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.

Your `pom.xml` section is a bit malformed, for example it is at least missing a `` at the start. I recommend to format for ease of human reading, e.g., make sure pastes are syntactically valid, and it also helps to reduce leading indentation. — AndrewF, Feb 11 '22 at 00:51

AndrewF · Answer 1 · 2022-02-11T01:08:04.750

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.

Logs are not getting generated with slf4j

1 Answers1