Fault indicator

About: Fault indicator is a research topic. Over the lifetime, 10057 publications have been published within this topic receiving 143482 citations. The topic is also known as: FCI & power line fault indicator.

Toward Reducing Fault Fix Time: Understanding Developer Behavior for the Design of Automated Fault Detection Tools

Abstract: The longer a fault remains in the code from the time it was injected, the more time it will take to fix the fault. Increasingly, automated fault detection (AFD) tools are providing developers with prompt feedback on recently-introduced faults to reduce fault fix time. If however, the frequency and content of this feedback does not match the developer's goals and/or workflow, the developer may ignore the information. We conducted a controlled study with 18 developers to explore what factors are used by developers to decide whether or not to address a fault when notified of the error. The findings of our study lead to several conjectures about the design of AFD tools to effectively notify developers of faults in the coding phase. The AFD tools should present fault information that is relevant to the primary programming task with accurate and precise descriptions. The fault severity and the specific timing of fault notification should be customizable. Finally, the AFD tool must be accurate and reliable to build trust with the developer.

Distributed on-line diagnosis in the presence of arbitrary faults

Abstract: This paper introduces a new fault model for system-level diagnosis and a class of online distributed diagnosis algorithms that operate correctly in the presence of fault nodes that disseminate arbitrarily corrupted diagnostic information. The fault model addresses the practical issue of designing an internode test to cover diagnosis algorithm operation. Since an explicit test to detect arbitrary failures is not practical, evidence of a node's faulty behavior is provided by examining diagnositic messages exchanged by the node. In many practical systems, algorithm overhead using the new fault model is only twice that required for algorithms using the PMC fault model. The key results include a description of the new fault model, the specification of a class of online distributed diagnosis algorithms that use this fault model, and proofs of their correctness.

Path-based fault correlations

Abstract: Although a number of automatic tools have been developed to detect faults, much of the diagnosis is still being done manually. To help with the diagnostic tasks, we formally introduce fault correlation, a causal relationship between faults. We statically determine correlations based on the expected dynamic behavior of a fault. If the occurrence of one fault causes another fault to occur, we say they are correlated. With the identification of the correlated faults, we can better understand fault behaviors and the risks of faults. If one fault is uniquely correlated with another, we know fixing the first fault will fix the other. Correlated faults can be grouped, enabling prioritization of diagnoses of the fault groups. In this paper, we develop an interprocedural, path-sensitive, and scalable algorithm to automatically compute correlated faults in a program. In our approach, we first statically detect faults and determine their error states. By propagating the effects of the error state along a path, we detect the correlation of pairs of faults. We automatically construct a correlation graph which shows how correlations occur among multiple faults and along different paths. Guided by a correlation graph, we can reduce the number of faults required for diagnosis to find root causes. We implemented our correlation algorithm and found through experimentation that faults involved in the correlations can be of different types and located in different procedures. Using correlation information, we are able to automate diagnostic tasks that previously had to be done manually.

Distributed fault isolation and recovery system and method

Abstract: There is disclosed a system and a method for isolating faults and recovering a distributed system of the type including a plurality of modules to optimized operation. At least some of the modules are active fault recovery modules and include fault detecting means for initializing a fault check routine and sensing faults within the distributed system. Voting means are associated with each active module for placing a vote during each fault check routine in response to a detected fault. Collective vote determining means record the votes of the active modules after each fault check routine and recovery sequence initializing means initializes a fault isolation and recovery sequence in response to a given number of consecutive collective votes exceeding a predetermined value.