Dynamic fault tolerance in DCMA-a dynamically configurable multicomputer architecture

This paper introduces a new architecture for a fault-tolerant computer system which connects high-end PCs or workstations by a high-speed network. To achieve platform independence, coupling is based on the widely used PCI-bus. In contrast to commercially available fault-tolerant systems we strongly emphasize mechanisms for tolerating transient and intermittent faults. To keep hardware costs low the system is built with off-the-shelf computers and their extensions are kept as small as possible. To reduce the operational costs the system can be dynamically adapted to different demands on fault tolerance on a program-by-program basis. Adaptation is done transparently to the application software by the operating system. We use a commercially available real-time operating system with a POSIX-compliant UNIX-interface. The bandwidth of fault tolerance reaches from a non-redundant system of stand-alone computers, a master/checker configuration to a TMR-system. The high-performance network allows the system to operate as a parallel multicomputer, too.