dubbo服务链路跟踪方式

目前很多业务使用微服务架构，服务模块划分有这2种方式：

• 服务功能划分
• 业务划分

不管哪种方式，一次接口调用都需要多个服务协同完成，其中一个服务出现问题，都会导致最终失败，虽然有logback + kafka + ELK 这样的神器架构，但是定位问题也很麻烦，如果在整个链路中，可以通过一个唯一ID（traceId）跟踪本次服务调用，就可以在ELK中查找当前traceId来定位问题。

一、案例

1、案例结构

• pratices-demo-provider-core：定义服务接口
• pratices-demo-provider：具体实现
• pratices-demo-consumer-core：服务消费者，同时也是服务提供者
• pratices-demo-consumer：具体实现
• pratices-demo-web：提供http服务
• pratices-demo-trace：本案例的核心模块，在服务调用时拦截，设置traceId，跟踪本次服务调用

2、pratices-demo

2.1、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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <packaging>pom</packaging>
    <modules>
        <module>pratices-demo-consumer</module>
        <module>pratices-demo-provider</module>
        <module>pratices-demo-provider-core</module>
        <module>pratices-demo-consumer-core</module>
        <module>pratices-demo-web</module>
        <module>pratices-demo-trace</module>
    </modules>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.4.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.cn.dl</groupId>
    <artifactId>pratices-demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>pratices-demo</name>
    <description>Demo project for Spring Boot</description>

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

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-autoconfigure</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>dubbo</artifactId>
            <version>2.6.0</version>
            <exclusions>
                <exclusion>
                    <groupId>org.springframework</groupId>
                    <artifactId>spring</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>ch.qos.logback</groupId>
                    <artifactId>logback-core</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>ch.qos.logback</groupId>
                    <artifactId>logback-access</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>ch.qos.logback</groupId>
                    <artifactId>logback-classic</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.slf4j</groupId>
                    <artifactId>slf4j-api</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.apache.zookeeper</groupId>
            <artifactId>zookeeper</artifactId>
            <version>3.4.10</version>
        </dependency>
        <!--Exception in thread "main" java.lang.NoClassDefFoundError: org/I0Itec/zkclient/IZkStateListener-->
        <!--Caused by: java.lang.ClassNotFoundException: org.I0Itec.zkclient.IZkStateListener-->
        <dependency>
            <groupId>com.101tec</groupId>
            <artifactId>zkclient</artifactId>
            <version>0.10</version>
            <exclusions>
                <exclusion>
                    <artifactId>slf4j-log4j12</artifactId>
                    <groupId>org.slf4j</groupId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

    <repositories>
        <repository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/milestone</url>
        </repository>
        <repository>
            <id>spring-snapshots</id>
            <name>Spring Snapshots</name>
            <url>https://repo.spring.io/snapshot</url>
            <snapshots>
                <enabled>true</enabled>
            </snapshots>
        </repository>
    </repositories>
    <pluginRepositories>
        <pluginRepository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/milestone</url>
        </pluginRepository>
        <pluginRepository>
            <id>spring-snapshots</id>
            <name>Spring Snapshots</name>
            <url>https://repo.spring.io/snapshot</url>
            <snapshots>
                <enabled>true</enabled>
            </snapshots>
        </pluginRepository>
    </pluginRepositories>

</project>

3、pratices-demo-provider-core

3.1、ProviderService

package com.cn.dl;

/**
 * Created by yanshao on 2019-09-04.
 */
public interface ProviderService {
    String sayHello(String name);
}

4、pratices-demo-provider

4.1、ProviderServiceImpl

package com.cn.dl.provider.impl;

import com.alibaba.dubbo.config.annotation.Service;
import com.cn.dl.ProviderService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.slf4j.MDC;

/**
 * Created by yanshao on 2019-09-04.
 */
@Service
public class ProviderServiceImpl implements ProviderService {

    private static final Logger log = LoggerFactory.getLogger(ProviderServiceImpl.class);

