On debugging in a parallel system

A description is given of a partly implemented parallel debugger for the Twente University multicomputer (TUMUKT). The system's basic method for exchange of data is message passing. Experience indicates that most programming errors in application software are made in calls to the kernel and the interprocess communication. The debugger is intended to be used for locating bugs at this level in the application software. The main features of the debugger are the following: it is event based, using a monitor for intercepting these events; record and replay are the main debugging techniques; preprocessing of events is done by programmable filters; and the user interface is graphical, using grouping as the main abstraction mechanism.<>