Hi, I'm in the (hardly unique, apparently :-) position of trying to decide how to address some problems that my company's home-grown logging module has. log4j has lots of very cool features, so I'm tempted to switch over, but I'm not sure whether I've figured out some of the concepts, quite.
My main question has to do with how log4j achieves its "method invocation plus an integer comparison" efficiency when I've got several dynamically-configured appenders, on the same logger or perhaps on ancestor/descendant loggers. The behavior I'd expect is that every appender has a set of filters associated with it (that would most commonly look at level only) and that log4j would take care of setting the level of each logger instance based on what appenders that logger had to support. But I can't find any documentation or log4j source code that talks about that, so what I'm thinking instead is that appenders can do whatever funky filtering they want to, and loggers can filter based on effective level, and the only relationship between these two layers of filtering (appender and logger) is that a message gets through only if it passes both tests. Is that right? If so, has anyone thought about or coded a facility that would take a look at all of the appender levels, and "precompute" the logger levels whenever the appender/level configuration changes so that messages could be filtered efficiently (i.e., "isGreaterOrEqual(this.getEffectiveLevel())") at the logger stage? Right now, if I were to set logger levels based on what one appender (a statically-configured FileAppender, say) needed, I don't see how I could effectively keep that setting from conflicting with what made sense for another appender (like a dynamically-attached SocketAppender, for instance). I get the feeling that maybe I'm confused because I'm trying to think about log4j in the same terms as the logging code I'm used to, and they don't work quite the same. Or maybe this does make sense in log4j and has already been implemented, or isn't implemented yet but would be cool. Any thoughts? -g. -- To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
