Each module can have its own log4j.properties file, which is placed in the same directory as the module.properties file. The collection of log4j.properties files within all modules installed into the SkyVault.war act collectively to augment/override the global WEB-INF/classes/log4j.properties file.
You can control the logging levels of classes within your module without having to modify the main log4j.properties file; this also allows the logging configuration of a module to be handled cleanly by the Module Management Tool.
Given that {module.id} denotes the value of module.id set in module.properties, your log4j.properties file should be put in the following position within the source code directory structure of your module:
config/alfresco/module/{module.id}/log4j.properties
At deployment time, this file will be copied to:
WEB-INF/classes/alfresco/module/{module.id}/log4j.properties
For example, if module.id=sample, then in the module's source tree you'll have:
config/alfresco/module/sample/log4j.properties
On the servlet container, your module's log4j.properties file will be deployed to:
WEB-INF/classes/alfresco/module/sample/log4j.properties
If you wish to configure Log4j properties in the extensions that aren't packaged as AMP modules, you can create log4j.properties file of the form: {name}-log4j.properties and place it within the SkyVault/extension directory on the server's classpath. These properties override the module log4.properties files. For example:
WEB-INF/classes/alfresco/extension/SIMPLE_EXAMPLE-log4j.properties
Finally, developers might also wish to maintain a dev-log4j.properties file outside of the webapp. This allows for changing Log4j settings without touching the "shipping product", or any of a customer's local settings. Your optional dev-log4j.properties file should be in the SkyVault/extension directory within the server's classpath, and outside the webapp itself (so you don't accidentally delete it). The dev-log4j.properties file augments/overrides all others. For example:
$TOMCAT_HOME/shared/classes/alfresco/extension/dev-log4j.properties
Best Log4j Configuration Practices
Local customizations/licenses are kept outside of the webapp. For example:
$TOMCAT_HOME/shared/classes/alfresco/extension/...-log4j.properties
Shipping config files should be located within the webapp. For example:
WEB-INF/classes/alfresco/extension/...-log4j.properties
A dev-log4j.properties file should never be used in an ongoing during production, nor packaged as a part of any product.
Advanced log4j.properties Configuration
In the unlikely event that you need to configure the set directories SkyVault Community Edition uses to find module-specific log4j.properties files, look at WEB-INF/classes/alfresco/core-services-context.xml and find a bean definition fragment that looks something like:
<property name="overriding_log4j_properties">
<list>
<!-- NOTE: value entries are listed from lowest precedence to highest. -->
<!-- Installed AMP modules -->
<value>classpath*:alfresco/module/*/log4j.properties</value>
<!-- Other installed extensions -->
<value>classpath*:alfresco/extension/*-log4j.properties</value>
<!-- private developer overrides -->
<value>classpath*:alfresco/extension/dev-log4j.properties</value>
</list>
</property>
You can add additional path expressions here; for more information on the classpath*: notation used here, see Spring's PathMatchingResourcePatternResolver documentation. Generally this file will not need to be changed.