Fault-tolerant routing in SCI networks

Abstract

Fault-tolerant routing has been a hot topic in the academic community for quite some time now, and several different approaches have been suggested. In the interconnect industry however, fault-tolerant routing has not been implemented to the same extent. In this thesis we have adapted and implemented a local fault-tolerant routing approach in SCI interconnect technology produced by Dolphin Interconnect Solutions. The existing technology used in SCI is based in a static reconfiguration approach, where the traffic is disabled, while the new routing is calculated by a central front-end and distributed out to the nodes.

Our algorithm builds upon the principle of enabling the nodes to make routing decisions from the information that is available to them locally, and having the rest of the nodes in the cluster to be prepared for this unexpected traffic. The algorithm has been tested on real hardware, and we have shown that it can handle several levels of traffic in the network. The test has also proven that our method gives the same performance both before and after the error occurs if the packets have the same conditions, such as competing traffic and link length. Our routing algorithm is currently integrated as a part of Dolphin Interconnect Solutions driver in the last official release.