SpringCloud Sleuth分布式请求链路追踪

1.1 为什么会出现这个技术？需要解决哪些问题？

在微服务框架中，一个由客户端发起的请求在后端系统中会经过多个不同的服务节点调用来协同产生最后的请求结果，每一个前段请求都会形成一条复杂的分布式服务调用链路，链路中的任何一环出现高延时或错误都会引起整个请求最后的失败。

1.2 是什么

https://github.com/spring-cloud/spring-cloud-sleuth

Spring Cloud Sleuth提供了一套完整的服务跟踪解决方案

在分布式系统中提供追踪解决方案并且兼容支持了zipkin

1.3 解决

2.1 zipkin

SpringCloud从F版起已不需要自己构建Zipkin server了，只需要调用jar包即可

https://dl.bintray.com/openzipkin/maven/io/zipkin/java/zipkin-server/

zipkin-server-2.12.9.exec.jar

2.1.1 运行jar

java -jar zipkin-server-2.12.9.exec.jar

2.1.2 运行控制台

http://localhost:9411/zipkin/

术语

完整的调用链路

名词解释

Trace:类似于树结构的Span集合，表示一条调用链路，存在唯一标识。

span：表示调用链路来源，通俗的理解span就是一次请求信息。

2.2 服务提供者

cloud-provider-payment8001

2.2.1 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">     <parent>         <artifactId>cloud2020</artifactId>         <groupId>com.atguigu.springcloud</groupId>         <version>1.0-SNAPSHOT</version>     </parent>     <modelVersion>4.0.0</modelVersion>      <artifactId>cloud-provider-payment8001</artifactId>      <dependencies>         <!--包含了sleuth+zipkin-->         <dependency>             <groupId>org.springframework.cloud</groupId>             <artifactId>spring-cloud-starter-zipkin</artifactId>         </dependency>          <dependency>             <groupId>org.springframework.cloud</groupId>             <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>         </dependency>          <dependency>             <groupId>com.atguigu.springcloud</groupId>             <artifactId>cloud-api-commons</artifactId>             <version>${project.version}</version>         </dependency>           <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-web -->         <dependency>             <groupId>org.springframework.boot</groupId>             <artifactId>spring-boot-starter-web</artifactId>         </dependency>          <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-web -->         <dependency>             <groupId>org.springframework.boot</groupId>             <artifactId>spring-boot-starter-actuator</artifactId>         </dependency>          <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-web -->         <dependency>             <groupId>org.mybatis.spring.boot</groupId>             <artifactId>mybatis-spring-boot-starter</artifactId>         </dependency>          <!-- https://mvnrepository.com/artifact/com.alibaba/druid -->         <dependency>             <groupId>com.alibaba</groupId>             <artifactId>druid-spring-boot-starter</artifactId>             <version>1.1.10</version>         </dependency>         <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->         <dependency>             <groupId>mysql</groupId>             <artifactId>mysql-connector-java</artifactId>         </dependency>          <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-jdbc -->         <dependency>             <groupId>org.springframework.boot</groupId>             <artifactId>spring-boot-starter-jdbc</artifactId>         </dependency>          <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-devtools -->         <dependency>             <groupId>org.springframework.boot</groupId>             <artifactId>spring-boot-devtools</artifactId>             <scope>runtime</scope>             <optional>true</optional>         </dependency>          <!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->         <dependency>             <groupId>org.projectlombok</groupId>             <artifactId>lombok</artifactId>             <optional>true</optional>         </dependency>          <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-test -->         <dependency>             <groupId>org.springframework.boot</groupId>             <artifactId>spring-boot-starter-test</artifactId>             <scope>test</scope>         </dependency> <!--        <dependency>--> <!--            <groupId>org.springframework.cloud</groupId>--> <!--            <artifactId>spring-cloud-gateway-core</artifactId>--> <!--        </dependency>-->       </dependencies>   </project>

2.2.2 YML

server:   port: 8001   spring:   application:     name: cloud-payment-service   zipkin:     base-url: http://localhost:9411   sleuth:     sampler:       #采样率值介于0到1之间，1则表示全部采集       probability: 1   datasource:     type: com.alibaba.druid.pool.DruidDataSource     driver-class-name: org.gjt.mm.mysql.Driver  # mysql驱动包     url: jdbc:mysql://localhost:3306/cloud2020?useUnicode=true&characterEncoding=utf-8&useSSL=false     username: root     password: root  eureka:   client:     #表示是否将自己注册进EurekaServer默认为true     register-with-eureka: true     #是否从EurekaServer抓取已有的注册信息，默认为true。单节点无所谓，集群必须设置为true才能配合ribbon使用负载均衡     fetchRegistry: true     service-url: #      defaultZone: http://localhost:7001/eureka #单机版       defaultZone: http://eureka7001.com:7001/eureka,http://eureka7002.com:7002/eureka#集群版   instance:     instance-id: payment8001     #访问路径可以显示IP地址     prefer-ip-address: true     #Eureka客户端向服务端发送心跳的时间间隔，单位为妙（默认是30秒)     lease-renewal-interval-in-seconds: 1     #Eureka服务端在收到最后一次心跳后等待时间上限，单位为秒（默认是90秒），超时将剔除服务     lease-expiration-duration-in-seconds: 2    mybatis:   mapperLocations: classpath:mapper/*.xml   type-aliases-package: com.atguigu.springcloud.entities #所有Entity别名类所在包

