Log4j2 Slf4j Issue - logger files not getting created on server startup

ERROR StatusLogger Reconfiguration failed: No configuration found for '75b84c92' at 'null' in 'null'

The above is the error I am getting on server startup(netty).
The dependencies I am using are log4j-core-2.13.1, log4j-api-2.13.1, log4j-slf4j-impl-2.13.1 and slf4j-api-1.7.29

Log configuration has many aspects, but if you use Spring you do not need to do too many things for logging.

This is a basic pom.xml what you can use:

<?xml version="1.0" encoding="UTF-8"?>
<project ...>
    <modelVersion>4.0.0</modelVersion>
    <groupId>...</groupId>
    <artifactId>...</artifactId>
    <name>...</name>
    <packaging>...</packaging>
    <version>...</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.5.RELEASE</version>
    </parent>

    <properties>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
    </properties>

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

The Lombok plugin makes your life easier. If you use the @Slf4j annotation than you can use logger immediately: log.debug("say something").

Example code

@Slf4j
@Component
public class ClassA{
    public void doSomething() {
        log.debug("say something");
    }
}

The last thing that you can check is the log configuration in your application config file. You can use the following as a reference:

logging:
    level:
        root: INFO
        org.springframework: INFO
        com.a.b.c: DEBUG

Lets do it. There is less info in question so this give opportunity to me to explain in detail. Lets start.

Your pom.xml should look like this least

<properties>
	<spring.version>4.1.6.RELEASE</spring.version>
	<log4j.version>1.2.17</log4j.version>
</properties>

<dependencies>

	<!-- Spring -->
	<dependency>
		<groupId>org.springframework</groupId>
		<artifactId>spring-webmvc</artifactId>
		<version>${spring.version}</version>
	</dependency>

	<!-- Log4j -->
	<dependency>
		<groupId>log4j</groupId>
		<artifactId>log4j</artifactId>
		<version>${log4j.version}</version>
	</dependency>

</dependencies>

Create a log4j.properties file, and put it in the resources. folder

# Root logger option
log4j.rootLogger=DEBUG, stdout, file

# Redirect log messages to console
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n

# Redirect log messages to a log file
log4j.appender.file=org.apache.log4j.RollingFileAppender
#outputs to Tomcat home
log4j.appender.file.File=${catalina.home}/logs/myapp.log
log4j.appender.file.MaxFileSize=5MB
log4j.appender.file.MaxBackupIndex=10
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n

A simple controller to return a welcome page. Furthermore, it shows you how to use log4j to do the logging.

package com.kunal.common.controller;

import org.apache.log4j.Logger;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;

@Controller
public class WelcomeController {

	private static final Logger logger = Logger.getLogger(WelcomeController.class);

	@RequestMapping(value = "/", method = RequestMethod.GET)
	public ModelAndView getWelcome() {

		//logs debug message
		if(logger.isDebugEnabled()){
			logger.debug("getWelcome is executed!");
		}

		//logs exception
		logger.error("This is Error message", new Exception("Testing"));

		ModelAndView model = new ModelAndView("welcome");
		model.addObject("msg", "Hello Spring MVC + Log4j");
		return model;

	}

}

Let's run

mvn jetty:run (or whichever server you use)

and run URL http://localhost:8080/spring-mvc-log4j/

All message will appear in console

> log4j.properties

# Redirect log messages to console
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n

> Jetty console

2015-06-19 14:10:35 DEBUG WelcomeController:19 - getWelcome is executed!
2015-06-19 14:10:35 ERROR WelcomeController:23 - This is Error message
java.lang.Exception: Testing
        at com.kunal.common.controller.WelcomeController.getWelcome(WelcomeController.java:23)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:606)