#Log4j log levels in decreasing order of severity
The FATAL level designates very severe error events that will presumably lead the application to abort.
The ERROR level designates error events that might still allow the application to continue running.
The WARN level designates potentially harmful situations.
The INFO level designates informational messages that highlight the progress of the application at coarse-grained level.
The DEBUG Level designates fine-grained informational events that are most useful to debug an application.
The TRACE Level designates finer-grained informational events than the DEBUG
The ALL has the lowest possible rank and is intended to turn on all logging.
The OFF has the highest possible rank and is intended to turn off logging.