# bs-service-a

**Repository Path**: SpringCloudTestGroup/bs-service-a

## Basic Information

- **Project Name**: bs-service-a
- **Description**: No description available
- **Primary Language**: Unknown
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2018-11-26
- **Last Updated**: 2020-12-19

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# bs-service-a

#### 项目介绍

主要演示
feign 及 Hystrix 的机制的测试

通过
bs-service-a 通过 feign 访问 bs-service-b业务




#### 软件架构
软件架构说明


#### 安装教程

1. pom.xml

```
		<dependency>

			<groupId>org.springframework.cloud</groupId>

			<artifactId>spring-cloud-starter-openfeign</artifactId>

		</dependency>



		<dependency>

			<groupId>org.springframework.cloud</groupId>

			<artifactId>spring-cloud-starter-netflix-hystrix</artifactId>

		</dependency>


```



2. 程序入口

```
package com.example.a;



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.openfeign.EnableFeignClients;

import org.springframework.context.annotation.Configuration;



@SpringBootApplication

@EnableDiscoveryClient

@EnableFeignClients  `标记启用Feign功能`

@EnableCircuitBreaker `标记启用hystrix功能`

public class ServiceAApplication {



	public static void main(String[] args) {

		long starTime = System.currentTimeMillis();

		SpringApplication.run(ServiceAApplication.class, args);

		long endTime = System.currentTimeMillis();

		long time = endTime - starTime;

		System.out.println("\nStart Time: " + (time / 1000) + " s");

		System.out.println("...............................................................");

		System.out.println("..................Service starts successfully..................");

		System.out.println("...............................................................");

	}

}



```



3. application.yml or bootstrap.yml

 
```
hystrix:

  command:

    default:

      circuitBreaker:

        forceOpen: false

    #方法级的key

    "ServiceBClient#doGetFromB(String,Integer)":

      circuitBreaker:

        #设置窗口时间内的调用失败次数， 达到次数此窗口期内所有调用走fallback

        requestVolumeThreshold: 1

        #设置熔断观察窗口的时间

        sleepWindowInMilliseconds: 10000

      execution:

        isolation:

#          strategy: Semaphore

          thread:

            #设置超时时间

            timeoutInMilliseconds: 3000

      fallback:

        isolation:

          semaphore:

            maxConcurrentRequests: 1



  threadpool:

    #类级的key

    bs-service-b:

#    default:

       #线程池的配置

      coreSize: 10

      maximumSize: 10

      allowMaximumSizeToDivergeFromCoreSize: true

#      maxQueueSize: 1

#      queueSizeRejectionThreshold: 1





ribbon:

  ConnectTimeout: 10000

  ReadTimeout: 10000



feign:

  hystrix:

    enabled: true





eureka:

  client:

    registry-fetch-interval-seconds: 1


```

4. FeignClient

```
package com.example.a.client;



import com.example.a.fallback.ServiceBFallBack;

import org.springframework.cloud.openfeign.FeignClient;

import org.springframework.web.bind.annotation.*;



/**

 * Created by liuliyun-ds on 2018/6/27.

 */`访问服务器bs-service-b,并且有返回错误熔断处理机制`

@FeignClient(name = "bs-service-b", fallback = ServiceBFallBack.class)

public interface ServiceBClient {



    @RequestMapping(value = "/serviceB/test", method = RequestMethod.GET)

    String doGetFromB(@RequestParam(value = "arg") String arg, @RequestParam(value = "s") Integer s);

}



```
4. FallBack类型

```
package com.example.a.fallback;


import com.example.a.client.ServiceBClient;

import org.springframework.stereotype.Component;

import org.springframework.web.bind.annotation.RequestParam;



/**

 * Created by liuliyun-ds on 2018/11/26.

 */

@Component

public class ServiceBFallBack implements ServiceBClient{



    @Override`同接口方法,熔断处理机制后返回信息`

    public String doGetFromB(@RequestParam(value = "arg") String arg, @RequestParam(value = "s") Integer s){

        return "messageFromBFallback\n";

    }



}



