[logback-user] appenders

Sebastien Pennec sebastien at qos.ch
Thu Dec 21 18:11:41 CET 2006

Hello Eric,

Thanks for using logback :)

Appender threshold are not available in logback because the Appender class is in the 
core module, where there is no concept of level. However, like you correctly 
mentionned, the use of a filter can provide the functionnality that the threshold 

We are right in the process of testing filter performance. If the use of expression 
based filters is not satisfying in terms of speed, we will add a dedicated filter to 
cover this use case.

You can expect a more precised and detailled answer within the next 24 hours, once 
I've investigated further.



Eric Yung wrote:
> Hi,
> I have migrated from log4j to slf4j and logback. I have one question for 
> the appender setting. In log4j, you can set the threshold of an appender 
> so that only a certain level of log messages will be logged by that 
> appender. But in logback, I can only achieve this behavior by using a 
> expression filter. I would like to know the performance figure about 
> that filter. If the expression filter takes much longer than a dedicated 
> log level filter, I would like to see a simple log level filter be 
> included in logback.
> Thanks,
> Eric
> _______________________________________________
> Logback-user mailing list
> Logback-user at qos.ch
> http://qos.ch/mailman/listinfo/logback-user

Sébastien Pennec
sebastien at qos.ch

Logback: The reliable, generic, fast and flexible logging framework for Java.

More information about the Logback-user mailing list