In PeopleSoft I know where I can find the log files and where I can find what information. In Oracle EBS it's not always clear for me where I can find what. Today the Applications Manager Log. It's not easy to find, it's in the Site Map of OAM, there is no direct navigation from the menu. You must first select a Responsibility from OAM, for example the Dashboard.
The information logged here is useful when you are trouble shooting connection issues. See the previous post and also Johan Louwers has an example of it. There are three log levels: USER, DEV and SUPPORT. I use DEV to troubleshoot. USER has very limited information. SUPPORT is useful to support for diagnosing problems.
It's described in the System Administrator's Guide - Maintenance, but it looks like the info is not accurate anymore. From the guide:
For a persistent setting, the log level
initialization parameter must be changed in zone.properties. The
parameter is: oracle.apps.oam.logger.level
There is no zone.properties file any more in release 12. But $ORACLE_HOME/sysman/webapps/emd/WEB-INF/web.xml contains the parameter oracle.apps.oam.logger.level, when changing it and bouncing the app. doesn't change the value, it's still USER at the Application Managers Log... Maybe I create a SR for this but for me it's not very useful to have it always on DEV, I prefer switching it to DEV when I need it.
The log files are stored at $LOG_HOME/appl/rgf/oam/