Fault Tolerance Issue in Wired Mesh, Torus Network

The Parallel computers, such as multiprocessors system-on-chip (Mp-SoCs), multicomputers and cluster computers are consisting of hundreds or thousands multiple processing units and components (such as routers, channels and connectors) connected via some interconnection network that collectively may undergo high failure rates. Normally, the faulty components are coalesced into fault regions, which are classified into two major categories: convex and concave regions [1]. In this paper, we propose the occurrences of common fault patterns in torus and mesh interconnection networks which includes both Convex (|-shaped, , -shaped) and concave (L-shaped, T-shaped, +-shaped, H-shaped) regions. Fault rings can be used to guide messages bypass faulty nodes/links in a fault tolerant interconnection network. However, nodes on the fault ring become hot spots, thus causing uneven distribution of the traffic loads. To avoid such traffic congestion, a concept of the balanced ring is proposed in this paper. However the algorithm presented in [2] for the formation of balanced ring has the demerits that it involves all the nodes of the network each time a balanced ring needs to form, thereby increasing overhead to the whole system. In this paper, we present an improved algorithm for the formation of balanced ring by considering only the nodes on the fault ring in contrast to all [3].