Masking Faults While Providing Bounded-Time Phased Recovery
نویسندگان
چکیده
We focus on synthesis techniques for transforming existing fault-intolerant real-time programs to fault-tolerant programs that provide phased recovery. A fault-tolerant program is one that satisfies its safety and liveness specifications as well as timing constraints in the presence of faults. We argue that in many commonly considered programs (especially in mission-critical systems), when faults occur, simple recovery to the program’s normal behavior is necessary, but not sufficient. For such programs, it is necessary that recovery is accomplished in a sequence of phases, each ensuring that the program satisfies certain properties. In this paper, we show that, in general, synthesizing fault-tolerant real-time programs that provide bounded-time phased recovery is NP-complete. We also characterize a sufficient condition for cases where synthesizing fault-tolerant real-time programs that provide bounded-time phased recovery can be accomplished in polynomial-time in the size of the input program’s region graph.
منابع مشابه
Synthesizing Bounded-Time 2-Phase Recovery
We focus on synthesis techniques for transforming existing fault-intolerant real-time programs into fault-tolerant programs that provide phased recovery. A faulttolerant program is one that satisfies its safety and liveness specifications as well as timing constraints in the presence of faults. We argue that in many commonly considered programs (especially in mission-critical systems), when fau...
متن کاملIncremental Synthesis of Fault-Tolerant Real-Time Programs
In this paper, we focus on the problem of automated addition of faulttolerance to an existing fault-intolerant real-time program. We consider three levels of fault-tolerance, namely nonmasking, failsafe, and masking, based on safety and liveness properties satisfied in the presence of faults. More specifically, a nonmasking (respectively, failsafe, masking) program satisfies liveness (respectiv...
متن کاملZone-based Synthesis of Timed Models with Strict Phased Fault Recovery
In this paper, we focus on efficient synthesis of fault-tolerant timed models from their fault-intolerant version. Although the complexity of the synthesis problem is known to be polynomial time in the size of the time-abstract bisimulation of the input model, the state of the art currently lacks synthesis algorithms that can be efficiently implemented. We propose an algorithm that takes a time...
متن کاملAutomatic Addition of Fault-Tolerance to Real-Time Programs
In this paper, we focus on automated addition of fault-tolerance to an existing fault-intolerant realtime program. We consider three levels of fault-tolerance, failsafe, nonmasking, and masking, based on the properties satisfied in the presence of faults. Furthermore, for failsafe and masking fault-tolerance, we introduce two cases, soft and hard, based on satisfaction of timing constraints in ...
متن کاملSymbolic Synthesis of Timed Models with Strict 2-Phase Fault Recovery
In this article, we focus on efficient synthesis of fault-tolerant timed models from their fault-intolerant version. Although the complexity of the synthesis problem is known to be polynomial time in the size of the time-abstract bisimulation of the input model, the state of the art currently lacks synthesis algorithms that can be efficiently implemented. This is in part due to the fact that sy...
متن کامل