In the logging configuration that ships with the cassandra distribution
(log4j-server.properties in 2.0, and logback.xml in 2.1), the rolling file
appender is configured to print the file name and the line number of each
logging event:
log4j.appender.R.layout.ConversionPattern=%5p [%t] %d{ISO8601} %F (line %L)
%m%n
Both the log4j
<http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/PatternLayout.html>
and logback documentation <http://logback.qos.ch/manual/layouts.html> warn
that generating the filename/line information is not a cheap operation:
> Generating the file information is not particularly fast. Thus, its use
> should be avoided unless execution speed is not an issue.
The implementation for both involves creating a new Throwable and then printing
the stack trace for the throwable to find the file name or line number.
Is there a particular reason why the official distribution configures the
logging like this, instead of using the logger name (%c)?
Cassandra would seem like the perfect description of a place where execution
speed is an issue.
