An approach to experimental evaluation of real-time fault-tolerant distributed computing schemes

A test-based approach to the evaluation of fault-tolerant distributed-computing schemes is discussed. The approach is based on experimental incorporation of system structuring and design techniques into real-time distributed computing testbeds centered around tightly coupled microcomputer networks. The effectiveness of this approach has been experimentally confirmed. Primary advantages of the testbed-based approach include the relatively high accuracy of the data obtained on timing and logical complexity, as well as the relatively high degree of assurance that can be obtained on the practical effectiveness of the scheme evaluated. Various design issues encountered in the course of establishing the basic microcomputer network testbed facilities are discussed, along with their augmentation to support some experiments. The shortcomings of the testbeds that have been recognized are also discussed together with the desired extensions of the testbeds. Some of the desired extensions are beyond the state-of-the-art in microcomputer network implementation