Spring Boot - Tracing Micro Service Logs

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Most developers face difficulty of tracing logs if any issue occurred. This can be solved by Spring Cloud Sleuth and ZipKin server for Spring Boot application.

Note* - Spring Cloud Sleuth is not supported in Spring Boot 3 and is moved to a distributed version micrometer.

Spring Cloud Sleuth

Spring cloud Sleuth logs are printed in the following format −

[application-name,traceid,spanid,zipkin-export]

Where,

• Application-name = Name of the application

• Traceid = each request and response traceid is same when calling same service or one service to another service.

• Spanid = Span Id is printed along with Trace Id. Span Id is different every request and response calling one service to another service.

• Zipkin-export = By default it is false. If it is true, logs will be exported to the Zipkin server.

Now, add the Spring Cloud Starter Sleuth dependency in your build configuration file as follows −

Maven users can add the following dependency in your pom.xml file −

<dependency>
   <groupId>org.springframework.cloud</groupId>
   <artifactId>spring-cloud-starter-sleuth</artifactId>
</dependency>

Gradle users can add the following dependency in your build.gradle file −

compile('org.springframework.cloud:spring-cloud-starter-sleuth')

Now, add the Logs into your Spring Boot application Rest Controller class file as shown here −

package com.tutorialspoint.sleuthapp;

import java.util.logging.Level;
import java.util.logging.Logger;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
@RestController
public class SleuthappApplication {
   private static final Logger LOG = Logger.getLogger(SleuthappApplication.class.getName());
   public static void main(String[] args) {
      SpringApplication.run(SleuthappApplication.class, args);
   }
   @GetMapping("/")
   public String index() {
      LOG.log(Level.INFO, "Index API is calling");
      return "Welcome Sleuth!";
   }
}

Now, add the application name in application.properties file as shown −

spring.application.name = tracinglogs

The complete code for build configuration file is given below −

Maven 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>
   <groupId>com.tutorialspoint</groupId>
   <artifactId>sleuthapp</artifactId>
   <version>0.0.1-SNAPSHOT</version>
   <packaging>jar</packaging>

   <name>sleuthapp</name>
   <description>Demo project for Spring Boot</description>

   <parent>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-parent</artifactId>
      <version>1.5.9.RELEASE</version>
      <relativePath/> <!-- lookup parent from repository -->
   </parent>

   <properties>
      <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
      <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
      <java.version>1.8</java.version>
      <spring-cloud.version>Edgware.RELEASE</spring-cloud.version>
   </properties>

   <dependencies>
      <dependency>
         <groupId>org.springframework.cloud</groupId>
         <artifactId>spring-cloud-starter-sleuth</artifactId>
      </dependency>
      <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>
   </dependencies>

   <dependencyManagement>
      <dependencies>
         <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-dependencies</artifactId>
            <version>${spring-cloud.version}</version>
            <type>pom</type>
            <scope>import</scope>
         </dependency>
      </dependencies>
   </dependencyManagement>

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

Gradle build.gradle

buildscript {
   ext {
      springBootVersion = '3.3.3'
   }
   repositories {
      mavenCentral()
   }
   dependencies {
      classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
   }
}

apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'org.springframework.boot'

group = 'com.tutorialspoint'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = 21

repositories {
   mavenCentral()
}
ext {
   springCloudVersion = 'Edgware.RELEASE'
}
dependencies {
   compile('org.springframework.cloud:spring-cloud-starter-sleuth')
   compile('org.springframework.boot:spring-boot-starter-web')
   testCompile('org.springframework.boot:spring-boot-starter-test')
}
dependencyManagement {
   imports {
      mavenBom "org.springframework.cloud:spring-cloud-dependencies:${springCloudVersion}"
   }
}

Compilation and Execution

You can create an executable JAR file, and run the Spring Boot application by using the following Maven or Gradle commands.

For Maven, you can use the following command −

mvn clean install

After "BUILD SUCCESS", you can find the JAR file under the target directory.

For Gradle, you can use the following command −

gradle clean build

After "BUILD SUCCESSFUL", you can find the JAR file under the build/libs directory.

Now, run the JAR file by using the command shown here −

java jar <JARFILE> 

Now, the application has started on the Tomcat port 8080.

Now, hit the URL in your web browser and see the output in console log.

http://localhost:8080/

You can see the following logs in the console window. Observe that log is printed in the following format [application-name, traceid, spanid, zipkin-export]