On 5 Aug 2015, the Apache Foundation announced that Log4J 1, the popular logging framework, has been end-of-lifed, meaning that no future releases are expected and maintenance and support have been discontinued.
Migration to Log4J 2 is enabled through the use of a Log4J 1.X bridge, as described in a short FAQ about the EOL of Log4J 1:
Q: Is there a way to quickly migrate from Log4j 1.x to Log4j 2.x?
A: Yes, you can use the Log4j 1.x bridge http://logging.apache.org/log4j/2.x/log4j-1.2-api/index.html You must use this bridge without Log4j 1 jars in your application’s classpath. The bridge forwards all requests to Log4j 1 to Log4j 2.
Which logging framework do you prefer, and why?