Techniques and applications of computation slicing

作     者：Mittal, N Garg, VK 

作者机构：Univ Texas Dept Comp Sci Richardson TX 75083 USA Univ Texas Dept Elect & Comp Engn Austin TX 78712 USA 

出 版 物：《DISTRIBUTED COMPUTING》 (分布式计算)

年 卷 期：2005年第17卷第3期

页      面：251-277页

核心收录：

学科分类：08[工学] 0812[工学-计算机科学与技术（可授工学、理学学位）] 

主　　题：analyzing distributed computation predicate detection predicate control global property evaluation testing and debugging software fault tolerance 

摘      要：Writing correct distributed programs is hard. In spite of extensive testing and debugging, software faults persist even in commercial grade software. Many distributed systems should be able to operate properly even in the presence of software faults. Monitoring the execution of a distributed system, and, on detecting a fault, initiating the appropriate corrective action is an important way to tolerate such faults. This gives rise to the predicate detection problem which requires finding whether there exists a consistent cut of a given computation that satisfies a given global predicate. Detecting a predicate in a computation is, however, an NP-complete problem in general. In order to ameliorate the associated combinatorial explosion problem, we introduce the notion of computation slice. Formally, the slice of a computation with respect to a predicate is a (sub)computation with the least number of consistent cuts that contains all consistent cuts of the computation satisfying the predicate. Intuitively, slice is a concise representation of those consistent cuts of a computation that satisfy a certain condition. To detect a predicate, rather than searching the state-space of the computation, it is much more efficient to search the state-space of the slice. We prove that the slice of a computation is uniquely defined for all predicates. We also present efficient algorithms for computing the slice for several useful classes of predicates. For an arbitrary predicate, we establish that the problem of computing the slice is NP-complete in general. Nonetheless, for such a predicate, we develop an efficient heuristic algorithm for computing an approximate slice. Our experimental results demonstrate that slicing can lead to an exponential improvement over existing techniques for predicate detection in terms of time and space.