Title :
Redundant task-allocation in multicomputer systems
Author :
Cherkassky, Vladimir ; Chen, Chien-In Henry
Author_Institution :
Dept. of Electr. Eng., Minnesota Univ., Minneapolis, MN, USA
fDate :
9/1/1992 12:00:00 AM
Abstract :
A simple yet effective method for improving multicomputer multiprocessor system reliability via redundant allocation of tasks to computers (processors) is described. Given any known (nonredundant) scheduling strategy, tasks are allocated to processors statically and redundantly using a k-circular shifting (KCS) algorithm. so that if some processors fail during the execution. all tasks can be completed on the remaining processors (but at a longer time). Redundant allocation of independent tasks to identical processors (computers), subject to real-time constraints on total execution time, is discussed in detail, and analytic reliability estimates are derived. The longest processing time scheduling is given as an example of nonredundant deterministic scheduling of independent tasks. Processor utilization for redundant task-allocation is discussed and compared with standby redundancy: the authors´ KCS algorithm achieves much higher processor utilization than standby redundancy
Keywords :
fault tolerant computing; multiprocessing systems; redundancy; scheduling; KCS algorithm; analytic reliability estimates; fault tolerant systems; k-circular shifting; longest processing time scheduling; multicomputer multiprocessor system reliability; nonredundant deterministic scheduling; real-time constraints; redundant task-allocation; scheduling strategy; standby redundancy; total execution time; Degradation; Fault tolerant systems; Hardware; Multiprocessing systems; Parallel processing; Processor scheduling; Redundancy; Reliability; Scheduling algorithm; Throughput;
Journal_Title :
Reliability, IEEE Transactions on
