServiceHystrix.java
                      └── FeignService.java
                   ├── web
                      └── FeignController.java
                   └── FeignApplication.java
           └── resources   
               └── application.yml
└── itstack-demo-springcloud-hystrix-ribbon
    └── src
        └── main
            ├── java
               └── org.itstack.demo
                    ├── service
                       └── RibbonService.java
                    ├── web
                       └── RibbonController.java      
                    └── RibbonApplication.java
            └── resources   
                └── application.yml
**完整代码欢迎关注公众号:bugstack虫洞栈 回复“SpringCloud专题”进行下载**

itstack-demo-springcloud-eureka-client | 服务提供方

提供一个查询用户信息的简单方法,在配置文件中通过修改端口启动2次,模拟双实例应用,为调用方负载做准备。

web/EurekaClientController.java 注意@EnableEurekaClient用于向注册中心提供服务
/**
 * 微信公众号:bugstack虫洞栈 | 沉淀、分享、成长,专注于原创专题案例
 * 论坛:http://bugstack.cn
 * Create by 付政委 on @2019
 */
@EnableEurekaClient
@RestController
public class EurekaClientController {

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

    @RequestMapping(path = "/api/queryUserInfo", method = RequestMethod.GET)
    public String queryUserInfo(@RequestParam String userId) {
        return "Hi 微信公众号:bugstack虫洞栈 | " + userId + " >: from eureka client port: " + port;
    }

}
EurekaClientApplication.java 服务启动类
/**
 * 微信公众号:bugstack虫洞栈 | 沉淀、分享、成长,专注于原创专题案例
 * 论坛:http://bugstack.cn
 * Create by 付政委 on @2019
 */
@SpringBootApplication
public class EurekaClientApplication {

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

}
application.yml 配置文件链接服务注册中心,8001\8002分别配置启动
server:
  port: 8001 / 8002

spring:
  application:
    name: itstack-demo-springcloud-eureka-client

eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:7397/eureka/

itstack-demo-springcloud-eureka-server | 单个服务注册中心

服务注册中心用于承载接口提供方向上注册,同时正在调用方链接后可以获取指定应用的服务实例。

EurekaServerApplication.java 通过注解@EnableEurekaServer启动服务注册与发现中心

/**
 * 微信公众号:bugstack虫洞栈 | 沉淀、分享、成长,专注于原创专题案例
 * 论坛:http://bugstack.cn
 * Create by 付政委 on @2019
 */
@SpringBootApplication
@EnableEurekaServer
public class EurekaServerApplication {

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

}
application.yml 服务注册中心配置文件,端口7397和我们之前写netty的服务的端口一致
server:
  port: 7397

eureka:
  instance:
    hostname: localhost
  client:
    registerWithEureka: false
    fetchRegistry: false
    serviceUrl:
      defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/

spring:
  application:
    name: itstack-demo-springcloud-eureka-server

itstack-demo-springcloud-hystrix-dashboard | 服务监控像仪表盘一样透视系统健康度

Spring Cloud Hystrix Dashboard只是spring cloud基于Hystrix Dashboard,将实时监控数据通过页面呈现出来。Spring Cloud Hystrix Dashboard的底层原理是间隔一定时间去“Ping”目标服务,返回的结果是最新的监控数据,最后将数据显示出来。

Cluster via Turbine (default cluster): http://turbine-hostname:port/turbine.stream 
Cluster via Turbine (custom cluster): http://turbine-hostname:port/turbine.stream?cluster=[clusterName]
Single Hystrix App: http://hystrix-app:port/actuator/hystrix.stream 
DashboardApplication.java 配置@EnableHystrixDashboard启动服务
/**
 * 微信公众号:bugstack虫洞栈 | 沉淀、分享、成长,专注于原创专题案例
 * 论坛:http://bugstack.cn
 * Create by 付政委 on @2019
 */
@EnableHystrixDashboard
@SpringBootApplication
public class DashboardApplication {

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

}
application.yml 通用配置信息
server:
  port: 8989

spring:
  application:
    name: itstack-demo-springcloud-hystrix-dashboard

itstack-demo-springcloud-feign | Feign服务调用方,添加熔断Hystrix

Feign 是一个声明式的 Web Service 客户端,它的目的就是让 Web Service 调用更加简单。它整合了 Ribbon 和 Hystrix,从而让我们不再需要显式地使用这两个组件。Feign 还提供了 HTTP 请求的模板,通过编写简单的接口和插入注解,我们就可以定义好 HTTP 请求的参数、格式、地址等信息。接下来,Feign 会完全代理 HTTP 的请求,我们只需要像调用方法一样调用它就可以完成服务请求。