```
5. 测试入口


```
package com.example.a.controller;


import com.example.a.client.ServiceBClient;

import com.example.a.client.ServiceCClient;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.beans.factory.annotation.Value;

import org.springframework.cloud.context.config.annotation.RefreshScope;

import org.springframework.web.bind.annotation.*;



import java.util.concurrent.ExecutorService;

import java.util.concurrent.Executors;





/**

 * Created by liuliyun-ds on 2018/11/9.

 */

@RestController

@RequestMapping("/serviceA")

@RefreshScope

public class AController {



    @Value("${test.message}")

    private String message;



    @Autowired

    private ServiceBClient serviceBClient;



    @Autowired

    private ServiceCClient serviceCClient;





    @GetMapping("/configTest")

    public String doGetMessage(){

//        return null;

        return message;

    }







    @GetMapping("/test")

    public String doGet(String arg, Integer s, String same, Integer index){

        String messageA = "messageFromA\n";



        Runnable runnable = new Runnable() {

            @Override

            public void run() {

               String message = serviceBClient.doGetFromB(arg, s);

                System.out.println("+++++++++++++++++++++" + message);

            }

        };



        if ("yes".equals(same)){

            ExecutorService executorService = Executors.newFixedThreadPool(10);

            for(int i = 0; i<5; i++){

                executorService.submit(runnable);

            }

            executorService.shutdown();

        }else {

            String messageB = serviceBClient.doGetFromB(arg, s);

            System.out.println("========================" + messageA + messageB);

            return messageA + messageB;

        }

        return messageA;

    }

}

```


```
spring-cloud-starter-sleuth 

跟踪原理：pom中依赖spring-cloud-starter-sleuth包后，每次链路请求都会添加一串追踪信息，格式是[server-name, main-traceId,sub-spanId,boolean]

第一个参数：服务结点名称；

第二个参数：一条链路唯一的ID，叫TraceID

第三个参数：链路中每一环的ID，叫做SpanID

第四个参数：是否将信息输出到Zipkin等服务收集和展示。

 

这种机制是如何实现的呢？我们知道Spring Framework微服务是通过http协议通信的（与之对立的是dubbo的RPC方式），所以Sleuth的实现也是基于http的，又不能影响正常的业务传递，所以能做文章的只能在http 的header上。

         Sleuth会在每个请求的header上添加跟踪需求的重要信息，例如：

X-B3-TraceId：对应TraceID；

X-B3-SpanId：对应SpanID；

X-B3-ParentSpanId：前面一环的SpanID；

X-B3-Sampled：是否被选中抽样输出；

X-Span-Name：工作单元名称。


x-b3-spanid
x-b3-parentspanid
x-b3-sampled
x-b3-traceid

以上参考:

牛麦康纳 https://blog.csdn.net/yejingtao703/article/details/78064066


logback.xml 参考

   <property name="CONSOLE_LOG_PATTERN"
              value="%clr(%d{yyyy-MM-dd HH:mm:ss.SSS}){faint} %clr(${LOG_LEVEL_PATTERN:-%5p}) %clr([${springAppName:-},%X{X-B3-TraceId:-},%X{X-B3-SpanId:-},%X{X-Span-Export:-}]){yellow} %clr(${PID:- }){magenta} %clr(---){faint} %clr([%15.15t]){faint} %clr(%-40.40logger{39}){cyan} %clr(:){faint} %m%n${LOG_EXCEPTION_CONVERSION_WORD:-%wEx}"/>

作者：楠倏之语
链接：https://www.jianshu.com/p/6d6b52c7624f
來源：简书
简书著作权归作者所有，任何形式的转载都请联系作者获得授权并注明出处。


```




#### 使用说明

1. xxxx
2. xxxx
3. xxxx

#### 参考贡献

1. 官网:[openfeign官网](http://cloud.spring.io/spring-cloud-openfeign/single/spring-cloud-openfeign.html)
2. 新建 Feat_xxx 分支
3. 提交代码
4. 新建 Pull Request