    @Override
    public String sayHello(String name) {
        log.info("providerServiceImpl 服务提供 traceId:{},sayHello:{}", MDC.get("traceId"),name);
        return "hello " + name ;
    }
}

4.2、dubbo-provider.properties 配置文件

# dubbo-provider.properties
dubbo.application.name=service2
dubbo.registry.address=zookeeper://127.0.0.1:2181
dubbo.protocol.name=dubbo
dubbo.protocol.port=50010
dubbo.consumer.timeout=5000

4.3、ProviderMain服务启动类

注意：启动dubbo服务不需要暴露http服务

package com.cn.dl;

import com.alibaba.dubbo.config.spring.context.annotation.EnableDubbo;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.WebApplicationType;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.context.annotation.PropertySource;

import java.util.concurrent.locks.LockSupport;

/**
 * Created by yanshao on 2019-09-04.
 */
@EnableDubbo(scanBasePackages = "com.cn.dl*")
@PropertySource("classpath:/dubbo-provider.properties")
@SpringBootApplication
public class ProviderMain{

    private static final Logger log = LoggerFactory.getLogger(ProviderMain.class);
    /**
     * 启动dubbo服务，不需要提供web服务，但是默认有8080端口，通过一下方式可以不暴露web服务
     *
     * 1、在application.properties加上一下配置
     *
     * spring:
     *   main:
     *     allow-bean-definition-overriding: true
     *     web-application-type: none
     *
     * 2、修改启动类
     *  new SpringApplicationBuilder(ProviderMain .class)
     *                 .web(WebApplicationType.NONE)
     *                 .run(args)
     * */
    public static void main(String[] args)  {
        new SpringApplicationBuilder(ProviderMain.class).web(WebApplicationType.NONE).run(args);
        log.info("ProviderMain 启动了");
        LockSupport.park();
    }
}

@EnableDubbo(scanBasePackages = "com.cn.dl*")

扫描Dubbo的服务提供者以及Dubbo的服务消费者，一定要注意@EnableDubbo和@SpringBootApplication的先后次序；

@PropertySource("classpath:/dubbo-provider.properties")

加载配置文件到上下文环境变量。

5、pratices-demo-consumer-core

5.1、ConsumerService

package com.cn.dl;

/**
 * Created by yanshao on 2019-09-04.
 */
public interface ConsumerService {
    String toSayHello(String name);
    int getRandomInt();
}

6、pratices-demo-consumer

6.1、ConsumerServiceImpl

package com.cn.dl.consumer.impl;

import com.alibaba.dubbo.config.annotation.Reference;
import com.alibaba.dubbo.config.annotation.Service;
import com.cn.dl.ConsumerService;
import com.cn.dl.ProviderService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.slf4j.MDC;

import java.util.Random;

/**
 * Created by yanshao on 2019-09-04.
 */
@Service
public class ConsumerServiceImpl implements ConsumerService {

    private static final Logger log = LoggerFactory.getLogger(ConsumerServiceImpl.class);

    @Reference
    private ProviderService providerService;

    @Override
    public String toSayHello(String name) {
        String sayHello = providerService.sayHello(name);
        log.info("ConsumerServiceImpl >>>> traceId:{},sayHello:{}", MDC.get("traceId"),sayHello);
        return sayHello;
    }

    @Override
    public int getRandomInt() {
        return new Random().nextInt(100);
    }
}

6.2、dubbo-consumer.properties

dubbo.application.name=service1
dubbo.registry.address=zookeeper://127.0.0.1:2181
dubbo.protocol.name=dubbo
dubbo.protocol.port=50020
dubbo.consumer.timeout=5000

6.3、ConsumerMain

package com.cn.dl;

import com.alibaba.dubbo.config.spring.context.annotation.EnableDubbo;
import org.springframework.boot.WebApplicationType;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.context.annotation.PropertySource;

import java.util.concurrent.locks.LockSupport;

