Reliability-aware automatic composition approach for web services

• Published in: Science China. Information sciences Vol. 55; no. 4; pp. 921 - 937
• Main Authors: Li, Mu, Li, Bo, Huai, JinPeng
• Format: Journal Article
• Language: English
• Published: Heidelberg SP Science China Press 01.04.2012; Springer Nature B.V
• Subjects: Algorithms; Composition; Computation; Computer Science; Information Systems and Communication Service; Logic; Materials handling; Reliability; Research Paper; Specifications; Synthesis; Trees; Web services; Web服务组合; 可靠性; 合成模式; 感知; 时间算法; 组合方法; 综合模型; 计算树逻辑; heuristic algorithm; synthesis model; web services; reliability; synthesis problem
• ISSN: 1674-733X; 1869-1919
• DOI: 10.1007/s11432-011-4545-8

In this paper, we study the reliability-aware synthesis problem for composing available services automatically and guaranteeing that the composed result satisfies the specification, such as temporal constraints of functionality and reliability, centered on a synthesis model for mediator of web services composition （CSM）. This approach focuses on handling attributes and state relations, and permitting users and services to operate over them, i.e., read/write their data values and compare them according to a dense state order. We show that the reliability-aware synthesis problem for the specification is EXPTIME-complete and we give an exponential- time algorithm （CSM-NSA） which for a given formula ~ and a synthesis model, synthesizes available services in the library satisfying ~ over the synthesis model （if they exist） or responds with ＂not satisfiable＂ （otherwise）. The specification ~ is a fragment of PCTL （probabilistic computation tree logic）, obtained from ＂ordinary＂ CTL （computation tree logic） by replacing the EX, AX, EU and AU operation with their quantitative counterparts X〉p, X=1, U〉p, and U=1, respectively. As opposed to NSA, we provide a more effective algorithm to replace the NSA algorithm called CSM-HSA （heuristic synthesis algorithm）. Though HSA is an incomplete algorithm, the answer is correct. The experiments show that the HSA algorithm solves the problem of reliability-aware service synthesis effectively and efficiently.