Dynamic Routing Balancing in Parallel Computer Interconnection Networks

Abstract

In creating interconnection networks, an efficient design is crucial because of its impact on the parallel computer performance. A routing scheme that minimises contention and avoids the formation of hot-spots should be included in the design. Static schemes are not able to adapt to traffic conditions. We have developed a new method to uniformly distribute traffic over the network, called Distributed Routing Balancing (DRB), that is based on limited and load-controlled path expansion in order to maintain a low message latency. The method uniformly balances the communication load between all links of the interconnection network and maintains a controlled latency, provided that total bandwidth requirements do not exceed the total link bandwidth available in the interconnection network. 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 policies). We explain the DRB principles and show the performance evaluation of the method carried out by simulation.