Eclipse's PTP tools allow you to perform parallel debugging. This means you can create a breakpoint in your parallel code and be able to stop each process (one for each node in the cluster) and inspect their state. The instructions below briefly describe parallel debugging in Eclipse.

NOTE: You must create a parallel run for your project before attempting to debug it. Follow the steps in the section called “Setting Up a Parallel Run” if you haven't done so already.

1. Edit the source file you want to debug in either the C/C++ or Fortran perspective (see section entitled “How to Switch Perspectives”)
2. Set a parallel break point by right clicking the grey area to the left of the line of code in question and selecting Parallel Breakpoint → Toggle Parallel Breakpoint
3. Switch to the PTP Debugging Perspective (see section entitled “How to Switch Perspectives”)
4. Start the debugging session by clicking the icon and selecting your project from the list.
   
5. The debugger should load showing you 4 tasks (the diamond shaped icons). Double clicking any of these will refresh the variable list with its values. From here you can choose to resume operation, step into, or step over a code block.
   

For a more detailed description of the Parallel Debugging perspective, see the section entitled “PTP Debug Perspective” under the "Switching Workspace Perspectives" subsection.