Your Talend Studio includes the Apache logging utility log4j to provide logging at runtime. You can enable or disable log4j loggers in components and customize the log4j configuration globally for the project.
To do so:
On the toolbar of the Studio main window, click or click File > Edit Project Properties from the menu bar to open the [Project Settings] dialog box.
In the tree view of the dialog box, click the Log4j node to open the Log4j view.
Select the Activate log4j in components check box to activate the log4j feature.
By default, the log4j feature is activated when a project is created.
Change the global log4j configuration by modifying the XML instructions in the Log4j template area.
For example, to configure the root logger to output all debug or higher messages, go to the Root Logger section and set the value attribute of the priority element of the root node to debug.
For more information on the log4j parameters, see http://wiki.apache.org/logging-log4j/Log4jXmlFormat.
You can also define the output level of log messages to override the global configuration at Job execution. For more information, see How to customize log4j output level at runtime.