Designing general-purpose fault-tolerant distributed systems-a layered approach

General-purpose distributed systems comprised of computing nodes with different characteristics and connected by high-speed communication networks are very popular these days. The development of a dependable distributed system, however, necessitates the use of various techniques including fault tolerance to avert occurrences of failures or system malfunction. The ad hoc techniques of adding redundancy to improve reliability are not always suitable in these circumstances because of excessive design cost. Redundancies have to be allocated at various hardware and software levels in order to optimize their utilization in the system. This paper considers the design of general-purpose fault-tolerant distributed systems based on a layered approach. The benefits of the layered approach in the process of allocation of redundancy and fault tolerance at various system levels are presented and analyzed in the paper.