2.2.3业务类PyamentController

package com.atguigu.springcloud.controller;  import com.atguigu.springcloud.entities.CommonResult; import com.atguigu.springcloud.entities.Payment; import com.atguigu.springcloud.service.PaymentService; import lombok.extern.slf4j.Slf4j; import org.springframework.beans.factory.annotation.Value; import org.springframework.cloud.client.ServiceInstance; import org.springframework.cloud.client.discovery.DiscoveryClient; import org.springframework.web.bind.annotation.*;  import javax.annotation.Resource; import java.util.List; import java.util.concurrent.TimeUnit;  @RestController @Slf4j public class PaymentController {      @Resource     private PaymentService paymentService;      @Value("${server.port}")     private String serverPort;      @Resource     private DiscoveryClient discoveryClient;      @GetMapping(value = "/payment/discovery")     public Object discovery() {         List<String> services = discoveryClient.getServices();         for (String element : services) {             log.info("********element: " + element);         }         List<ServiceInstance> instances = discoveryClient.getInstances("CLOUD-PAYMENT-SERVICE");         for (ServiceInstance instance : instances) {             log.info(instance.getServiceId()+"\t"+instance.getHost()+"\t"+instance.getPort()+"\t"+instance.getUri());         }         return this.discoveryClient;     }      @GetMapping(value = "/payment/lb")     public String getPaymentLB() {         return serverPort;     }      @PostMapping(value = "/payment/create")     public CommonResult create(@RequestBody Payment payment) {         int result = paymentService.create(payment);         log.info("*****插入结果：" + result + "****哈哈");         if (result > 0) {  //成功             return new CommonResult(200, "插入数据库成功,serverPort: " + serverPort, result);         } else {             return new CommonResult(444, "插入数据库失败", null);         }     }      @GetMapping(value = "/payment/get/{id}")     public CommonResult<Payment> getPaymentById(@PathVariable("id") Long id) {         Payment payment = paymentService.getPaymentById(id);         log.info("*****查询结果：" + payment + "哈哈哈");         if (payment != null) {  //说明有数据，能查询成功             return new CommonResult(200, "查询成功,serverPort: " + serverPort, payment);         } else {             return new CommonResult(444, "没有对应记录，查询ID：" + id, null);         }     }      @GetMapping(value = "/payment/feign/timeout")     public String paymentFeignTimeout() {         try {             TimeUnit.SECONDS.sleep(3);         } catch (InterruptedException e) {             e.printStackTrace();         }         return serverPort;     }      @GetMapping("/payment/zipkin")     public String paymentZipkin() {         return "hi, I'm paymentZipkin server fall back, welcome to here";     } }

2.3 服务消费者(调用方)

cloud-consumer-order80

2.3.1 POM

 <!--包含了sleuth+zipkin-->         <dependency>             <groupId>org.springframework.cloud</groupId>             <artifactId>spring-cloud-starter-zipkin</artifactId>         </dependency>

2.3.2 YML

server:   port: 80  spring:   application:     name: cloud-order-service   zipkin:     base-url: http://localhost:9411   sleuth:     sampler:       #采样率值介于0到1之间，1则表示全部采集       probability: 1  eureka:   client:     #表示是否将自己注册进EurekaServer默认为true     register-with-eureka: true     #是否从EurekaServer抓取已有的注册信息，默认为true。单节点无所谓，集群必须设置为true才能配合ribbon使用负载均衡     fetchRegistry: true     service-url:       #      defaultZone: http://localhost:7001/eureka #单机版       defaultZone: http://eureka7001.com:7001/eureka,http://eureka7002.com:7002/eureka#集群版

2.3.3 业务类PaymentController

package com.atguigu.springcloud.controller;  import com.atguigu.springcloud.entities.CommonResult; import com.atguigu.springcloud.entities.Payment; import lombok.extern.slf4j.Slf4j; import org.springframework.http.ResponseEntity; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RestController; import org.springframework.web.client.RestTemplate;  import javax.annotation.Resource;  @RestController @Slf4j public class OrderController {     //不能写死 //    public static final String PAYMENT_URL = "http://localhost:8001";     //注册中心上获取     public static final String PAYMENT_URL = "http://CLOUD-PAYMENT-SERVICE";      @Resource     private RestTemplate restTemplate;      @GetMapping("/consumer/payment/create")     public CommonResult<Payment> create(Payment payment) { //        return restTemplate.postForObject(PAYMENT_URL + "/payment/create", payment, CommonResult.class);         return restTemplate.postForEntity(PAYMENT_URL+"/payment/create", payment, CommonResult.class).getBody();     }  //    返回对象为响应体中数据转化成的对象，基本上可以理解为Json     @GetMapping("/consumer/payment/get/{id}")     public CommonResult<Payment> getPayment(@PathVariable("id") Long id) {         return restTemplate.getForObject(PAYMENT_URL + "/payment/get/" + id, CommonResult.class);     }  //    返回对象为ResponseEntity对象，包含了响应中的一些重要信息，比如响应头、响应状态码、响应体等     @GetMapping("/consumer/payment/getForEntity/{id}")     public CommonResult<Payment> getPayment2(@PathVariable("id") Long id) {         ResponseEntity<CommonResult> entity = restTemplate.getForEntity(PAYMENT_URL + "/payment/get/" + id, CommonResult.class);         if (entity.getStatusCode().is2xxSuccessful()) {             log.info(entity.getStatusCode()+"\t"+entity.getHeaders());             CommonResult body = entity.getBody();             return body;         } else {             return new CommonResult<>(444, "操作失败");         }     }      // ====================> zipkin+sleuth     @GetMapping("/consumer/payment/zipkin")     public String paymentZipkin()     {         String result = restTemplate.getForObject("http://localhost:8001"+"/payment/zipkin/", String.class);         return result;     }   }