Feign 具有如下特性:

可插拔的注解支持,包括 Feign 注解和 JAX-RS 注解 支持可插拔的 HTTP 编码器和解码器 支持 Hystrix 和它的 Fallback 支持 Ribbon 的负载均衡 支持 HTTP 请求和响应的压缩

service/FeignService.java 注解方式调用,方便易用。@FeignClient会在调用时进行解析服务到具体的http://ip:port/
/**
 * 微信公众号:bugstack虫洞栈 | 沉淀、分享、成长,专注于原创专题案例
 * 论坛:http://bugstack.cn
 * Create by 付政委 on @2019
 */
@FeignClient(value = "itstack-demo-springcloud-eureka-client", fallback = FeignServiceHystrix.class)
public interface FeignService {

    @RequestMapping(value = "/api/queryUserInfo", method = RequestMethod.GET)
    String queryUserInfo(@RequestParam String userId);

}
service/hystrix/FeignServiceHystrix.java 提供熔断服务,当发生异常时主动返回预定结果
/**
 * 微信公众号:bugstack虫洞栈 | 沉淀、分享、成长,专注于原创专题案例
 * 论坛:http://bugstack.cn
 * Create by 付政委 on @2019
 */
@Component
public class FeignServiceHystrix implements FeignService {

    @Override
    public String queryUserInfo(String userId) {
        return "queryUserInfo by userId:" + userId + " err!from feign hystrix";
    }
    
}
web/FeignController.java 使用接口提供服务 From Feign
/**
 * 微信公众号:bugstack虫洞栈 | 沉淀、分享、成长,专注于原创专题案例
 * 论坛:http://bugstack.cn
 * Create by 付政委 on @2019
 */
@RestController
public class FeignController {

    @Resource
    private FeignService ribbonService;

    @RequestMapping(path = "/api/queryUserInfo", method = RequestMethod.GET)
    public String queryUserInfo(@RequestParam String userId) {
        return ribbonService.queryUserInfo(userId) + " From Feign";
    }

}
FeignApplication.java 注解@EnableEurekaClient、@EnableFeignClients、@EnableDiscoveryClient获取调用注册中心服务
/**
 * 微信公众号:bugstack虫洞栈 | 沉淀、分享、成长,专注于原创专题案例
 * 论坛:http://bugstack.cn
 * Create by 付政委 on @2019
 */
@SpringBootApplication
@EnableEurekaClient
@EnableDiscoveryClient
@EnableFeignClients
@EnableHystrix
public class FeignApplication {

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

}
application.yml eureka服务配置,从注册中心获取可用服务。开启hystrix=true,并设置hystrix.stream
server:
  port: 9001

spring:
  application:
    name: itstack-demo-springcloud-feign

eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:7397/eureka/

feign.hystrix.enabled: true

management:
  endpoints:
    web:
      exposure:
        include: hystrix.stream

itstack-demo-springcloud-ribbon | Ribbon服务调用方

Ribbon是一个基于 HTTP 和 TCP 的客户端负载均衡器。它可以通过在客户端中配置 ribbonServerList 来设置服务端列表去轮询访问以达到均衡负载的作用。

当 Ribbon 与 Eureka 联合使用时,ribbonServerList 会被 DiscoveryEnabledNIWSServerList 重写,扩展成从 Eureka 注册中心中获取服务实例列表。同时它也会用 NIWSDiscoveryPing 来取代 IPing,它将职责委托给 Eureka 来确定服务端是否已经启动。

service/RibbonService.java 接口式硬编码调用不太易于维护,因此也是比较少用的方式。hystrix实际通过getFallback()返回熔断结果
/**
 * 微信公众号:bugstack虫洞栈 | 沉淀、分享、成长,专注于原创专题案例
 * 论坛:http://bugstack.cn
 * Create by 付政委 on @2019
 */
@Service
public class RibbonService {

    @Autowired
    private RestTemplate restTemplate;

    @HystrixCommand(fallbackMethod = "queryUserInfoFallback")
    public String queryUserInfo(String userId) {
        return restTemplate.getForObject("http://ITSTACK-DEMO-SPRINGCLOUD-EUREKA-CLIENT/api/queryUserInfo?userId=" + userId, String.class);
    }

