log4j – Page 16 – Tarik Billa

How to stop INFO messages displaying on spark console?

October 13, 2022 by Tarik

Edit your conf/log4j.properties file and change the following line: log4j.rootCategory=INFO, console to log4j.rootCategory=ERROR, console Another approach would be to : Start spark-shell and type in the following: import org.apache.log4j.Logger import org.apache.log4j.Level Logger.getLogger(“org”).setLevel(Level.OFF) Logger.getLogger(“akka”).setLevel(Level.OFF) You won’t see any logs after that. Other options for Level include: all, debug, error, fatal, info, off, trace, trace_int, warn Details … Read more

In log4j, does checking isDebugEnabled before logging improve performance?

October 9, 2022 by Tarik

In this particular case, Option 1 is better. The guard statement (checking isDebugEnabled()) is there to prevent potentially expensive computation of the log message when it involves invocation of the toString() methods of various objects and concatenating the results. In the given example, the log message is a constant string, so letting the logger discard … Read more

How to initialize log4j properly?

September 29, 2022 by Tarik

Log4j by default looks for a file called log4j.properties or log4j.xml on the classpath. You can control which file it uses to initialize itself by setting system properties as described here (Look for the “Default Initialization Procedure” section). For example: java -Dlog4j.configuration=customName …. Will cause log4j to look for a file called customName on the … Read more

No appenders could be found for logger(log4j)?

September 16, 2022 by Tarik

This Short introduction to log4j guide is a little bit old but still valid. That guide will give you some information about how to use loggers and appenders. Just to get you going you have two simple approaches you can take. First one is to just add this line to your main method: BasicConfigurator.configure(); Second … Read more