This paper describes Net-dbx, a tool that utilizes Java and other World Wid
e Web tools for the debugging of MPI programs from anywhere in the Internet
. Net-dbx is a source-level interactive debugger with the full power of gdb
(the GNU Debugger) augmented with the debug functionality of the public-do
main MPI implementation environments. The main effort was on a low overhead
, yet powerful, graphical interface supported by low-bandwidth connections.
The portability of the tool is of great importance as well because it enab
les the tool to be used on heterogeneous nodes that participate in an MPI m
ulticomputer. Both needs are satisfied a great deal by the use of WWW brows
ing tools and the Java programming language. The user of our system simply
points his/her browser to the Net-dbx page, logs in to the destination syst
em, and starts debugging by interacting with the tool, just as with any GUI
environment. The user can dynamically select which MPI processes to view/d
ebug. A special WWW-based environment has been designed and implemented to
host the system prototype.