The PDBG Process-level Debugger for Parallel and Distributed Programs

In this paper we discuss several issues concerning the design and implementation of a debugger for parallel and distributed applications. This debugger uses a clientserver approach to isolate the debugging user-interface from the debugging services, by way of a two-level structured approach: the component-level to observe and act upon individual processes; and the coordination-level to observe the interprocess relations and act upon them. A formal specification of the expected behavior of a processes under debugging is presented, and the debugging functionalities required to support this model are evaluated and its implementation described. Special relevance is given to the tool-interfacing support functionalities of the debugger and how they were implemented. 1 On Debugging Parallel and Dis-