I'm working on PDI EE on tomcat 7, but the question may apply to BI-server or kettle-log4j plugin.
In my log4j.xml configuration file, I have defined a category/logger "org.pentaho.di" with additivity=false
and a specific file appender. The goal is to keep kettle logs in a file different from other stuffs.

the lines logged by this category are logged in the file, but are also logged in the root logger,
as if additivity was not respected, or as if there were a console appender somewere.

Can anyone help?

Second question:
Does anyone know what are the name of the loggers used by all the PDI stuffs?
Is there specific one for Carte, Repository, DB?
Moreover, do pdi use NDC/MDC?