Log4J Dependency with Kafka

Many of the Kafka artifacts have Log4J dependencies. If you are using logback then your logging stops all of a sudden. Here is an example for one of our sample app. Here we have added such dependency and the App seems to have issues with multiple SL4J bindings. It has finally picked up Log4J instead.

If we look at this log, clearly the other binding is coming from Log4J. If we look at the Project tab, we can also see log4J artifact being added here.

log4j dependency

Here is our current build.sbt. It has “io.confluent” % “kafka-avro-serializer” % “1.0”, which is pulling up log4J as a dependency.

The solution is simple. We just need to tell SBT not to pull Log4J as dependency of this library.

And now we can see that the artifact for Log4J is removed from the external libraries.

log4j dependency exclusion