Debugging parallel applications is most of the times a hard and complex task. Debugging multiple processes that run on multiple machines can be an almost impossible mission if performed without the right tools. An MPI library that integrates easily with the right graphical debugger, allows the developer to control and debug the whole computation from a single interface, making its life a lot easier by reducing the complexity of the debugging task.

The Distributed Debugging Tool, developed by Streamline Computing, is a comprehensive graphical debugger designed for the complex task of debugging parallel code. DDT has a unique and intuitive graphical interface that puts you in control of your parallel application, whether you are working with 4 processes on a workstation or 1024 across a high-performance cluster. Trial versions of DDT and more detailed information can be found in Streamline Computing's website at:

We have tested DDT 1.6 for Linux distributions on Intel 32bit architectures. In order to use DDT, you must install the csWMPI II's MPICH compatibility layer.

In order for csWMPI II knows where to find DDT, a number of environment variables needs to be set in the csWMPI II2serviced startup script. csWMPI II default scripts assume that DDT is installed in /usr/local/ddt. If this is not your case, please edit the file /etc/init.d/csWMPI II2serviced, set the variable DDTPATH with your DDT installation directory and restart the csWMPI II2serviced.

When running DDT, please specify the MPI implementation as generic. DDT will use the mpirun command provided in the MPICH compatibility layer.

Please refer to DDT documentation for further information on how to configure and use it.