Active Backup Systems--A Reliable Multiprocessor Cluster.

An active backup system is based on a client/server model where the server cluster consists of loosely coupled processors viewed as a single machine. Under normal operation, clients generate requests for the servers and the servers process these requests. Three major goals describe the different aspects of this work. The first goal is to design a server cluster that maintains data integrity and client service in the event of a server failure. A second goal is to design a server cluster that is extensible--a system that can easily adapt to increased demand for memory and processing capacity. A third goal is to design a server cluster that can tolerate more than a single fault. The first goal is a fundamental requirement for a server cluster while the second and third goals are enhancements that demonstrate the generality of our design. The primary outcome of this effort is a reliable partitioning model used to partition client requests within the server cluster.