Nimrod

GriddLeS

Grid computing poses someinteresting challenges for software development, because programs must run on a variety of different hardware and software platforms.

Relative debugging is a technique that allows a user to compare data between two executing programs. It was devised to aid the testing and debugging of programs that are either modified in some way, or are ported to other computer platforms. It is effectively a hyrbid test & debug methodology.

We have developed a relative debugger called Guard to aid the testing and debugging of software developed for the Grid.

Three different versions of Guard have been produced. One targets traditional Unix computers and is command line driven. Another leverages the Microsoft Visual Studio .NET ® platform and targets Windows platforms. Another is built on IBM's Eclipse platform, and is available for both Linux and Windows.

All three versions are available from Guardsoft.

Whilst traditional debuggers force the programmer to understand the expected state and internal operation of a program, relative debugging makes it possible to trace errors by comparing the contents of data structures between programs at run time. In this way, the programmer is less concerned with the actual state of the program, and more concerned with finding when and where differences between the old and new codes occur. The methodology requires users to start by observing that two programs generate different results, and then iteratively moving back through the data flow of the codes to determine the point at which they start producing different answers.

At the IEEE Supercomputing (SC2003) in Phoenix, Arizona, we demonstrated Guard at the Microsoft booth.

Come and see how Guard can solve your software porting problems ....