Applying randomized edge coloring algorithms to distributed communication: an experimental study

We propose a parameterized, randomized edge coloring algorithm for use in coordinating data transfers in fully connected distributed architectures such as parallel 1/0 subsystems and multimedia information systems. Our approach is to preschedule 1/0 requests to eliminate contention for 1/0 ports while maintaining an efficient use of bandwidth. Request scheduling is equivalent to edge coloring a bipartite graph representing pending 1/0 requests. Although efficient optimal algorithms exist for centralized edge coloring where the global request graph is known, in distributed architectures heuristics must be used. We propose such heuristics and use experimental analysis to determine their ability to approach the centralized optimal. The performance of our algorithms is also compared with the work of other researchers experimentally. Our results show that our algorithms produce schedules within 5% of the optimal schedule, a substantial improvement over existing algorithms. The use of experimental analysis allows us to evaluate the appropriateness of each heuristic for a variety of different architectural models and applications.