Graphical monitoring of distributed systems
A tool for the animation of message interactions between concurrent processes is presented. Each message interaction, such as a send or receive, has a corresponding static graphical representation. The interactions among the processes of an executing distributed computation are represented by an animated sequence of these static images. This graphical monitoring tool, called Mona, is part of a distributed software prototyping environment, called Jade. The Jade environment supports the implementation of distributed programs written in ADA, C, Lisp, Prolog, and Simula. The execution of these multi-lingual programs can be distributed over a loosely coupled network of Vax/Unix systems and microcomputer workstations. Preliminary experience using Mona to develop distributed programs is also reported. In particular, the application of Mona to the debugging of a distributed implementation of a workstation virtual terminal window system is described. We also discuss the advantages of graphical monitoring over more traditional approaches, i.e. textual tracing.