Logs are not getting generated with slf4j

Question

I started facing issue since I have upgraded to 2.17.1 version , earlier my version was 2.1 and everything is working properly , since i have upgraded the version logs are not getting generated to log file
I have following configuration in my pom.xml

    <groupId>org.slf4j</groupId>
              <artifactId>log4j-over-slf4j</artifactId>
              <version>2.0.0-alpha6</version>
            </dependency>
         <dependency>
              <groupId>org.apache.logging.log4j</groupId>
              <artifactId>log4j-slf4j-impl</artifactId>
              <version>2.17.1</version>
            </dependency>
        <dependency>
              <groupId>org.apache.logging.log4j</groupId>
              <artifactId>log4j-api</artifactId>
              <version>2.17.1</version>
            </dependency>
        
        
            <dependency>
              <groupId>org.apache.logging.log4j</groupId>
              <artifactId>log4j-core</artifactId>
              <version>2.17.1</version>
            </dependency>

My logback.xml has following content:

    <?xml version="1.0" encoding="UTF-8"?>
            <Configuration status="warn" name="MyApp" packages="">
                <Appenders>
                    <RollingRandomAccessFile name="RollingRandomAccessFile" fileName="/lcc/lccapp/logs/lcc-publisher/producer.log"
                                             filePattern="/lcc/lccapp/logs/lcc-publisher/producer-%d{MM-dd-yyyy}-%i.zip" immediateFlush="false">
                        <PatternLayout>
                            <Pattern>%d %p %c{1.} [%t] %m%n</Pattern>
                        </PatternLayout>
                        <Policies>
                            <TimeBasedTriggeringPolicy interval="1" />
                        </Policies>
                        <DefaultRolloverStrategy max="100"/>
                    </RollingRandomAccessFile>
                </Appenders>
                <Loggers>
                    <Root level="info">
                        <AppenderRef ref="RollingRandomAccessFile"/>
                    </Root>
                </Loggers>
            </Configuration>

What i see in boot.log is:

    Starting the lcc-publisher application
    Application directory is /lcc/lccapp/apps/lcc-publisher
    SLF4J: No SLF4J providers were found.
    SLF4J: Defaulting to no-operation (NOP) logger implementation
    SLF4J: See http://www.slf4j.org/codes.html#noProviders for further details.
    SLF4J: Class path contains SLF4J bindings targeting slf4j-api versions prior to 1.8.
    SLF4J: Ignoring binding found at [jar:file:/lcc/lccapp/apps/lcc-publisher/lib/log4j-slf4j-impl-2.17.1.jar!/org/slf4j/impl/StaticLoggerBinder.class]
    SLF4J: See http://www.slf4j.org/codes.html#ignoredBindings for an explanation.
    Current dir using System:/lcc/lccapp/apps/tcc-publisher


    

Application is running without any issues , but logs are not getting written to log files.

Answer 1

Have you seen this page? Log4j 2 SLF4J Binding. Starting with Log4J 2.11.1, there are two separate implementations of Log4J 2's SLF4J binding, depending on your version of SLF4J.

Your use of log4j-over-slf4j version 2.0.0-alpha6 means your SLF4J API version (slf4j-api) is also 2.0.0-alpha6. Thus, according to the link above, you need to change your use of log4j-slf4j-impl to log4j-slf4j18-impl.

A couple of other things about the SLF4J version you're using:

• Are you sure you want to use SLF4J 2.x instead of 1.x? The fact that they are shipping a 2.x implies there are breaking changes in the API. So I don't think it can be guaranteed that any current version of Log4J is going to be compatible, especially since it's not finalized. 2.0.0 is still shipping alpha versions.
• Are you sure you want to use an alpha version of SLF4J instead of a stable release? Whatever works right now, it may break next time someone upgrades your SLF4J.

Incidentally, log4j-slf4j-impl brings in log4j-api transitively, so you should not need to explicitly declare log4j-api as a dependency. This is one fewer entry you need to manually maintain, and one fewer <version></version> you have to worry about keeping in sync.