To follow step by step the execution of a Job to identify possible bugs, you can run it in Debug mode.
To access the Debug mode:
Click the Run view to access it.
Click the Debug Run tab to access the debug execution modes.
Before running your Job in Debug mode, add breakpoints to the major steps of your Job flow.
This will allow you to get the Job to automatically stop at each breakpoint. This way, components and their respective variables can be verified individually and debugged if required.
To add breakpoints to a component, right-click it on the design workspace, and select Add breakpoint on the contextual menu.
A pause icon displays next to the component where the break is added.
To switch to debug mode, click the Java Debug button on the Debug Run tab of the Run panel. Talend Studio's main window gets reorganized for debugging.
You can then run the Job step by step and check each breakpoint component for the expected behavior and variable values.
To switch back to Talend Studio designer mode, click Window, then Perspective and select Integration.