Avoiding Communication Hot-Spots in Interconnection Networks

In creating interconnection networks for parallel computers an efficient design is crucial because of its impact on the performance. A high speed routing scheme that minimises contention and avoids the formation of hot-spots should be included. We have developed a new method to uniformly balance communication traffic over the interconnection network called Distributed Routing Balancing (DRB) based on limited and load-controlled path expansion in order to maintain low message latency. DRB defines how to create alternative paths to expand single paths (expanded path definition) and when to use them depending on traffic load (expanded path selection). Evaluation in terms of latency and bandwidth is presented. Some conclusions and comparisons with existing methods are given. It is demonstrated that DRB is a method to effectively balance network traffic.