Oracle ATG Web Commerce platform configuration layers allow you to make configuration changes and preserve them locally, without modifying the base configuration. Layers contain properties files, and can be stacked in a variety of ways to create different configurations for different purposes. The configuration stack is determined from the MANIFEST.MF files for the Oracle ATG Web Commerce application modules included in the application.
Nucleus locates configuration properties by examining the properties files in the directories and JAR files specified by the configuration path or paths (a module can have any number of configuration paths). The paths for all modules used in your application are aggregated and ordered based on the module dependencies. The result is a combination of the property values found in each of the files or directories in the configuration paths. If the same property value is defined in more than one properties file, values found later in the configuration path (as determined by the module dependencies) override the values found earlier. The localconfig directory usually appears last in the configuration path, so that any properties defined there override default system settings.
For example, suppose you change the port number for Oracle ATG Web Commerce’s internal RMI server, by setting the rmiPort property of the /atg/dynamo/Configuration component, and save the new value in the localconfig directory. The next time you start the application, Nucleus will take the value of the rmiPort property from localconfig, because it is the last directory in your configuration path.
Any changes you make to localconfig are preserved when you install a new Oracle ATG Web Commerce version.
For more information on modules, configuration layers, and properties files, see the Nucleus: Organizing JavaBean Components and the Working with Application Modules chapters of the ATG Platform Programming Guide.
