A fault identification algorithm for ti-diagnosable systems
IEEE Transactions on Computers - The MIT Press scientific computation series
The consensus problem in fault-tolerant computing
ACM Computing Surveys (CSUR)
| Hi-index | 14.98 |
Hybrid fault diagnosability in distributed multiprocessor systems is considered for the case in which, in addition to units being faulty, communication links among units can also be faulty. A hybrid fault situation is a (bounded) combination of hard and soft failing units. A novel hybrid fault diagnosability, denoted (t/t/sub s/-unit: sigma -link)-diagnosability is introduced (a total of t or fewer units can be faulty with at most t/sub s/ of them soft-failing; sigma is the number of incorrect test outcomes caused by unreliable links)., This diagnosability is compatible with the previously known t/t/sub s/-diagnosability and can additionally tolerate up to sigma incorrect test outcomes to give always-correct diagnosis for any hybrid-fault (HF)-compatible syndrome from a hybrid fault situation. It is shown that an O( mod E mod ) algorithm, proposed originally by the authors for faulty unit identification in t/sub s/-diagnosable systems, can be used to analyze a syndrome from a (t/sub s/-unit sigma -link)-diagnosable system efficiently without any preclassification of the syndrome in terms of HF-compatibility. It is shown that this algorithm not only identifies all the faulty units associated with an HF-compatible syndrome but also produces nonempty, always-correct diagnosis for many HF-incompatible syndromes.