AN ARCHITECTURE FOR HIGH AVAILABILITY MULTIUSER SYSTEMS

This paper describes fault tolerance features of a multiprocessor syst em called SPAX (Scalable parallel Architecture based on X-bar network) . It aims at a cost-effective reliable multiprocessor system for both scientific and business applications. The system can be composed of up to sixteen clusters. Each cluster consists of eight nodes which can b e any combination of processing nodes, input/output nodes and communic ation nodes. The system is designed to eliminate potential single-poin ts of failures such as loss of a processor, loss of a network, or loss of a disk drive. Xcent-Net, which is a duplicated hierarchical crossb ar interconnection network built into the system, supports dual paths to every node with high bandwidth and with low latency. Each node is d esigned to support multi-level fault tolerance enabling a user to choo se the level of fault tolerance with a possible resource or performanc e penalty. The system has been implemented at ETRI. (C) 1997 Elsevier Science B.V.