How to use "Level" and "Category" configurations in log4j.xml to add more flexibility in the Application logging

QUESTION

ANSWER

In the attached samplelog4japplication three configurations can help realize the discussed flexibility. Check and change the log4j.xml for understanding the differences

1. "Mule Default logger" is the default configuration in the Mule application. In this setting, any logger component with "INFO" would get printed. [Note: The component "printOnlyInDEBUGMode" in the application would not get printed in this configuration]
2. When the log4j.xml is modified for "Configuration - 1" only the logger component "printOnlyInDEBUGMode" would get printed
3. When the log4j.xml is modified for "Configuration - 2" only "beforeDataWeave" and "afterDataWeave" payload would get printed.

ADDITIONAL INFORMATION

As you are probably aware, logging is a costly operation in any application. It involves IO and/or other related functions while the actual transaction is being processed. Too much of it could potentially delay the message processing time, too little of it can mean less detail about the transaction and its processing status. Following are the additional features in log4j that can add flexibility in logging configurations

1. The "Level" when set in logger components gets printed when set for that level in log4j XML configuration. This way the number of logger statements in the application can be regulated as per the need. [Eg., Not all the statements need to be in INFO status, few of them can be in DEBUG so that one can enable it during the process of troubleshooting and disable it when not required]
2. The "Category" groups sets of logger components. This way the level of all the logger components for a particular category can be controlled with a single log4j XML configuration[Have a set of logger statements grouped into a category. Each category can have a log level.]