/**
 * Created by yanshao on 2019-09-04.
 */
@EnableDubbo(scanBasePackages = "com.cn.dl*")
@PropertySource("classpath:/dubbo-consumer.properties")
@SpringBootApplication
public class ConsumerMain {
    public static void main(String[] args) {
        new SpringApplicationBuilder(ConsumerMain.class).web(WebApplicationType.NONE).run(args);
        LockSupport.park();
    }
}

7、pratices-demo-web

7.1、WebTraceFilter

定义web拦截器，拦截所有请求，生成唯一ID

package com.cn.dl.webTrace;

import com.cn.dl.utils.TraceUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.slf4j.MDC;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

import static com.cn.dl.config.TraceConfig.TRACE_ID;

/**
 * Created by yanshao on 2019-09-04.
 */
public class WebTraceFilter implements Filter {

    private static final Logger log = LoggerFactory.getLogger(WebTraceFilter.class);

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        if (! (servletRequest instanceof HttpServletRequest) || ! (servletResponse instanceof HttpServletResponse)) {
            throw new ServletException("只支持http请求");
        }
        try {
            String traceId = TraceUtil.getTraceId();
            log.info("WebTraceFilter traceId:{}",traceId);
            MDC.put(TRACE_ID,traceId);
            filterChain.doFilter(servletRequest, servletResponse);
        } finally {
            MDC.remove(TRACE_ID);
        }
    }
}

7.2、TraceUtil

package com.cn.dl.utils;

import java.util.UUID;

/**
 * Created by yanshao on 2019-09-04.
 */
public class TraceUtil {

    public static String getTraceId(){
        return UUID.randomUUID().toString().replace("-","");
    }

    public static void main(String[] args) {
        System.out.println(getTraceId());
    }
}

7.3、TraceConfig

package com.cn.dl.config;

/**
 * Created by yanshao on 2019-09-04.
 */
public interface TraceConfig {
    String TRACE_ID = "traceId";
}

7.4、RpcProviderInterceptor

package com.cn.dl.rpcTrace;

import com.alibaba.dubbo.common.Constants;
import com.alibaba.dubbo.common.extension.Activate;
import com.alibaba.dubbo.rpc.*;
import com.cn.dl.utils.TraceUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.slf4j.MDC;
import org.springframework.util.StringUtils;

import java.util.Map;

import static com.cn.dl.config.TraceConfig.TRACE_ID;
/**
 * Created by yanshao on 2019-09-04.
 */
@Activate(group = Constants.PROVIDER)
public class RpcProviderInterceptor implements Filter {

    private static final Logger log = LoggerFactory.getLogger(RpcProviderInterceptor.class);

    @Override
    public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
        Result result;
        try {
            Map<String, String> at = invocation.getAttachments();
            MDC.put(TRACE_ID, ! StringUtils.isEmpty(at.get(TRACE_ID)) ? at.get(TRACE_ID): TraceUtil.getTraceId());
            result = invoker.invoke(invocation);
        } catch (Exception e) {
            log.error("RpcProviderInterceptor 异常",e);
            throw e;
        } finally {
            MDC.remove(TRACE_ID);
        }
        return result;
    }
}

7.5、RpcConsumerInterceptor

package com.cn.dl.rpcTrace;

import com.alibaba.dubbo.common.Constants;
import com.alibaba.dubbo.common.extension.Activate;
import com.alibaba.dubbo.rpc.*;
import com.cn.dl.utils.TraceUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.slf4j.MDC;

import java.util.Map;

import static com.cn.dl.config.TraceConfig.TRACE_ID;
/**
 * Created by yanshao on 2019-09-04.
 */
@Activate(group = Constants.CONSUMER)
public class RpcConsumerInterceptor implements Filter {

    private static final Logger log = LoggerFactory.getLogger(RpcProviderInterceptor.class);

    @Override
    public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
        Result result;
        try {
            Map<String, String> at = invocation.getAttachments();
            if (MDC.get(TRACE_ID) == null) {
                MDC.put(TRACE_ID,TraceUtil.getTraceId());
            }
            at.put(TRACE_ID, MDC.get(TRACE_ID));
            result = invoker.invoke(invocation);
        }catch (Exception e){
            log.error("RpcConsumerInterceptor 异常",e);
            throw e;
        }
        return result;
    }
}

