Ceki Gülcü wrote:
On 17/02/2010 11:19 AM, Per Lindberg wrote:It compiles and runs all right. But it doesn't change the log level. I have a log4j.properties that sets my default log level to INFO: log4j.rootLogger=WARN log4j.logger.com.facilitylabs.controlserver=INFO,SERVERLOG where SERVERLOG is a org.apache.log4j.RollingFileAppender. Works fine. Now, I have sprinkled my code with slf4j calls. Every method begins with log.debug("fooMethod({},{})", param1, param2); Now, suppose that I suspect that something is wrong in the running production server. I don't want to stop it, just tell it to start logging on DEBUG level for class com.facilitylabs.foo.barServlet . Via the web GUI I POST a command to the above code. But no debug messages are written to my log file. (INFO messages work fine, as usual). Is this because I change log level in the log4j layer, but not in the slf4j layer?You can't change the logging levels at the SLF4J layer because SLF4J does not keep its own levels, it delegates all decisions to the underlying logging framework. As for parametrized logging, if you look at the SLF4J code, you'll see that it asks the underlying logging framework whether to filter the message or not. In short, you can't set the level of loggers via the SLF4J API. So you should not worry about setting SLF4J levels.
Okay, that's nice. Does that mean that if I change the logging level to DEBUG at the LOG4J level, then calls to SLF4J log.debug() will start to output messages? (I have failed to make that work, but perhaps I have just overlooked some small detail...)
If you wish to change logging configuration at runtime, logback has support configuration file reloading which you might find useful: http://logback.qos.ch/manual/configuration.html#autoScan
But I can't modify any files in a running JEE web application. (And, besides, logback is not an option for me right now). Can't I just change the logging level by calling log4j logger.setLevel(level) ? Salutations, Per _______________________________________________ slf4j-user mailing list slf4j-user@qos.ch http://qos.ch/mailman/listinfo/slf4j-user
