DWR depends on commons-logging and does all it's logging through that. For details on how to configure DWR logging, see the configuration information for the logging library that commons-logging is outputting to.
Out of the box, DWR is silent about method invocations and exceptions. If you turn debug logging on you will get some output, but the best way to see what is going on is to use a LogAjaxFilter. The simplest way to configure this is to use the following line in dwr.xml:
<dwr>
<allow>
<filter class="org.directwebremoting.filter.AuditLogAjaxFilter"/>
...
This functionality is available from milestone 2.
Debug logging can be enabled in DWR with the following:
log4j.logger.org.directwebremoting=DEBUG
See the log4j documentation for more details.
See the java.util.logging documentation for more details.