7.6、RpcProviderInterceptor

package com.cn.dl.rpcTrace;

import com.alibaba.dubbo.common.Constants;
import com.alibaba.dubbo.common.extension.Activate;
import com.alibaba.dubbo.rpc.*;
import com.cn.dl.utils.TraceUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.slf4j.MDC;
import org.springframework.util.StringUtils;

import java.util.Map;

import static com.cn.dl.config.TraceConfig.TRACE_ID;
/**
 * Created by yanshao on 2019-09-04.
 */
@Activate(group = Constants.PROVIDER)
public class RpcProviderInterceptor implements Filter {

    private static final Logger log = LoggerFactory.getLogger(RpcProviderInterceptor.class);

    @Override
    public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
        Result result;
        try {
            Map<String, String> at = invocation.getAttachments();
            MDC.put(TRACE_ID, ! StringUtils.isEmpty(at.get(TRACE_ID)) ? at.get(TRACE_ID): TraceUtil.getTraceId());
            result = invoker.invoke(invocation);
        } catch (Exception e) {
            log.error("RpcProviderInterceptor 异常",e);
            throw e;
        } finally {
            MDC.remove(TRACE_ID);
        }
        return result;
    }
}

然后在resources下创建META-INF/dubbo/com.alibaba.dubbo.rpc.Filter，将扩展的拦截器添加到dubbo调用链中

consumerTraceFilter=com.cn.dl.rpcTrace.RpcConsumerInterceptor
providerTraceFilter=com.cn.dl.rpcTrace.RpcProviderInterceptor

8、pratices-demo-web

8.1、TraceInterceptor注册web拦截器

package com.cn.dl.config;

import com.cn.dl.webTrace.WebTraceFilter;
import org.springframework.boot.SpringBootConfiguration;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;

import javax.annotation.Resource;
import javax.servlet.Filter;

/**
 * Created by yanshao on 2019-09-04.
 */
@SpringBootConfiguration
public class TraceInterceptor {

    @Bean(name = "webTraceFilter")
    public WebTraceFilter getWebTraceFilter(){
       return new WebTraceFilter();
    }

    @Bean
    @Resource
    public FilterRegistrationBean traceFilterRegistration(Filter webTraceFilter) {
        FilterRegistrationBean<Filter> registration = new FilterRegistrationBean<>();
        registration.setFilter(webTraceFilter);
        registration.addUrlPatterns("/*");
        registration.setName("webTraceFilter");
        registration.setOrder(1);
        return registration;
    }
}

8.2、dubbo.properties

dubbo.application.name=consumer-service
dubbo.registry.address=zookeeper://127.0.0.1:2181
dubbo.consumer.timeout=5000

8.3、DemoWebController

package com.cn.dl.controller;

import com.alibaba.dubbo.config.annotation.Reference;
import com.cn.dl.ConsumerService;
import org.springframework.web.bind.annotation.*;

/**
 * Created by yanshao on 2019-09-04.
 */
@RestController
public class DemoWebController {

    @Reference
    private ConsumerService consumerService;

    @PostMapping("sayHello")
    public String sayHello(@RequestParam("name") String name){
        return consumerService.toSayHello(name);
    }

    @GetMapping("getRandomInt")
    public int getRandomInt(){
        return consumerService.getRandomInt();
    }

}

8.4、StartWeb

package com.cn.dl;

import com.alibaba.dubbo.config.spring.context.annotation.EnableDubbo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.PropertySource;

/**
 * Created by yanshao on 2019-09-04.
 */
@EnableDubbo(scanBasePackages = "com.cn.dl*")
@PropertySource("classpath:/dubbo.properties")
@SpringBootApplication
public class StartWeb {
    public static void main(String[] args) {
        SpringApplication.run(StartWeb.class,args);
    }
}

9、分别启动providerMain、consumerMain、startWeb

以上为个人经验，希望能给大家一个参考，也希望大家多多支持我们。