    /**
     * Specifies a method to process fallback logic.
     * A fallback method should be defined in the same class where is HystrixCommand.
     * Also a fallback method should have same signature to a method which was invoked as hystrix command.
     * for example:
     * <code>
     *      @HystrixCommand(fallbackMethod = "getByIdFallback")
     *      public String getById(String id) {...}
     *
     *      private String getByIdFallback(String id) {...}
     * </code>
     * Also a fallback method can be annotated with {@link HystrixCommand}
     * <p/>
     * default => see {@link com.netflix.hystrix.contrib.javanica.command.GenericCommand#getFallback()}
     *
     * @return method name
     *
     * getFallback()
     * 
     * @Override
     * protected Object getFallback() {
     *     final CommandAction commandAction = getFallbackAction();
     *     if (commandAction != null) {
     *         try {
     *             return process(new Action() {
     *                 @Override
     *                 Object execute() {
     *                     MetaHolder metaHolder = commandAction.getMetaHolder();
     *                     Object[] args = createArgsForFallback(metaHolder, getExecutionException());
     *                     return commandAction.executeWithArgs(metaHolder.getFallbackExecutionType(), args);
     *                 }
     *             });
     *         } catch (Throwable e) {
     *             LOGGER.error(FallbackErrorMessageBuilder.create()
     *                     .append(commandAction, e).build());
     *             throw new FallbackInvocationException(unwrapCause(e));
     *         }
     *     } else {
     *         return super.getFallback();
     *     }
     * }
     */
    public String queryUserInfoFallback(String userId) {
        return "queryUserInfo by userId:" + userId + " err!from ribbon hystrix";
    }

}
web/RibbonController.java 使用接口提供服务 From Ribbon
/**
 * 微信公众号:bugstack虫洞栈 | 沉淀、分享、成长,专注于原创专题案例
 * 论坛:http://bugstack.cn
 * Create by 付政委 on @2019
 */
@RestController
public class RibbonController {

    @Resource
    private RibbonService ribbonService;

    @RequestMapping(path = "/api/queryUserInfo", method = RequestMethod.GET)
    public String queryUserInfo(@RequestParam String userId) {
        return ribbonService.queryUserInfo(userId) + " From Ribbon";
    }
    
}
RibbonApplication.java 通过注解@LoadBalanced注册rest模版,用于Ribbon接口调用。并启动@EnableHystrix
/**
 * 微信公众号:bugstack虫洞栈 | 沉淀、分享、成长,专注于原创专题案例
 * 论坛:http://bugstack.cn
 * Create by 付政委 on @2019
 */
@SpringBootApplication
@EnableEurekaClient
@EnableDiscoveryClient
@EnableHystrix
public class RibbonApplication {

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

    @Bean
    @LoadBalanced
    RestTemplate restTemplate() {
        return new RestTemplate();
    }

}
application.yml eureka服务配置,从注册中心获取可用服务
server:
  port: 9002

spring:
  application:
    name: itstack-demo-springcloud-ribbon

eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:7397/eureka/

测试验证

  1. 启动itstack-demo-springcloud-hystrix-dashboard,访问;http://localhost:8989/hystrix 微信公众号:bugstack虫洞栈 & hystrix-dashboard 监控入口
  2. 测试监控
    1. 分别启动itstack-demo-springcloud-eureka-client、itstack-demo-springcloud-hystrix-feign与itstack-demo-springcloud-hystrix-ribbon
    2. http://localhost:8989/hystrix入口处填写;http://localhost:9001/actuator/hystrix.stream {也就是fegin调用接口}
    3. 刷新调用接口;http://localhost:9001/api/queryUserInfo?userId=111,观察监控页面{过程中讲服务提供方关闭} 微信公众号:bugstack虫洞栈 & 监控面板
  3. 也可以直接访问;http://localhost:9001/actuator/hystrix.stream,会收到ping监控数据

综上总结

  1. hystrix-dashboard 可以非常方便的实时监控系统健康度
  2. 实际开发过程中还有很多其他的监控系统,包括一些调用链路、系统可用率、jvm、gc等等
  3. 监控数据常常需要日志一起配合使用,才能更好的做到监控并查阅,尽快解决异常问题

上一篇:Spring Cloud(三)《应用服务快速失败熔断降级保护 Hystrix》

下一篇:Spring Cloud(五)《Turbine 监控信息聚合展示 Hystrix》

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(转载本站文章请注明作者和出处 微信公众号:bugstack虫洞栈 | 作者:付政委

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