How do I modify the WildFly 8 logging levels, specifically server.log. Currently I suspect they default to INFO and would like to change it to Debug or Error.
For reference I've been exploring these articles
https://docs.jboss.org/author/display/WFLY8/Logging+Configuration
https://docs.jboss.org/author/display/WFLY8/How+To
And suspect this is correct;
<subsystem xmlns="urn:jboss:domain:logging:2.0">
<console-handler name="CONSOLE">
<level name="DEBUG"/>
<formatter>
<named-formatter name="COLOR-PATTERN"/>
By default the console-handler is set to INFO and the FILE handler does not have a level set. The root-logger is also set to INFO.
The instructions on the How To page you link so you how to add a new logger via CLI and assign it a level. If you were to add a new logger at a DEBUG level, then the server.log would get those log messages written to it.
If you want to change the root-logger to see DEBUG messages for all loggers that are not defined you can execute the following command.
/subsystem=logging/root-logger=ROOT:write-attribute(name=level,value=DEBUG)
If you want to also see messages on the console you need to change the level on the handler.
/subsystem=logging/console-handler=CONSOLE:write-attribute(name=level,value=DEBUG)
I wouldn't advocate using editing the XML. Using a management interface such as CLI or the web console is the appropriate way to change server settings.
Just change the level of the root-logger and the one of the console logger. For a first shot this should work.
来源：https://stackoverflow.com/questions/26262702/wildfly-8-logging-levels