Understanding logging levels

Each log message has an associated log level that gives a rough guide to the importance and urgency of the message. Each level has an associated integer value usable by rules that monitor system messages. Higher values indicate higher priorities. As such, a rule might look for Error and Fatal messages by looking for values greater than or equal to 40,000 (Level>=40000).
Level Value Description
Inherit Not applicable Inherit the level from the parent logger.
Off Not applicable No logging.
Fatal 50,000 Very severe error events that might cause the application to terminate.
Error 40,000 Error events of considerable importance that will prevent normal program execution, but might still allow the application to continue running.
Warn 30,000 Potentially harmful situations of interest to end users or system managers that indicate potential problems.
Info 20,000 Informational messages that might make sense to end users and system administrators, and highlight the progress of the application.
Debug 10,000 Relatively detailed tracing used by application developers. The exact meaning of the three debug levels varies among subsystems.
Debug - Low 9,000 Information broadly interesting to developers who do not have a specialized interest in the specific subsystem. Might include minor (recoverable) failures and issues indicating potential performance problems.
Debug - Medium 8,000 Fairly detailed tracing messages. Calls for entering, returning, or throwing an exception are traced at this level.
Debug - High 7,000 Highly detailed tracing messages. Produces the most voluminous output.
All Not applicable All messages.

You might want to increase the logging level of a logger to diagnose or debug a problem. The default level for all loggers is Inherit, and the default level for the root logger is Info.

Do not turn on Debug or higher logging without direction from technical support. Turning on this excessive logging for high volume module like system, query, or exec can rapidly flood your system and terminate the servers.