The SAS logging facility provides six thresholds: TRACE,
DEBUG, INFO, WARN, ERROR, and FATAL. Thresholds are used to ignore
log events that are lower than a particular level, or to filter messages
so that only a single message level is logged.
When a log event occurs,
up to three levels of filtering can take place:
-
filtering log events
by comparing the log event level to the log event's logger level
-
filtering log events
by comparing the log event level to the appender's threshold
-
filtering log events
by comparing the log event level to the threshold that is specified
in the filter definition, which is a part of the appender configuration
In the first two cases,
if the log event level is lower than the logger or appender threshold,
the logging facility ignores the log event. Otherwise, processing
of the log event continues.
In the third case, the
log event level is compared to the filter threshold. If there is a
match, the log event can be either accepted or denied. If there is
no match, the filtering process continues to the next filter in the
filtering policy. For more information, see
Filters. The logging levels,
from the lowest to the highest, are as follows:
TRACE
produces the most detailed
information about your application. This level is primarily used by
SAS Technical Support or development.
DEBUG
produces detailed information
that you use to debug your application. This level is primarily used
by SAS Technical Support or development.
INFO
provides information
that highlights the progress of an application.
WARN
provides messages that
identify potentially harmful situations.
ERROR
provides messages that
indicate that errors have occurred. The application might continue
to run.
FATAL
provides messages that
indicate that severe errors have occurred. These errors will probably
cause the application to end.
Requirement: The level
must be enclosed in quotation marks.
An appender can be configured
to have a threshold. By default, however, appenders do not have a
threshold. When set, all log events that have a level lower than the
threshold are ignored by the appender.