Reliability Analysis of Service Composition with Service Pools and Optimal Configuration of Service Pool Size

Abstract

The reliability of applications in Cloud will be highly affected by the reliability of underlying service component. Service pools with redundant services are mainly used to improve the reliability of service composition. This chapter proposes an optimal service pool size configuration method aiming at minimizing the overall cost or response time of service composition while meeting certain reliability constraints. The reliability, cost, and response time analysis of service composition with multiple service pools is first analyzed using probability analysis method and architecture-based approach. After that, the optimization problem is presented and classified into three categories. For single-objective problems, a dynamic programming algorithm is presented to get near-optimal solutions. For multi-objective problems, a hybrid genetic algorithm is proposed to search nondominated sets of solutions. This hybrid genetic algorithm employs a sensitivity-based local search operator. Empirical studies results showed that the algorithms could find optimal solutions for the three kinds of problems and they outperformed the exiting approaches including greedy selection method and traditional genetic algorithms.