The structure of System/88, a fault-tolerant computer

In recent years, there has been a growing requirement for continuous processing capability approaching 24 hours per day, 7 days per week. Industries such as finance, transportation, securities, and telecommunications have continuous-availability requirements that can approach downtimes of not more than three minutes per year. This paper describes configurations of the Stratus/32 continuous processing computer system that are marketed as the IBM System/88 through an agreement with Stratus Computer, Inc. The system achieves its fault tolerance via hardware duplexing coupled with a distributed operating system that allows system resources to be distributed over many separate computers while maintaining a single systems image to the end user. This single systems image may also be extended across a network of multiple systems. The way in which software makes this distribution possible and the way in which system resources are named to allow transparent distribution across the system are described in the paper. Also described are the transaction processing services that are part of the operating system and allow transaction programs to be written to operate effectively over the distributed system, by means of a requester-server structured approach.